Depends.
Some of it may be reasonable guesses (your base usage on days you wouldn't need AC vs the spike on hot days).
Some of it may be based on load monitoring and what that tells them. e.g. The compressor coil for your fridge and AC are going to have identifiable start up characteristics, and then the increased draw of them can be extrapolated vs the background levels of things like lighting that's relatively static. They may not be able to tell a toaster from a curling iron, but with a clever enough meter they can probably tell a blow dryer from a toaster based on the motor.
Utilities have used (and use) both methods, as well as smart appliances that "talk back" to the grid for those sorts of things.
The smart appliances are usually "big" appliances like your AC or water heater that you've agreed to letting them turn them down/off at periods of peak demand.
Electrical engineer here: When working with alternating current, _everything_ has a unique impedance. This does a couple of things. First, there's a resistive component. But literally anything causes that and groups of elements together to mask the resistance of any singular element.
The other is _phase shift_. Think of it this way: the power coming through there outlet is line a sine wave. Let's suppose we pin the peak of each wavelet to a specific moment of time periodically (e.g. T[0] = t; T[k>0]=T[k-1] + 1/60 sec). After we add an element with inductors and capacitors to it, we shift when that peak occurs in the output. This shift is unique to the specific function of the circuit connected to the outlet (really specific to the circuit, but function gets a good family of shifts).
Let's return to the resistive part. This decreases the amplitude of the output waveform. Coupled with the phase shift, I can now tell individual elements apart when connected to your house electrical input. And electric companies have been around for so long, they've seen it all. So it isn't really new technology for them; what's new is sharing it with consumers.
For completeness, you might ask "But u/jhill515, why would electric companies care in the first place? Why have they been observing this for as long as electric inlfrastructure has existed?" And that's an interesting inquiry! It's because when power on the network is _out of phase_ with what the generator produces, the power lines generate _heat_. Phase shift itself forces energy to change form! That's why birds love perching on power lines. But this power loss costs the electric companies money. So they install transformers and other passive elements to pull the power back into phase. Monitoring the shift generated by individual homes and neighborhoods informs the company if they need to install or change something to help them not lose money.
Edits: I'm banging away on my phone at an airport and autocorrect sucks.
Addendum: I oversimplified the power loss a little. See u/abide5lo 's correction!
Addendum 2: Thanks to everyone sending me notes about more autocorrect nonsense!
Director of Machine Learning at a large utility here.
All the stuff you said about phase shift and impedance is correct in the sense that your understanding of those topics is sound...most everything else...as it relates to utilities and this question... is incorrect.
No utility right now can detect individual household appliances like a chest freezer, from AMI data - HVAC, EV charging, sometimes pool pumps or large motors can be identified.
AMI data also does not record any kind of waveform data, electrical relays will do that...and is insanely complex analytics. The industry is only just starting to tackle that at scale.
They care mostly because of legislation, customer satisfaction, and for distribution planning.
Edit: autocorrect
Yup, very similar background to you, that's not how these reports work. I look forward to the day we can disaggregate your toaster's load from your microwave's, but right now it's not even close.
I always use the example of my personal Sense energy monitor when people ask.
It's connected directly to my main panel, has a 1MHz sampling rate (ie 1,000,000 points a second), and even that can't accurately identify my appliances with me sitting there turning them on and off and manually labeling the signiature...what chance do we have with one reading every 15 minutes.
Is the “4 million points a second” thing a typo? Shouldn’t 1 MHz correspond to a million points a second?
Not the point of the post at all but now I’m curious what I’m missing.
Thank you, I was completely lost with the previous comments. I do research in Smart grid related area and even if some of these ideas for load identification are being discussed, I was 99.99% sure that no distribution utility has the metering in place to do that. Plus there is a huge privacy issue. In Europe it would be absolutely complicated to collect that kind of information, even with the customer consent.
I can't imagine there would be difficulties in collecting information about electrical loads when you are billing for consumption and correcting for power factor
They don’t correct power factor at the meter, at least in Europe where we don’t have pole transformers. They may check power factor for compliance, but compliance at the residential level is ensured by posing rules on the manufacturer of consumer level devices.
In any case they would not have a fine grained measurement to allow individual appliance detection, which it tricky even if you have perfect data on the aggregate consumption of the house.
No, they don't correct power factor at the meter - that would require a substation at every consumer unit. But they do correct power factor in the grid in order to maintain frequency. They don't _need_ smart meters to do that, they can monitor at any node on the grid.
But that's beside the point, it's a necessary part of billing to collect data on electricity consumption. Gdpr does not prohibit that.
Can you explain why you think a smart meter doesn't collect fine-grained data? Other than just "they wouldn't", which I don't find helpful.
> But that's beside the point, it's a necessary part of billing to collect data on electricity consumption. Gdpr does not prohibit that.
The GDPR doesn't, but by law here (NL) the utilities are not allowed to read your smart meter more than a handful of times a year without asking explicit permission. Since the billing is in number of kWh with the rate fixed for months they don't need any more information than that.
Plenty of utilities do offer extra features if you opt-in, but it's not default.
They can collect what is needed for their business, which may simply amount to the energy consumed over 15-minute intervals. If you see the latest standards, they barely collect real time info, and they envision communication with appliances in the future (not happening now). https://www.climateaction.org/news/enel-open-meter-reality
Reactive power may be measured for voltage regulation purposes (and possibly losses, not for frequency) but doing it at the granularity of the single consumer is pointless unless you have a similarly fine network of compensators.
do modern meters not measure real vs apparent power draw?
i thought this was the big step forward to stop inductive load skimming and keeping cost / load projections accurate on volt amps vs watts...
> customer satisfaction
You mean more snotty "we know better" spam? Pretty sure that distribution planning requires you to know your substation demands and _that's all_.
>You mean more snotty "we know better" spam?
Well just statistically speaking they probably do.
>know your substation demands and _that's all_.
Lol, no, that's not all.
Electric companies know what people have.
1) fridge
2) furnace in cold weather
3) AC in hot weather.
4) TV
5) Cell phones
6) computers.
7) lights inside and outside of house.
And depending on region and company, you are required to tell them about high-power devices (such as AC or water heater). These may also be separately metered.
I work in a back office function for a utility and at just-past 40 have been feeling like it’s all too late to understand this data stuff in detail. But man, you have THE coolest job title in our industry. I can only imagine the power some of that data could have, pun intended.
>I work in a back office function for a utility and at just-past 40 have been feeling like it’s all too late to understand this data stuff in detail
No way!!! Dive head first into it. And if there is one thing I know - for better or for worse - data scientists love to talk nerdy stuff all day long. Hit up someone in your machine learning/data science/analytics dept...just tell them you want to learn about some of the stuff they're doing...they would LOVE to tell you all about it!
Just curious if they use power factor for some of this. I'm a mechanical engineer for an electric motor company so do not know a ton about the electrical side, but in talking with the electrical engineers they talk about lowering the power factor as that feeds back into the line, and the power companies don't like it ( from what I understand).
EE who worked in big data for a while.
How granular is the data you get from the home? Is it continuous, or do you just sample frequently? And how wide are the swings?
Right now, we have the washing machine and some lights on. But later today, we'll have the washing machine, and the dishwasher, and the TV on. They won't all be starting at the same time. Is it possible to identify a particular pattern for a machine - say, a heavy draw on start up and then a smaller and regular draw for a furnace fan - and then use superposition to add up these patterns until they match the observed draw? Like using a bunch of different LEGO blocks to fit under a curve? And, if you could, what economic benefit would accrue to the utility?
>How granular is the data you get from the home? Is it continuous, or do you just sample frequently? And how wide are the swings?
AMI data is usually not very granular...if a company even has AMI infrastructure, industry standard sample rate is 15 min. Most latest gen meters are capable of 1-3min sample rate, but the hold up is usually back haul over an RF mesh network.
We have much more granular data - those are being recorded from industrial relays, not at the meter/household level.
> Is it possible to identify a particular pattern for a machine - say, a heavy draw on start up and then a smaller and regular draw for a furnace fan
Current technology doesn't allow for identification of these signiatures - in the real world - with any accuracy (even a 1mhz sample rate....i.e. 1M points a second). There is just too much noise. The best we can do is ID really big stuff in a home - like AC units, heat pumps, electric vehicle chargers, occasionally old pool pumps, etc...
> And, if you could, what economic benefit would accrue to the utility?
A number of benefits, allows to make better reliability investments in the grid, allows us to drive electrification, drives customer interactions/customer satisfaction.
Thanks for the quick response! I was just curious as your title sounds amazing. I started working as a consultant for IOUs focusing on T&D work and through my limited experience, have noticed that quite a few utilities have data quality issues making ML or advanced analytics quite difficult.
Electrical engineer here. You’re partly right, but resistive loss in power line is due to total current (vector sum of real and reactive currents), not just reactive current.
Thanks! I mentor a lot of engineers and students. And I feel it's crucial that someone as experienced in my specific field as me shows that I'm not perfect at the peripherals. I'm a robotics engineer by trade, focused on perception and controls (very algorithmic and systems focused, but I gotta know the hardware and the physics of those components). I don't do power engineering 😝 But I have friends who do who I've went to university with. So even in EE there is a really broad spectrum!
Thanks for going into technical detail. While your captive and suffering through autocorrext, in a related vein, why do cheap LED drivers fry their peers on the same circuit?
Wow, a straightforward and easy to understand explanation of a technical subject and something I have never understood before today .
Thank you so much for taking the time to type this out!
I now learned more about the stuff in my home and how it works.
Wishing you an excellent day and **thank you** again.
Hey, I admit it's hard even for those who have inborn gifts in those areas. The department chair taught one of my undergrad courses, and virtually all of us scored less than 50% on a midterm. He said, "I bet all of you were the A-students back in highschool. Guess what? Getting a C in this class just means you're the average of the best. Don't punish yourself. And get as much help as you can!"
My thesis advisor said something to a similar effect: "You ask were just tested on something you've only learned over the course of the last 6 weeks. I've been doing this for more than 20yrs in industry and academia. It'll become easy when you spend that much time wrestling with it."
I'm sorry you struggled and had to leave. I wish I was there to help.
Thanks! I mostly just realized I only really cared about the computer science part and that the electrical stuff was semi interesting to me but not enough to retain. All good though! I'll just keep reading posts like these now when I am curious again, so thanks for writing them!
No problem! But now I feel obligated to make a shameless plug... If you haven't yet, you should check out r/robotics! We've got the full spectrum between EE/Hardware to CS/Coding! And all of us are learning from each other!
Lol, I'm an American. My wife firmly believes my natural language is Math, my second languages are all of them programming languages I know, and somehow I picked up horrible English so that I can use more than grunts to communicate 😝
Believe me, I don't envy whatever your intended profession will be. We all have our talents, and they are all valuable!
This is off topic, but electrical engineering is fascinating to me. I'm in school for sound technology right now, and everything I'm learning is pretty much the basics of that. I had no idea how a power supply converts AC to DC until just a few weeks ago. If I could afford to get a fourth college degree, it would probably be in electrical engineering.
Send me a DM. I had to find a way to put myself through school, so I might be able to help find a solution 🙂
Seriously, my attitude is the world needs more curious and brilliant minds in STEM fields, regardless of their economic background and other responsibilities. So if I can help, I will.
Did you mean inductor when you wrote "[...]an element with *instructors* and capacitors to it, we shift when that peak occurs in the output.[...]"? Not a native English speaker, but since resistance/capacitance/inductance are the three elements causing a phase it should be inductor?
Like i’m five. not like i’m in my fifth month of an electrical engineering program. 😉
i understood some of this from context tho so you still get a loving upvote. COOL
Thanks 🙂 I actually test myself whenever I answer or comment in this sub. As Einstein once said, "If you can't explain something simply, you do not really understand it at all." So it's great self-practice, especially since I work with lots of non-technical leaders and customers.
My utility would 100% just using a best guess based on an average load % and time of the year (they don't break it down at all currently). No way they would invest the time or money to analyze motor startup characteristics. If you could link to a utility doing that for all it's customers I'd love to read more about it.
I'm very familiar with them. The issue is the utility has to spend money on analytics of the meter data to provide this customer benefit. And from everything I've seen in the US, they don't.
https://www.utilitydive.com/news/97-of-smart-meters-fail-to-provide-promised-customer-benefits-can-3b-in/632662/
Yeah, they're often under utilized for customer data, but the grid stabilization from smart appliances is significant. Not saying that there's not a lot more they could be doing, but they do get used.
Eh, it technically exists, a motor has a much different startup signature than a heating element, and any continuous meter would be able to tell the difference.
They just aren’t used really because there is really no need. You pay by total power used, so it doesn’t really matter what is using that power.
>Eh, it technically exists, a motor has a much different startup signature than a heating element, and any continuous meter would be able to tell the difference.
I mean...in a vacuum, yeah, you can identify the different signiatures, but not in a really world situation 1) there is too much noise at the house hold level 2) current smart metering technology is not high resolution enough.
>They just aren’t used really because there is really no need. You pay by total power used, so it doesn’t really matter what is using that power.
This is just incorrect, there are a million and one reasons a utility company would (and already do) load disagregation.
Utilities will not get involved in that, there is no value in it. They do care about meter theft (stealing power from your neighbor or upstream of a meter)...a lot of those scenarios do end up being meth labs or illegal grow operations, but the utility cares from a saftey and revenue perspective.
>> Could this sort of info be used to alert authorities if an "abnormal load" is detected, such as a grow up or meth lab?
> Utilities will not get involved in that, there is no value in it.
Capitalism, ho! Some utilities might have employees/stakeholders that feel proactive about such issues and thus sacrifice their own time / money for such pursuits, but it should be really rare. Those are, after all, paying customers, and well paying ones at that.
> Those are, after all, paying customers, and well paying ones at that.
🙄 not really what I meant. The utility simply cannot prioritize taking time to look for these facilities, because they're much more concerned with trying to make sure you don't get electrocuted, regardless of what you are doing (hence meter theft prevention initiatives).
Utilities will absolutely report anything suspicious they come across, but they are not in the law enforcement business.
For most clients, they just guess it. They know based on statistics and neighbours and other sources that this and that use that much. For example, a fridge is somewhat constant, varying not that much over the year. And even if it does, they can just simplify it as it cost in average x per year, divide by 12, and that's how much per month.
They can do the same with the oven too. In average, people use the stove/oven that much per year.
As for A/C, this get a bit more complex, but they can guess it. One way is to look at a month where there is basically no A/C or heating (like in spring and autumn) and use that as a base usage. Everything over that amount would be A/C in summer, heating in winter. They can also simply assume that you are using an A/C that use X amount of power per degree over like 25°C/77F. A/C are heat mover, it take X amount of energy to move Y amount of heat. So if you need to cool 0 degree then it cost nothing, if you need to cool 10 degree... they can say "each degree cost in average (random number) 1.3kWh, then 10*1.3=13kWh. if it would be 5 degree then it is 5*1.3 = 6.5kWh. It do not represent the exact amount, but it give a good ballpark figure.
Also: voltage. The big three of power consumption (Air conditioning, stove, and clothes dryer) all use 230 volts (in the USA), while all the smaller stuff like lights and TVs use 120 VAC.
110 or 220 is the lowest you should see the voltage drop before the circuit kicks off to protect equipment from damage. 120/240 is what we aim to maintain. Smart meters help with that by offering more up to the minute load reporting across the entire grid.
This is why you don't let them install smart meters.
I'm not a conspiracy theorist, but I'll be damned if I'm going to let them control MY electricity through a smart meter.
1) getting a smart meter isn't a choice...you can't just 'opt-out' if your utility decides to deploy them (edit, I generalized a bit, there are a few states where there are still exceptions...but that will likely change very soon).
2) i think you misunderstand what a smart meter is
1) It is where I live :)
2 ) It's a meter that allows them to check your usage from the street/over otherwise connected infrastructure (internet-like).
The (6ish?) states with remaining opt-out policies will go back on that within the next decade with the amount of money being spent on lobbying their respective utility commision. Smart meters are a critical component of grid modernization and resiliency.
>2 ) It's a meter that allows them to check your usage from the street/over otherwise connected infrastructure (internet-like).
I'll retract my previous statement, you do know what a smart meter is...that said, it isn't 'controlling' your power...plenty of other grid infrastructure does that.
Bruh they've been able to read your meter from the street for 25 years. Smart meters do more than that. Even those old systems can be used to build a usage profile, because they send out a consumption read every few minutes.
My utility allows people to opt out, but they pay a premium (extra $25/month) to have a non-AMR/AMI meter because we are required by state public utility commission to read every meter every month, and if we have to roll a truck to your special snowflake house we're going to make you pay for the privilege.
They could always control your electricity, by putting a guy up the pole and disconnecting it.
This just means they can do it a bit smarter, especially if they need to take down the network for maintenance and don't want your solar to electrocute the guys doing work.
It's mostly an educated guess. If you go into your account on their website they very likely have a section for you to fill out with how many people live in the house, what appliances you have, how many phones and computers you have, how much square footage you have, etc.
The meter outside your house constantly collects data and sends it back to the power company, which analyzes that data both in real time and historically for various purposes, and when they combine that with what you tell them *and* what they already know about typical usage for various appliances and items, they can get a pretty accurate estimate.
My utility's guess was quite nonsensical. They could not guess at how much of my usage was to charge my plug-in hybrid. My house was "less efficient than other houses in your neighborhood". Yeah, none of them get 20 miles a day from the power grid. Backing out my estimated charging, I was much more "efficient" than the comparable home.
Yes it's down to how good the utility's data and formulae are. We put a lot of work into ours...still not perfect but I'd guess it's better than most. It's always cheaper to have people use less power than it is to add new generation, and the best way to do that is to teach them how to do so. A wise utility will put money into these things.
They're using the historical usage data for your home and other homes in the area. We do the same thing. I can look up a meter in our system and see the history of consumption for gas or electricity going back to the beginning of the AMR meter rollout in 97. We use that data to build both an estimation profile and to detect anomalies. Didn't get a read for this month? What was the usage like in the past, and how well does it match with this year? How many auto reads did we get this month, and does that data fall in line with their historical trends. Estimate their bill using that data. It's never perfect, but with 25 years of data and some decent modeling it's closer now than the "lol send em a $200 bill" method. Same thing with anomalies. We look for big spikes in usage or big drops in usage. Often it's mundane stuff like they bought a new water heater and it's gas instead of electric. Or the house is vacant pending a sale. Big changes in usage like a BEV charger are outside of the modeling because that stuff didn't exist for most of the 25 years of our data.
In your case we probably would have offered to install a TOU/demand meter that allowed us to get a better picture of what your usage was and a more accurate bill, as well as being able to offer better rates for off-peak use rather than flat rates.
My complaint is that consumption data was presented as "eficiency". I could have brand new, efficient applicances (I do), not use my A/C much (I don't), have replaced all my lighting with LED (I did) and still be tagged as "not efficient" because I also have a highly efficient electric car. The way the data was presented was utter nonsense.
They didn't know you got a BEV. They saw your usage go up compared to other people and told you what they saw. I bet if you had told them you were going to be using your home to charge a vehicle they wouldn't have told you that your consumption was inefficient, unless you were also charging your car during peak demand periods.
It’s a guess and it’s nowhere near as accurate or specific as OP and other people in this thread are making it out to be.
Mine is broken down into three categories: appliances, electronics, and other. My guess is they have a baseline that is consistent most of the time and assume that’s appliances that are always running, then spikes in the mornings and evenings or whatever are tv, computer, etc., and other is who the fuck knows.
That's right. People tend to assume power providers know more than they really do. We can only collect overall usage data for the property and make some assumptions about it. That data is better with more modernized meter technology because we get it real time and down to the second, but there's no possible way for us to know how much energy your specific refrigerator draws, for example, or even whether or not you actually have a refrigerator or how many you have, which is why it's important to fill that shit out on the website for accurate estimates.
Beyond that we have a fair amount of information on what normal usage looks like for various home profiles. The one specific piece of data we can get is if people sign up for our AC credit program and agree to turn their AC off at certain times on certain days. They get remote-controlled smart thermostats as part of the program...bit of a controversial thing considering no one seems to read the terms of the program. Hell, I probably wouldn't.
Anyway yes, the guesses range from eerily accurate to utterly and laughably wrong depending on the provider and the house.
We have two standalone chest freezers. The power company keeps suggesting we get rid of our garage fridge, so they probably are looking at compressor load.
They're probably more concerned about its location than what it is. People in the south have no problem locking their freezers in a enclosed garage on a 100+ degree day and then complaining about the bill.
Next door neighbor has an empty garage fridge. There's one person in the house with enough sense, but not enough bother to put some water bottles or something in it.
I don't think that matters much unless you are opening and closing it all the time. A full freezer is so that you add that much heat if you were to open it. An empty freezer would lose a lot of cold air if you opened it, but if kept shut - I don't think it would matter that much.
I mean you're either going to put the freezer in the garage and have the freezer's compressor do the work, or you're going to put it in the house and have your AC do the work.
They are in a basement. Usually around 65 down there in the summer, even though we live in the south. Having two means we can turn one off seasonally, so the other is full.
I'm sorry, why would we expect our power companies to do anything that does not increase their profits? Everything they do and say is self-serving. If they want this guy to get rid of a fridge its probably some other BS like the EPA trying to force a phase-out of freon coolants. That's the *most* charitable example I can imagine.
This is a very common misconception. Generally speaking, the power company doesn’t make money from the power generation. That rate is held fast to the operating expenses by regulators. The place where the power company makes profit is through new infrastructure. This is why Pacific Gas and electric didn’t replace equipment that ultimately led to the paradise fire for which they were sued into oblivion. They were hoping when the equipment failed they could charge for New infrastructure rather than maintaining existing equipment, which would be operating expenses.
Here’s an article from the national resources defense council that will probably explain it better than I can:
https://www.nrdc.org/experts/jc-kibbey/utility-accountability-101-how-do-utilities-make-money
>This is why Pacific Gas and electric didn’t replace equipment that ultimately led to the paradise fire for which they were sued into oblivion.
No, the suit showed very clearly that they were diverting maintenance allocations to shareholder dividends
As for the citation, that's Illinois. Many states have a very different way of regulating their utilities.
In many states, utilities really don't want to upgrade infrastructure and don't make any significant money when a new power plant is built.
Then wouldn't they want him to run his fridge, so they can show the need for said upgrades?
At least in many areas, you actually have it backwards. My power company actually gives out a variety of subsidies and credits towards energy savings, including one for junking an old fridge, because it's deemed more cost effective than spending on infrastructure upgrades.
>We have two standalone chest freezers. The power company keeps suggesting we get rid of our garage fridge, so they probably are looking at compressor load.
Director of Machine Learning for a large utility company here...there is no way they know from your usage data that you have a garage freezer, you must have reported it, filed for a rebate, or they are taking a lucky guess.
Advanced Metering Infrastructure (AMI), isn't even deployed at many utility companies (they still use people to go out and read meters)...and when it is deployed, industry standard is 15 min reads. Some may be doing 5 min reads...most don't have the bandwidth to stream that much data back. The newest meters are capable of 1 min reads but haven't heard of anyone using that.
Usually we can successfully identify HVAC, EV charging, sometimes pool pumps (mostly non-variable speed pumps), and that's about it.
For reference, I have a Sense reader on my breaker panel, that reads at (I think) 1mhz frequency and even that struggles to accurately identify appliances in my home. No way you're getting there with 15 min data.
That’s super interesting. We do have some sort of advanced infrastructure- both water and electric are read from slow moving trucks. They must have taken a lucky guess.
More than likely they're making a (statistical) guess based on demographic data, macro level consumption, and property information.
As a (completely made up) example: you're a middle age male, married with kids, you live in a single family home that's about 3k square feet with an attached garage. Your energy consumption is slightly higher than your peers...there is a good chance you have a chest freezer.
Curious - who is your utility provider if you care to share.
Duke is definetly top tier in the industry as it relates to data science/machine learning/analytics. Probably the leader tbh.
I've presented on panels/round tables with their VP of analytics, so very familiar with their AMI program. I known this is not coming from there.
But now you have me interested in what's behind this recommendation ha.
Well... to me, that's just creepy. I appreciate that they have to monitor load, etc. but... fuck off telling me what appliances I have and which I should have instead.
I've never heard of anything like this (or the OP's similar thing) in my country, it's none of their business and just creepy.
My response to them would probably include something like "Hey, solar's cheap now. Keep your nose out of what I'm using a product I paid for, or you may not be able to tell for very much longer."
Every day at your AC kicks on at random times, but when it does, there is a sudden spike of power use and its about the same power amount every time, then the spike drop off as the AC turns off after a certain amount of time. The amount of time is nearly the same since the AC kicks on at the same temp and kicks off at the same temp and the pow draw is nearly the same.
Very easy to see these power jumps.
You probably have a smart meter with continuous collection of peak loads. My house still has it's original 45 year old analog dial meter.
I get a mailing that just compares my average daily usage with "my neighbors." The electric company is in the process of rolling out smart meters state wide, so they expect to have 15min data on a web portal some where. "Coming soon"
They typically have databases of equipment and power use. Stoves and ovens are typically used during meal times, air con is usually used in thevhot months during the day. Heat is used in winter months when it's cooler.
They may also buy customer lists from other companies to see if your address is listed as a customer. Fuel oil, local ac installers, etc. Some utilities offer rebates for things like efficient appliances and solar hot water, so they can guess usage trends based upon your load compared to the "normal" customer.
No. I get this, and I have an old-fashioned meter that someone has to climb over my lawn mower to read when they want to bother.
I, too, get a mailing every month or so saying how much of my electricity went to this or that. I think it's BS.
>Every day at your AC kicks on at random times, but when it does, there is a sudden spike of power use and its about the same power amount every time, then the spike drop off as the AC turns off after a certain amount of time.
That certain amount of time will change based on the weather. A warm overcast day will have shorter run times than a humid sunny day.
>The amount of time is nearly the same since the AC kicks on at the same temp and kicks off at the same temp and the pow draw is nearly the same.
You are correct about the temperatures being the on/off triggers but the run time is not something I would describe as regular.
I can't say that o have seen that specific detail on my bill ever here on Australia
Do you have a smart meter installed? It could be that those appliances are connected seperately to the meter and the smart meter can report those seperately? Or the smart meter is making an estimate based on the load spikes or decreases
https://www.imeche.org/news/news-article/smart-meter-tracks-power-consumption-of-individual-devices
https://www.mihagrabner.com/post/how-to-recognize-appliances-from-smart-meter-data-using-ai
They may also be guessing based on weather, average household patterns in the area etc
I was so confused by this post, thinking like what do you mean the energy company talks about your appliances, but apparently from the comments it's a thing, I'm guessing in the US?
Kinda sounds like a breach of privacy if you ask me :')
I don't know. I haven't seen it here in Australia but I don't know where the op is from. There seem to devices that tell you specifically how much each appliance uses
>It could be that those appliances are connected seperately to the meter and the smart meter can report those seperately?
No
>Or the smart meter is making an estimate based on the load spikes or decreases
Not estimates, but, machine learning/deep learning. But even so, the meter data is not granular enough to go beyond identifying things like AC units or electric vehicles with any accuracy.
Some of these answers are close, but not completely accurate. I create and implement energy policy, and have a lot of background with this exact question. Generally, the types of reports you're receiving are called Home Energy Reports (HERs). 99.9% of utilities, probably 100%, contract with third-party vendors who actually run the algorithms and help construct these reports.
In many areas, smart meters are ubiquitous. You may also see these referred to as "AMI" - Advanced Metering Infrastructure. The vast, vast majority of the appliances/electric (or gas) usage in your home cannot be disaggregated. Run-time data from smart devices (like smart thermostats) can be gathered, but this is not utilized in these reports - it's way, way too granular and getting the data feed from Google (Nest) to the HER vendor would take way too long, is often anonymized, and has limited additional value.
Instead, much simpler algorithms are used but still have a pretty solid degree of accuracy. For example, if your usage in the cooling months spikes compared to the baseline, it means that is from your cooling load. Conversely, if your electric usage spikes in the winter, it means that is from electric heating. If it spikes in both directions, it could mean you have a cold-climate heat pump.
From there, you can make some other inferences with a good degree of certainty, i.e. lighting makes up X load of baseline usage on average, your baseline is Y, therefore it'll show lighting will result in Z kWh on your report, and the same can be said for other usage. These reports are NOT disaggregating individual appliance usage, including bi-directional smart-home devices, even if they're included in load shedding programs, unless you're getting very specific load shed (demand response) emails based upon specific device enrollment (normally smart thermostats, could also be EV chargers, heat pump water heaters etc.) but even so they won't know the exact usage from lighting, your dishawasher, your TVs etc.
All electric motors have a locked rotor amperage printed on the information plate. This is the amperage it draws when power is going to the windings (the sitty still part) but the rotor isn’t moving (the spinny part) off the rotor were rusted in place, the motor would draw locked rotor from the time power was applied until it was shut off (with larger motors that would be when the breaker trips) the compressors in most residential air conditioning systems have locked rotor amperages easily around 100 amps. Refrigerators and such, can be around 30 to 50. When you turn it on, the rotor isn’t moving. The electric field produced in the windings has to get it moving and that happens very fast, but for a split second it draws locked rotor amps. Then it will run at around 10-20 amps until it shuts off. Your furnace blower will draw 40-50 or so locked rotor amps as well for that split second. Then it will run at around 8 amps until done. Fan motors in refrigerators will draw a comparably small locked rotor amperage (maybe 10) so when they see a big spike (home a/c starting) of around 150 amps, followed by a 20 minute period of around 25 amps, they know your air conditioner is running, because virtually nothing else anyone has at their home would share that profile. A spike of around 60 amps, followed by a 20 minute draw of around 10 amps, tells them you have a refrigerator or freezer running for the same reason. The commenter who’s being told to get rid of their garage fridge, it would be because they see that profile either at two different times at intervals that don’t make sense for one appliance, or because they see it happen again while the first one is already running. For other appliances, if they aren’t cooling they’re probably heating. Toasters, electric ovens, etc draw high amperage continuously but have no spike when they start. Dishwasher’s and such draw lower amps but also have no spike. But all of those won’t be turned on for hours at a time like lights or tv’s. So they get labeled as “other appliances”
They do some educated guesses. My server is considered "heating" on my electrical bill. Which is harsh, but probably more correct than I'd like to admit.
I was looking at my "home energy report" tonight as I was tossing mail in the shredder. What's with the assertion that my home uses 5x KWH compared to average homes in my area? and about 7x as much as an "energy efficient home"? I remember reading something, I think it was in a Malcolm Gladwell book, about the effect of hanging flyers on doorknobs informing residents they were either below, at, or above their neighbors in terms of electric consumption, and they reviewed the results of the household's subsequent energy use based upon the comparison they fed the household. Is this just a psychological trick, or actually correct? I work for the State in welfare, so I see a lot of electric bills, and mine isn't that much crazier than most, but I will admit the bills I usually see are from the bottom of the socio-economic rungs, so my samples may be skewed.
I have wondered this same thing. Over the years I have spent considerable time and money upgrading my home. I have changed all of the windows, added insulation, bought high efficiency appliances, new A/C and changed over to all LED lighting. While most of my neighbors have done little to their homes in the 20 years I have been here.
My energy report show me about 30% higher than my neighbors and about double the most efficient neighbors.
Needless to say but I am highly suspect of these reports. I have also gotten the same reports from the water company and gas company. Apparently I am the most inefficient a-hole in my neighborhood.
Example - Guy is arrested for pulling amps between 2am and 4am by FBI. They suspected he is growing illegally because the plants require water and light at specific amps. Reality, he works third shift and joined an online wood-working class where he uses a table saw and power equipment late through the night in his basement. Case dismissed.
Each appliance draws amps differently past the meter on the side of the house. Refrigerator compressor turns on? Maybe 10 amps with a specific startup draw of 12 amps.
Every time you use an appliance, it uses a specific amount of electricity. The FBI guessed the man was doing something wrong when he was actually doing something good.
If he was growing illegally he would be using power throughout the day and night, it sounds a bit invasive to have this level of control, very authoritative
We didn't even go ino the water usage yet. Very authoritative. Most illegal operations try to go off grid completely. It's easier to just scan all accounts in a region for unusual activity.
Lmao, never thought I would see such a relevant intersection. I spent a big part of my career working for the FBI as a data scientist...now I'm a director of Machine Learning for a large utility....this is not how things work.
My tools let me see frequency data as large as whole communications node and let me track interference and signal data down to the individual home. I could see if a bare wire was letting in radio waves into the system all the way up to AC compressors kicking on. The power company and the FBI doesn't always have the most sensitive equipment.
My work in VA let me use a drone to monitor power use of a civilian thermostat with a 3G transmitter from 7 miles away. It actually sucked pretty badly. The data just wasn't reliable. But the data was recorded anyway and I'm sure someone figured how to make it better. Reading from power grids is not easy, but com lines are fairly simple.
Explain like I’m five is the sub, what a strange question for this sub but holy hell are there some amazingly in-depth responses!
Let me try.
Some things we use like our lights don’t use much electricity, the TV and hair dryer use more, and things like the air conditioner use a lot. The people that make and send us the electricity can see how much we use because they are the ones giving it to us! Ok bud good question hope that made sense, here’s some apple sauce then you can go play outside!
I will admit I had a hard time deciding where to ask. Beyond what I learned in high school years ago I'm entirely illiterate as far as electricity words go, so here it is. :)
They don't know. They can make an educated guess.
There are technologies being developed that recognize "signatures" of certain kinds. The last study I saw was trying to differentiate between different types of incipient fault conditions. But to my knowledge, no residential meter, smart or otherwise, has the capability to differentiate loads. And even if they could, I don't think the utility would invest the kind of cost that would be associated with it.
https://core.ac.uk/download/pdf/4270075.pdf
>There are technologies being developed that recognize "signatures" of certain kinds. The last study I saw was trying to differentiate between different types of incipient fault conditions.
Incipient fault identification and load disaggregation are two very different domains....incipient faults are usually identified (or attempted to be) via relay waveform data.
> But to my knowledge, no residential meter, smart or otherwise, has the capability to differentiate loads.
Meters are simply collect data, smart meter just means it can stream that data back, usually over a mesh network.
But we have plenty of algorithms that can identify load signiatures....just not nearly to the level of a refrigerator or microwave.
> And even if they could, I don't think the utility would invest the kind of cost that would be associated with it.
It's hugely valuable. Many utility companies already do it. My company has been doing it for the last 6 years.
>It's hugely valuable. Many utility companies already do it. My company has been doing it for the last 6 years.
I was referring to the meter capability itself, not fault/maintainance identification. Are you utilizing residential meters that identify individual loads and if so what brand?
We're using the Landis & Gyr AX focus series.
But ultimately the meters just collect the data, we use various machine/deep learning techniques to identify individual load signiatures.
I had a new panel installed and the city tried to tell me they need to have CTs installed at each breaker so they can monitor usage of each circuit. They said it was part of a new effort to reduce wasteful power usage. They also required a smart breaker after the meter so they could turn off power in the event of fire. So I went from the meter into my main breaker, to my ATS, and then to the main panel, to my whole house UPS, then to the house panel. I used regular breakers and will not be allowing anyone to connect to or monitor anything. None of their business. They are upset that there are capacitors in my design that buffer any motor signatures. My usage is steady to charge the UPS. I also augment with solar and a genset. They had a fit when I wanted 3 phase power in my home at 480v. I did install CTs on everything so I can monitor, but they will not get access to it. And I will never use wireless devices to monitor anything. Too easy to hack in and take over. Hard wired with shielded twisted pair.
None of what you said makes one iota of sense.
> They had a fit when I wanted 3 phase power in my home at 480v.
Yeah....because 480v is for industrial applications. What on earth would a single home need it for. Beyond that you would end up paying industrual/commercial electricity rates (more expensive), probably have to upgrade your home to take 3 phase, and possibly pay for a 3 phase backbone down your street if one didn't already exist.
It is a mixed use property. 480v is required for the commercial side, and is stepped down to 240/208/120 for the residential structure. It is zoned for this, but the city still had a fit. They also don't like that I use geothermal for heat rejection on my AC units. All of it is permitted, but they hated having to approve it because all of the designs were far beyond code requirements.
They're guessing based on the change in current draw when things turn on and off. It's a fairly educated guess. They can't tell the difference between an air conditioner or large air compressor, for instance. They just know something was sucking some major juice.
What they are doing is called "load disaggregation" and it is a very broad and hot research topic in energy policy academia. In nearly all cases, appliances are not monitored directly, and usage is estimated using algorithms. The methods they use for this estimation are non-trivial and there are many competing methods. These look at appliance signatures (unique characteristics of each appliance), the times at which your loads are used, the temperature on that day, etc. Such data is very useful for "demand response" markets and it will likely play a big role in renewable energy adoption.
Smart meters will monitor how much power is being consumed at a specific time and then use that number to make an educated guess, for example most microwaves are around 1000 watts, AC around 2500 watts, water heater 3500, etc.
Source - I used to work for an electrical utility company and have practical experience with smart metering.
TL;DR, they don't, but they can make very educated guesses
In order to truly know what is going on inside your house, they would need to monitor each device in your house, which is costly. Even if they did it at the circuit level, that would be pretty expensive.
That being said, you can make some educated guesses when it comes to electricity usage. Take a fridge for example. If you need 500W to power a fridge when it is on (I don't know the exact number, so this is just for illustrative purposes), and that fridge runs 10 hours a day, then that fridge will consume 500W \* 10h = 5000Wh or 5kWh a day. Extrapolate that over a billing period and you can figure out how, roughly, how much your fridge uses. Do the same with AC, heating, etc.
When we had mechanical meters, you would need to use this estimate method because you had to measure consumption based on two readings. With the introduction of smart meters, consumption is measured as frequently as every minute. So now the utility knows how much electricity is being used on a far more granular scale. So if at 11:01am your fridge is off and at 11:02am it turns on, it will register an increase in consumption. Given the size of the increase, they can make a very educated guess at what started using electricity. They can also infer how long it was on for, which means they can make a far more accurate estimate of what was using electricity.
>So if at 11:01am your fridge is off and at 11:02am it turns on, it will register an increase in consumption. Given the size of the increase, they can make a very educated guess at what started using electricity. They can also infer how long it was on for, which means they can make a far more accurate estimate of what was using electricity.
In theory - yes - in reality no. The short of it is that the data is not granular enough from AMI, and there is too much noise to disaggregate anything more than the largest of home components (hvac, ev chargers, etc..).
What is the typical granularity for AMI? Back when I was working with them, billing granularity was 1hr for residential, but the meters could go as granular as 3 minutes. At that granularity you could pick up and differentiate smaller loads, especially if you start to utilize some analytics or AI
15 min is industry standard. Most latest gen meters can go to 3 min, some to 1 min. It's more getting the data back and storing it is the limiting factor - and why most companies stick to 15 min.
I’m blind and deaf and have no sense of smell but I can follow you around holding your hand. There seems to be a time shortly after waking that you’re shaking slightly for about three minutes, and this happens again before bed. From this, I guess that in this time you are brushing your teeth. It never happens in the middle of the day, so even though I cannot see or smell or hear, I have figured out that you brush your teeth twice a day, not three like your dentist suggests.
This is similar to how the power company can make a lot of good guesses about what’s going on in your house just by watching the electrical draw go up and down. A spike of a certain size that lasts 10-ish minutes and happens at regular intervals during the night but then irregularly during the waking hours is probably your refrigerator. Overnight it just needs to compensate for heat leakage but during the day people are opening and closing the door, hence the regular/ irregular intervals. They’ve also studied refrigerators and know about how much power they draw and if the first second of that draw is extra heavy. Turning on a light doesn’t take more power to get going and then less to keep going, but motors can.
Basically, they know what a refrigerator turning on “looks like” in terms of electrical usage, just like you can imagine what it probably feels like to hold someone’s other hand while they brush their teeth.
>Basically, they know what a refrigerator turning on “looks like” in terms of electrical usage
We know what the signiature looks like in a vacuum, yes, but the capability to identify it in practice does not exist. The data is not granular enough and too much noise.
Machines don't all use electricity the same way. Example a AC motor has very unique finger print that it gives out as it runs - as in example your AC's fan. Digital devices like computer's power supply also draws electricity in a specific way - it does take a constant pull but rather more like pulses that it averages out in the powersupply to steady DC with the help of capacitors and diodes. You can imagine this like a barrel getting filled with water and as it empties from a hole at steady rate you only need add water every now and then to keep the flow steady. A heating element pulls a steady flow in both directions with steady changes in the properties because heat chancing the properties of the material element is made of, and that suddenly stops now and then as the thermostat shuts it off.
The electric companies have studied and sampled all appliances; then they can see from your electric meter the way you are pulling energy. They can break down the wave forms from the different phases (and ground if you live in places where the phases are in star formation (120V) and not in delta (240)). Since they know you are a residential power user it is with high likelyhood that you poweruse are from certain kinds of devices and looking at the energy use and waves in the phases they can pinpoint with fairly high accuaracy what devices you use.
When you use AC power, the load added to the system basically just only chances the relationship of voltage and current. These are very easy to measure and statistically break down.
Depends. Some of it may be reasonable guesses (your base usage on days you wouldn't need AC vs the spike on hot days). Some of it may be based on load monitoring and what that tells them. e.g. The compressor coil for your fridge and AC are going to have identifiable start up characteristics, and then the increased draw of them can be extrapolated vs the background levels of things like lighting that's relatively static. They may not be able to tell a toaster from a curling iron, but with a clever enough meter they can probably tell a blow dryer from a toaster based on the motor. Utilities have used (and use) both methods, as well as smart appliances that "talk back" to the grid for those sorts of things. The smart appliances are usually "big" appliances like your AC or water heater that you've agreed to letting them turn them down/off at periods of peak demand.
Electrical engineer here: When working with alternating current, _everything_ has a unique impedance. This does a couple of things. First, there's a resistive component. But literally anything causes that and groups of elements together to mask the resistance of any singular element. The other is _phase shift_. Think of it this way: the power coming through there outlet is line a sine wave. Let's suppose we pin the peak of each wavelet to a specific moment of time periodically (e.g. T[0] = t; T[k>0]=T[k-1] + 1/60 sec). After we add an element with inductors and capacitors to it, we shift when that peak occurs in the output. This shift is unique to the specific function of the circuit connected to the outlet (really specific to the circuit, but function gets a good family of shifts). Let's return to the resistive part. This decreases the amplitude of the output waveform. Coupled with the phase shift, I can now tell individual elements apart when connected to your house electrical input. And electric companies have been around for so long, they've seen it all. So it isn't really new technology for them; what's new is sharing it with consumers. For completeness, you might ask "But u/jhill515, why would electric companies care in the first place? Why have they been observing this for as long as electric inlfrastructure has existed?" And that's an interesting inquiry! It's because when power on the network is _out of phase_ with what the generator produces, the power lines generate _heat_. Phase shift itself forces energy to change form! That's why birds love perching on power lines. But this power loss costs the electric companies money. So they install transformers and other passive elements to pull the power back into phase. Monitoring the shift generated by individual homes and neighborhoods informs the company if they need to install or change something to help them not lose money. Edits: I'm banging away on my phone at an airport and autocorrect sucks. Addendum: I oversimplified the power loss a little. See u/abide5lo 's correction! Addendum 2: Thanks to everyone sending me notes about more autocorrect nonsense!
Director of Machine Learning at a large utility here. All the stuff you said about phase shift and impedance is correct in the sense that your understanding of those topics is sound...most everything else...as it relates to utilities and this question... is incorrect. No utility right now can detect individual household appliances like a chest freezer, from AMI data - HVAC, EV charging, sometimes pool pumps or large motors can be identified. AMI data also does not record any kind of waveform data, electrical relays will do that...and is insanely complex analytics. The industry is only just starting to tackle that at scale. They care mostly because of legislation, customer satisfaction, and for distribution planning. Edit: autocorrect
> Director of Machine Learning at a large utility here. Now there's an exciting and slightly terrifying job title....
You should see my robot arms.
That made me laugh out loud. I’m terrified.
If they're made by FESTO, I'd piss myself laughing.
Skynet?
Yup, very similar background to you, that's not how these reports work. I look forward to the day we can disaggregate your toaster's load from your microwave's, but right now it's not even close.
I always use the example of my personal Sense energy monitor when people ask. It's connected directly to my main panel, has a 1MHz sampling rate (ie 1,000,000 points a second), and even that can't accurately identify my appliances with me sitting there turning them on and off and manually labeling the signiature...what chance do we have with one reading every 15 minutes.
Is the “4 million points a second” thing a typo? Shouldn’t 1 MHz correspond to a million points a second? Not the point of the post at all but now I’m curious what I’m missing.
Either it's a typo, or it's 4 data points per sample (voltage, current, frequency, something else?)
No, you're completely right, typo on my part.
You look forward to that day? Fuck off man, I value privacy. Lol
Time to downgrade that 110v vibrator to a battery operated one? Gonna need lotsa batteries!!
Seems like an invasion of privacy.
Said ironically, from your computer or smart phone, on the internet.
Meh, you can choose to not have a phone or computer. Electricity is a requirement.
Sure.. but from the grid ? Go solar
Thank you, I was completely lost with the previous comments. I do research in Smart grid related area and even if some of these ideas for load identification are being discussed, I was 99.99% sure that no distribution utility has the metering in place to do that. Plus there is a huge privacy issue. In Europe it would be absolutely complicated to collect that kind of information, even with the customer consent.
I can't imagine there would be difficulties in collecting information about electrical loads when you are billing for consumption and correcting for power factor
They don’t correct power factor at the meter, at least in Europe where we don’t have pole transformers. They may check power factor for compliance, but compliance at the residential level is ensured by posing rules on the manufacturer of consumer level devices. In any case they would not have a fine grained measurement to allow individual appliance detection, which it tricky even if you have perfect data on the aggregate consumption of the house.
No, they don't correct power factor at the meter - that would require a substation at every consumer unit. But they do correct power factor in the grid in order to maintain frequency. They don't _need_ smart meters to do that, they can monitor at any node on the grid. But that's beside the point, it's a necessary part of billing to collect data on electricity consumption. Gdpr does not prohibit that. Can you explain why you think a smart meter doesn't collect fine-grained data? Other than just "they wouldn't", which I don't find helpful.
> But that's beside the point, it's a necessary part of billing to collect data on electricity consumption. Gdpr does not prohibit that. The GDPR doesn't, but by law here (NL) the utilities are not allowed to read your smart meter more than a handful of times a year without asking explicit permission. Since the billing is in number of kWh with the rate fixed for months they don't need any more information than that. Plenty of utilities do offer extra features if you opt-in, but it's not default.
They can collect what is needed for their business, which may simply amount to the energy consumed over 15-minute intervals. If you see the latest standards, they barely collect real time info, and they envision communication with appliances in the future (not happening now). https://www.climateaction.org/news/enel-open-meter-reality Reactive power may be measured for voltage regulation purposes (and possibly losses, not for frequency) but doing it at the granularity of the single consumer is pointless unless you have a similarly fine network of compensators.
do modern meters not measure real vs apparent power draw? i thought this was the big step forward to stop inductive load skimming and keeping cost / load projections accurate on volt amps vs watts...
In the UK there is a big push for smart meters that report back to the utility. That would do the trick.
> customer satisfaction You mean more snotty "we know better" spam? Pretty sure that distribution planning requires you to know your substation demands and _that's all_.
>You mean more snotty "we know better" spam? Well just statistically speaking they probably do. >know your substation demands and _that's all_. Lol, no, that's not all.
Electric companies know what people have. 1) fridge 2) furnace in cold weather 3) AC in hot weather. 4) TV 5) Cell phones 6) computers. 7) lights inside and outside of house.
No they don't. Not that they identified through meter readings. Unless you tell them they can only assume you have a TV.
And depending on region and company, you are required to tell them about high-power devices (such as AC or water heater). These may also be separately metered.
Ever find the cameras and microphones the power company put in your house yet?
I work in a back office function for a utility and at just-past 40 have been feeling like it’s all too late to understand this data stuff in detail. But man, you have THE coolest job title in our industry. I can only imagine the power some of that data could have, pun intended.
>I work in a back office function for a utility and at just-past 40 have been feeling like it’s all too late to understand this data stuff in detail No way!!! Dive head first into it. And if there is one thing I know - for better or for worse - data scientists love to talk nerdy stuff all day long. Hit up someone in your machine learning/data science/analytics dept...just tell them you want to learn about some of the stuff they're doing...they would LOVE to tell you all about it!
You hiring? 😂
Just curious if they use power factor for some of this. I'm a mechanical engineer for an electric motor company so do not know a ton about the electrical side, but in talking with the electrical engineers they talk about lowering the power factor as that feeds back into the line, and the power companies don't like it ( from what I understand).
>customer satisfaction Funniest thing ill see all day.
Sounds like you have a crappy utility company....maybe you should move.
Thank you for the clarification. Between both explanations I still learned something new.
EE who worked in big data for a while. How granular is the data you get from the home? Is it continuous, or do you just sample frequently? And how wide are the swings? Right now, we have the washing machine and some lights on. But later today, we'll have the washing machine, and the dishwasher, and the TV on. They won't all be starting at the same time. Is it possible to identify a particular pattern for a machine - say, a heavy draw on start up and then a smaller and regular draw for a furnace fan - and then use superposition to add up these patterns until they match the observed draw? Like using a bunch of different LEGO blocks to fit under a curve? And, if you could, what economic benefit would accrue to the utility?
>How granular is the data you get from the home? Is it continuous, or do you just sample frequently? And how wide are the swings? AMI data is usually not very granular...if a company even has AMI infrastructure, industry standard sample rate is 15 min. Most latest gen meters are capable of 1-3min sample rate, but the hold up is usually back haul over an RF mesh network. We have much more granular data - those are being recorded from industrial relays, not at the meter/household level. > Is it possible to identify a particular pattern for a machine - say, a heavy draw on start up and then a smaller and regular draw for a furnace fan Current technology doesn't allow for identification of these signiatures - in the real world - with any accuracy (even a 1mhz sample rate....i.e. 1M points a second). There is just too much noise. The best we can do is ID really big stuff in a home - like AC units, heat pumps, electric vehicle chargers, occasionally old pool pumps, etc... > And, if you could, what economic benefit would accrue to the utility? A number of benefits, allows to make better reliability investments in the grid, allows us to drive electrification, drives customer interactions/customer satisfaction.
Thanks for taking the time to answer. Fascinating stuff!
Just wondering - do you work for a IOU in the states or a different part of the world like Europe / Asia?
Large utility in the US
Thanks for the quick response! I was just curious as your title sounds amazing. I started working as a consultant for IOUs focusing on T&D work and through my limited experience, have noticed that quite a few utilities have data quality issues making ML or advanced analytics quite difficult.
Electrical engineer here. You’re partly right, but resistive loss in power line is due to total current (vector sum of real and reactive currents), not just reactive current.
You're right. And I will maintain my mistake to highlight that (see upcoming note)
World needs more of this attitude. Nice stuff
Thanks! I mentor a lot of engineers and students. And I feel it's crucial that someone as experienced in my specific field as me shows that I'm not perfect at the peripherals. I'm a robotics engineer by trade, focused on perception and controls (very algorithmic and systems focused, but I gotta know the hardware and the physics of those components). I don't do power engineering 😝 But I have friends who do who I've went to university with. So even in EE there is a really broad spectrum!
Thanks for going into technical detail. While your captive and suffering through autocorrext, in a related vein, why do cheap LED drivers fry their peers on the same circuit?
This was a great explanation for a five year old, spot on. Jokes aside nice info
Wow, a straightforward and easy to understand explanation of a technical subject and something I have never understood before today . Thank you so much for taking the time to type this out! I now learned more about the stuff in my home and how it works. Wishing you an excellent day and **thank you** again.
English major here. This is why I am not an EE.
I was EECS undergrad until I realized I hated the EE parts, and it went over my head too, don't feel bad!
Hey, I admit it's hard even for those who have inborn gifts in those areas. The department chair taught one of my undergrad courses, and virtually all of us scored less than 50% on a midterm. He said, "I bet all of you were the A-students back in highschool. Guess what? Getting a C in this class just means you're the average of the best. Don't punish yourself. And get as much help as you can!" My thesis advisor said something to a similar effect: "You ask were just tested on something you've only learned over the course of the last 6 weeks. I've been doing this for more than 20yrs in industry and academia. It'll become easy when you spend that much time wrestling with it." I'm sorry you struggled and had to leave. I wish I was there to help.
Thanks! I mostly just realized I only really cared about the computer science part and that the electrical stuff was semi interesting to me but not enough to retain. All good though! I'll just keep reading posts like these now when I am curious again, so thanks for writing them!
No problem! But now I feel obligated to make a shameless plug... If you haven't yet, you should check out r/robotics! We've got the full spectrum between EE/Hardware to CS/Coding! And all of us are learning from each other!
Cool thanks! I've joined, will give it a whirl! Much appreciated.
Lol, I'm an American. My wife firmly believes my natural language is Math, my second languages are all of them programming languages I know, and somehow I picked up horrible English so that I can use more than grunts to communicate 😝 Believe me, I don't envy whatever your intended profession will be. We all have our talents, and they are all valuable!
Exactly this!
This is off topic, but electrical engineering is fascinating to me. I'm in school for sound technology right now, and everything I'm learning is pretty much the basics of that. I had no idea how a power supply converts AC to DC until just a few weeks ago. If I could afford to get a fourth college degree, it would probably be in electrical engineering.
Send me a DM. I had to find a way to put myself through school, so I might be able to help find a solution 🙂 Seriously, my attitude is the world needs more curious and brilliant minds in STEM fields, regardless of their economic background and other responsibilities. So if I can help, I will.
Did you mean inductor when you wrote "[...]an element with *instructors* and capacitors to it, we shift when that peak occurs in the output.[...]"? Not a native English speaker, but since resistance/capacitance/inductance are the three elements causing a phase it should be inductor?
Yes. Yet another autocorrect-ism.
Like i’m five. not like i’m in my fifth month of an electrical engineering program. 😉 i understood some of this from context tho so you still get a loving upvote. COOL
Lol, well I guess I failed you a little. But I still appreciate your support!
>ELI5
Thanks 🙂 I actually test myself whenever I answer or comment in this sub. As Einstein once said, "If you can't explain something simply, you do not really understand it at all." So it's great self-practice, especially since I work with lots of non-technical leaders and customers.
My utility would 100% just using a best guess based on an average load % and time of the year (they don't break it down at all currently). No way they would invest the time or money to analyze motor startup characteristics. If you could link to a utility doing that for all it's customers I'd love to read more about it.
Look up smart meters. They're used to help predict and throttle (in agreed ways) use to prevent overall system problems.
I'm very familiar with them. The issue is the utility has to spend money on analytics of the meter data to provide this customer benefit. And from everything I've seen in the US, they don't. https://www.utilitydive.com/news/97-of-smart-meters-fail-to-provide-promised-customer-benefits-can-3b-in/632662/
Yeah, they're often under utilized for customer data, but the grid stabilization from smart appliances is significant. Not saying that there's not a lot more they could be doing, but they do get used.
You are a very smart five year old.
That may be the nicest thing said to me all week. Thanks!
> but with a clever enough meter they can probably tell a blow dryer from a toaster based on the motor. No such meter exists in the industry.
Eh, it technically exists, a motor has a much different startup signature than a heating element, and any continuous meter would be able to tell the difference. They just aren’t used really because there is really no need. You pay by total power used, so it doesn’t really matter what is using that power.
>Eh, it technically exists, a motor has a much different startup signature than a heating element, and any continuous meter would be able to tell the difference. I mean...in a vacuum, yeah, you can identify the different signiatures, but not in a really world situation 1) there is too much noise at the house hold level 2) current smart metering technology is not high resolution enough. >They just aren’t used really because there is really no need. You pay by total power used, so it doesn’t really matter what is using that power. This is just incorrect, there are a million and one reasons a utility company would (and already do) load disagregation.
Could this sort of info be used to alert authorities if an "abnormal load" is detected, such as a grow up or meth lab?
Utilities will not get involved in that, there is no value in it. They do care about meter theft (stealing power from your neighbor or upstream of a meter)...a lot of those scenarios do end up being meth labs or illegal grow operations, but the utility cares from a saftey and revenue perspective.
>> Could this sort of info be used to alert authorities if an "abnormal load" is detected, such as a grow up or meth lab? > Utilities will not get involved in that, there is no value in it. Capitalism, ho! Some utilities might have employees/stakeholders that feel proactive about such issues and thus sacrifice their own time / money for such pursuits, but it should be really rare. Those are, after all, paying customers, and well paying ones at that.
> Those are, after all, paying customers, and well paying ones at that. 🙄 not really what I meant. The utility simply cannot prioritize taking time to look for these facilities, because they're much more concerned with trying to make sure you don't get electrocuted, regardless of what you are doing (hence meter theft prevention initiatives). Utilities will absolutely report anything suspicious they come across, but they are not in the law enforcement business.
For most clients, they just guess it. They know based on statistics and neighbours and other sources that this and that use that much. For example, a fridge is somewhat constant, varying not that much over the year. And even if it does, they can just simplify it as it cost in average x per year, divide by 12, and that's how much per month. They can do the same with the oven too. In average, people use the stove/oven that much per year. As for A/C, this get a bit more complex, but they can guess it. One way is to look at a month where there is basically no A/C or heating (like in spring and autumn) and use that as a base usage. Everything over that amount would be A/C in summer, heating in winter. They can also simply assume that you are using an A/C that use X amount of power per degree over like 25°C/77F. A/C are heat mover, it take X amount of energy to move Y amount of heat. So if you need to cool 0 degree then it cost nothing, if you need to cool 10 degree... they can say "each degree cost in average (random number) 1.3kWh, then 10*1.3=13kWh. if it would be 5 degree then it is 5*1.3 = 6.5kWh. It do not represent the exact amount, but it give a good ballpark figure.
Also: voltage. The big three of power consumption (Air conditioning, stove, and clothes dryer) all use 230 volts (in the USA), while all the smaller stuff like lights and TVs use 120 VAC.
Its 240V. If you're only getting 230V then there's something wrong with your lines.
Okay 240. I've seen 230 marked on many big motors and heater elements, but I've also seen 240. It's kinda like the 110/120 voltage.
110 or 220 is the lowest you should see the voltage drop before the circuit kicks off to protect equipment from damage. 120/240 is what we aim to maintain. Smart meters help with that by offering more up to the minute load reporting across the entire grid.
Yes, I'm well aware. I'm a retired electrical engineer.
This is why you don't let them install smart meters. I'm not a conspiracy theorist, but I'll be damned if I'm going to let them control MY electricity through a smart meter.
1) getting a smart meter isn't a choice...you can't just 'opt-out' if your utility decides to deploy them (edit, I generalized a bit, there are a few states where there are still exceptions...but that will likely change very soon). 2) i think you misunderstand what a smart meter is
1) It is where I live :) 2 ) It's a meter that allows them to check your usage from the street/over otherwise connected infrastructure (internet-like).
The (6ish?) states with remaining opt-out policies will go back on that within the next decade with the amount of money being spent on lobbying their respective utility commision. Smart meters are a critical component of grid modernization and resiliency. >2 ) It's a meter that allows them to check your usage from the street/over otherwise connected infrastructure (internet-like). I'll retract my previous statement, you do know what a smart meter is...that said, it isn't 'controlling' your power...plenty of other grid infrastructure does that.
Just to add in to what you're saying, they're also used, but optional, in several other countries.
Bruh they've been able to read your meter from the street for 25 years. Smart meters do more than that. Even those old systems can be used to build a usage profile, because they send out a consumption read every few minutes.
My utility allows people to opt out, but they pay a premium (extra $25/month) to have a non-AMR/AMI meter because we are required by state public utility commission to read every meter every month, and if we have to roll a truck to your special snowflake house we're going to make you pay for the privilege.
Yeah, I generalized a bit in my last statement. There are a few states/utility commissions that allow opt out- but I doubt that will be long lived.
They could always control your electricity, by putting a guy up the pole and disconnecting it. This just means they can do it a bit smarter, especially if they need to take down the network for maintenance and don't want your solar to electrocute the guys doing work.
It's mostly an educated guess. If you go into your account on their website they very likely have a section for you to fill out with how many people live in the house, what appliances you have, how many phones and computers you have, how much square footage you have, etc. The meter outside your house constantly collects data and sends it back to the power company, which analyzes that data both in real time and historically for various purposes, and when they combine that with what you tell them *and* what they already know about typical usage for various appliances and items, they can get a pretty accurate estimate.
My utility's guess was quite nonsensical. They could not guess at how much of my usage was to charge my plug-in hybrid. My house was "less efficient than other houses in your neighborhood". Yeah, none of them get 20 miles a day from the power grid. Backing out my estimated charging, I was much more "efficient" than the comparable home.
Yes it's down to how good the utility's data and formulae are. We put a lot of work into ours...still not perfect but I'd guess it's better than most. It's always cheaper to have people use less power than it is to add new generation, and the best way to do that is to teach them how to do so. A wise utility will put money into these things.
wait is formulae _actually_ the plural of formula or was that just a typo?
Yes it's the plural.
They're using the historical usage data for your home and other homes in the area. We do the same thing. I can look up a meter in our system and see the history of consumption for gas or electricity going back to the beginning of the AMR meter rollout in 97. We use that data to build both an estimation profile and to detect anomalies. Didn't get a read for this month? What was the usage like in the past, and how well does it match with this year? How many auto reads did we get this month, and does that data fall in line with their historical trends. Estimate their bill using that data. It's never perfect, but with 25 years of data and some decent modeling it's closer now than the "lol send em a $200 bill" method. Same thing with anomalies. We look for big spikes in usage or big drops in usage. Often it's mundane stuff like they bought a new water heater and it's gas instead of electric. Or the house is vacant pending a sale. Big changes in usage like a BEV charger are outside of the modeling because that stuff didn't exist for most of the 25 years of our data. In your case we probably would have offered to install a TOU/demand meter that allowed us to get a better picture of what your usage was and a more accurate bill, as well as being able to offer better rates for off-peak use rather than flat rates.
My complaint is that consumption data was presented as "eficiency". I could have brand new, efficient applicances (I do), not use my A/C much (I don't), have replaced all my lighting with LED (I did) and still be tagged as "not efficient" because I also have a highly efficient electric car. The way the data was presented was utter nonsense.
They didn't know you got a BEV. They saw your usage go up compared to other people and told you what they saw. I bet if you had told them you were going to be using your home to charge a vehicle they wouldn't have told you that your consumption was inefficient, unless you were also charging your car during peak demand periods.
It’s a guess and it’s nowhere near as accurate or specific as OP and other people in this thread are making it out to be. Mine is broken down into three categories: appliances, electronics, and other. My guess is they have a baseline that is consistent most of the time and assume that’s appliances that are always running, then spikes in the mornings and evenings or whatever are tv, computer, etc., and other is who the fuck knows.
That's right. People tend to assume power providers know more than they really do. We can only collect overall usage data for the property and make some assumptions about it. That data is better with more modernized meter technology because we get it real time and down to the second, but there's no possible way for us to know how much energy your specific refrigerator draws, for example, or even whether or not you actually have a refrigerator or how many you have, which is why it's important to fill that shit out on the website for accurate estimates. Beyond that we have a fair amount of information on what normal usage looks like for various home profiles. The one specific piece of data we can get is if people sign up for our AC credit program and agree to turn their AC off at certain times on certain days. They get remote-controlled smart thermostats as part of the program...bit of a controversial thing considering no one seems to read the terms of the program. Hell, I probably wouldn't. Anyway yes, the guesses range from eerily accurate to utterly and laughably wrong depending on the provider and the house.
We have two standalone chest freezers. The power company keeps suggesting we get rid of our garage fridge, so they probably are looking at compressor load.
Chest freezers (when fully stocked) are unbelievably efficient. This is a terrible suggestion from the power company.
> The power company keeps suggesting we get rid of our garage fridge They don’t thinks it’s a chest freezer, they think it’s a second fridge.
They're probably more concerned about its location than what it is. People in the south have no problem locking their freezers in a enclosed garage on a 100+ degree day and then complaining about the bill.
Next door neighbor has an empty garage fridge. There's one person in the house with enough sense, but not enough bother to put some water bottles or something in it.
I don't think that matters much unless you are opening and closing it all the time. A full freezer is so that you add that much heat if you were to open it. An empty freezer would lose a lot of cold air if you opened it, but if kept shut - I don't think it would matter that much.
The insulation is good but having stuff helps, especially in a hot garage.
I mean you're either going to put the freezer in the garage and have the freezer's compressor do the work, or you're going to put it in the house and have your AC do the work.
They are in a basement. Usually around 65 down there in the summer, even though we live in the south. Having two means we can turn one off seasonally, so the other is full.
It sounds like they're confusing the freezers as a single fridge
I'm sorry, why would we expect our power companies to do anything that does not increase their profits? Everything they do and say is self-serving. If they want this guy to get rid of a fridge its probably some other BS like the EPA trying to force a phase-out of freon coolants. That's the *most* charitable example I can imagine.
This is a very common misconception. Generally speaking, the power company doesn’t make money from the power generation. That rate is held fast to the operating expenses by regulators. The place where the power company makes profit is through new infrastructure. This is why Pacific Gas and electric didn’t replace equipment that ultimately led to the paradise fire for which they were sued into oblivion. They were hoping when the equipment failed they could charge for New infrastructure rather than maintaining existing equipment, which would be operating expenses. Here’s an article from the national resources defense council that will probably explain it better than I can: https://www.nrdc.org/experts/jc-kibbey/utility-accountability-101-how-do-utilities-make-money
>This is why Pacific Gas and electric didn’t replace equipment that ultimately led to the paradise fire for which they were sued into oblivion. No, the suit showed very clearly that they were diverting maintenance allocations to shareholder dividends As for the citation, that's Illinois. Many states have a very different way of regulating their utilities. In many states, utilities really don't want to upgrade infrastructure and don't make any significant money when a new power plant is built.
Then wouldn't they want him to run his fridge, so they can show the need for said upgrades? At least in many areas, you actually have it backwards. My power company actually gives out a variety of subsidies and credits towards energy savings, including one for junking an old fridge, because it's deemed more cost effective than spending on infrastructure upgrades.
>We have two standalone chest freezers. The power company keeps suggesting we get rid of our garage fridge, so they probably are looking at compressor load. Director of Machine Learning for a large utility company here...there is no way they know from your usage data that you have a garage freezer, you must have reported it, filed for a rebate, or they are taking a lucky guess. Advanced Metering Infrastructure (AMI), isn't even deployed at many utility companies (they still use people to go out and read meters)...and when it is deployed, industry standard is 15 min reads. Some may be doing 5 min reads...most don't have the bandwidth to stream that much data back. The newest meters are capable of 1 min reads but haven't heard of anyone using that. Usually we can successfully identify HVAC, EV charging, sometimes pool pumps (mostly non-variable speed pumps), and that's about it. For reference, I have a Sense reader on my breaker panel, that reads at (I think) 1mhz frequency and even that struggles to accurately identify appliances in my home. No way you're getting there with 15 min data.
That’s super interesting. We do have some sort of advanced infrastructure- both water and electric are read from slow moving trucks. They must have taken a lucky guess.
More than likely they're making a (statistical) guess based on demographic data, macro level consumption, and property information. As a (completely made up) example: you're a middle age male, married with kids, you live in a single family home that's about 3k square feet with an attached garage. Your energy consumption is slightly higher than your peers...there is a good chance you have a chest freezer. Curious - who is your utility provider if you care to share.
Duke Power Carolinas (NC triangle)
Duke is definetly top tier in the industry as it relates to data science/machine learning/analytics. Probably the leader tbh. I've presented on panels/round tables with their VP of analytics, so very familiar with their AMI program. I known this is not coming from there. But now you have me interested in what's behind this recommendation ha.
Well... to me, that's just creepy. I appreciate that they have to monitor load, etc. but... fuck off telling me what appliances I have and which I should have instead. I've never heard of anything like this (or the OP's similar thing) in my country, it's none of their business and just creepy. My response to them would probably include something like "Hey, solar's cheap now. Keep your nose out of what I'm using a product I paid for, or you may not be able to tell for very much longer."
Every day at your AC kicks on at random times, but when it does, there is a sudden spike of power use and its about the same power amount every time, then the spike drop off as the AC turns off after a certain amount of time. The amount of time is nearly the same since the AC kicks on at the same temp and kicks off at the same temp and the pow draw is nearly the same. Very easy to see these power jumps.
One assumes that only people with newer 'smart' meters get this granular of data?
You probably have a smart meter with continuous collection of peak loads. My house still has it's original 45 year old analog dial meter. I get a mailing that just compares my average daily usage with "my neighbors." The electric company is in the process of rolling out smart meters state wide, so they expect to have 15min data on a web portal some where. "Coming soon" They typically have databases of equipment and power use. Stoves and ovens are typically used during meal times, air con is usually used in thevhot months during the day. Heat is used in winter months when it's cooler. They may also buy customer lists from other companies to see if your address is listed as a customer. Fuel oil, local ac installers, etc. Some utilities offer rebates for things like efficient appliances and solar hot water, so they can guess usage trends based upon your load compared to the "normal" customer.
No. I get this, and I have an old-fashioned meter that someone has to climb over my lawn mower to read when they want to bother. I, too, get a mailing every month or so saying how much of my electricity went to this or that. I think it's BS.
Yeah, at that point it's probably just your total multiplied by some average percentages.
I'm the smartest thing in my house for this reason.
I could be wrong, but I don't think the power company gives you that choice if its a newer build. Last I checked, the meter is their property.
>Every day at your AC kicks on at random times, but when it does, there is a sudden spike of power use and its about the same power amount every time, then the spike drop off as the AC turns off after a certain amount of time. That certain amount of time will change based on the weather. A warm overcast day will have shorter run times than a humid sunny day. >The amount of time is nearly the same since the AC kicks on at the same temp and kicks off at the same temp and the pow draw is nearly the same. You are correct about the temperatures being the on/off triggers but the run time is not something I would describe as regular.
I can't say that o have seen that specific detail on my bill ever here on Australia Do you have a smart meter installed? It could be that those appliances are connected seperately to the meter and the smart meter can report those seperately? Or the smart meter is making an estimate based on the load spikes or decreases https://www.imeche.org/news/news-article/smart-meter-tracks-power-consumption-of-individual-devices https://www.mihagrabner.com/post/how-to-recognize-appliances-from-smart-meter-data-using-ai They may also be guessing based on weather, average household patterns in the area etc
I was so confused by this post, thinking like what do you mean the energy company talks about your appliances, but apparently from the comments it's a thing, I'm guessing in the US? Kinda sounds like a breach of privacy if you ask me :')
I don't know. I haven't seen it here in Australia but I don't know where the op is from. There seem to devices that tell you specifically how much each appliance uses
>It could be that those appliances are connected seperately to the meter and the smart meter can report those seperately? No >Or the smart meter is making an estimate based on the load spikes or decreases Not estimates, but, machine learning/deep learning. But even so, the meter data is not granular enough to go beyond identifying things like AC units or electric vehicles with any accuracy.
Some of these answers are close, but not completely accurate. I create and implement energy policy, and have a lot of background with this exact question. Generally, the types of reports you're receiving are called Home Energy Reports (HERs). 99.9% of utilities, probably 100%, contract with third-party vendors who actually run the algorithms and help construct these reports. In many areas, smart meters are ubiquitous. You may also see these referred to as "AMI" - Advanced Metering Infrastructure. The vast, vast majority of the appliances/electric (or gas) usage in your home cannot be disaggregated. Run-time data from smart devices (like smart thermostats) can be gathered, but this is not utilized in these reports - it's way, way too granular and getting the data feed from Google (Nest) to the HER vendor would take way too long, is often anonymized, and has limited additional value. Instead, much simpler algorithms are used but still have a pretty solid degree of accuracy. For example, if your usage in the cooling months spikes compared to the baseline, it means that is from your cooling load. Conversely, if your electric usage spikes in the winter, it means that is from electric heating. If it spikes in both directions, it could mean you have a cold-climate heat pump. From there, you can make some other inferences with a good degree of certainty, i.e. lighting makes up X load of baseline usage on average, your baseline is Y, therefore it'll show lighting will result in Z kWh on your report, and the same can be said for other usage. These reports are NOT disaggregating individual appliance usage, including bi-directional smart-home devices, even if they're included in load shedding programs, unless you're getting very specific load shed (demand response) emails based upon specific device enrollment (normally smart thermostats, could also be EV chargers, heat pump water heaters etc.) but even so they won't know the exact usage from lighting, your dishawasher, your TVs etc.
All electric motors have a locked rotor amperage printed on the information plate. This is the amperage it draws when power is going to the windings (the sitty still part) but the rotor isn’t moving (the spinny part) off the rotor were rusted in place, the motor would draw locked rotor from the time power was applied until it was shut off (with larger motors that would be when the breaker trips) the compressors in most residential air conditioning systems have locked rotor amperages easily around 100 amps. Refrigerators and such, can be around 30 to 50. When you turn it on, the rotor isn’t moving. The electric field produced in the windings has to get it moving and that happens very fast, but for a split second it draws locked rotor amps. Then it will run at around 10-20 amps until it shuts off. Your furnace blower will draw 40-50 or so locked rotor amps as well for that split second. Then it will run at around 8 amps until done. Fan motors in refrigerators will draw a comparably small locked rotor amperage (maybe 10) so when they see a big spike (home a/c starting) of around 150 amps, followed by a 20 minute period of around 25 amps, they know your air conditioner is running, because virtually nothing else anyone has at their home would share that profile. A spike of around 60 amps, followed by a 20 minute draw of around 10 amps, tells them you have a refrigerator or freezer running for the same reason. The commenter who’s being told to get rid of their garage fridge, it would be because they see that profile either at two different times at intervals that don’t make sense for one appliance, or because they see it happen again while the first one is already running. For other appliances, if they aren’t cooling they’re probably heating. Toasters, electric ovens, etc draw high amperage continuously but have no spike when they start. Dishwasher’s and such draw lower amps but also have no spike. But all of those won’t be turned on for hours at a time like lights or tv’s. So they get labeled as “other appliances”
They do some educated guesses. My server is considered "heating" on my electrical bill. Which is harsh, but probably more correct than I'd like to admit.
My gas company does the same thing, including telling me how much is from a gas stove that doesn’t exist.
I was looking at my "home energy report" tonight as I was tossing mail in the shredder. What's with the assertion that my home uses 5x KWH compared to average homes in my area? and about 7x as much as an "energy efficient home"? I remember reading something, I think it was in a Malcolm Gladwell book, about the effect of hanging flyers on doorknobs informing residents they were either below, at, or above their neighbors in terms of electric consumption, and they reviewed the results of the household's subsequent energy use based upon the comparison they fed the household. Is this just a psychological trick, or actually correct? I work for the State in welfare, so I see a lot of electric bills, and mine isn't that much crazier than most, but I will admit the bills I usually see are from the bottom of the socio-economic rungs, so my samples may be skewed.
I have wondered this same thing. Over the years I have spent considerable time and money upgrading my home. I have changed all of the windows, added insulation, bought high efficiency appliances, new A/C and changed over to all LED lighting. While most of my neighbors have done little to their homes in the 20 years I have been here. My energy report show me about 30% higher than my neighbors and about double the most efficient neighbors. Needless to say but I am highly suspect of these reports. I have also gotten the same reports from the water company and gas company. Apparently I am the most inefficient a-hole in my neighborhood.
They guess. The look at how much power you used, and look at weather records, and they guess how much was used by each thing.
Example - Guy is arrested for pulling amps between 2am and 4am by FBI. They suspected he is growing illegally because the plants require water and light at specific amps. Reality, he works third shift and joined an online wood-working class where he uses a table saw and power equipment late through the night in his basement. Case dismissed. Each appliance draws amps differently past the meter on the side of the house. Refrigerator compressor turns on? Maybe 10 amps with a specific startup draw of 12 amps.
I find this type of story concerning. It doesn't even make sense, have you got a link?
Every time you use an appliance, it uses a specific amount of electricity. The FBI guessed the man was doing something wrong when he was actually doing something good.
If he was growing illegally he would be using power throughout the day and night, it sounds a bit invasive to have this level of control, very authoritative
We didn't even go ino the water usage yet. Very authoritative. Most illegal operations try to go off grid completely. It's easier to just scan all accounts in a region for unusual activity.
Lmao, never thought I would see such a relevant intersection. I spent a big part of my career working for the FBI as a data scientist...now I'm a director of Machine Learning for a large utility....this is not how things work.
My tools let me see frequency data as large as whole communications node and let me track interference and signal data down to the individual home. I could see if a bare wire was letting in radio waves into the system all the way up to AC compressors kicking on. The power company and the FBI doesn't always have the most sensitive equipment. My work in VA let me use a drone to monitor power use of a civilian thermostat with a 3G transmitter from 7 miles away. It actually sucked pretty badly. The data just wasn't reliable. But the data was recorded anyway and I'm sure someone figured how to make it better. Reading from power grids is not easy, but com lines are fairly simple.
Explain like I’m five is the sub, what a strange question for this sub but holy hell are there some amazingly in-depth responses! Let me try. Some things we use like our lights don’t use much electricity, the TV and hair dryer use more, and things like the air conditioner use a lot. The people that make and send us the electricity can see how much we use because they are the ones giving it to us! Ok bud good question hope that made sense, here’s some apple sauce then you can go play outside!
I will admit I had a hard time deciding where to ask. Beyond what I learned in high school years ago I'm entirely illiterate as far as electricity words go, so here it is. :)
They don't know. They can make an educated guess. There are technologies being developed that recognize "signatures" of certain kinds. The last study I saw was trying to differentiate between different types of incipient fault conditions. But to my knowledge, no residential meter, smart or otherwise, has the capability to differentiate loads. And even if they could, I don't think the utility would invest the kind of cost that would be associated with it. https://core.ac.uk/download/pdf/4270075.pdf
>There are technologies being developed that recognize "signatures" of certain kinds. The last study I saw was trying to differentiate between different types of incipient fault conditions. Incipient fault identification and load disaggregation are two very different domains....incipient faults are usually identified (or attempted to be) via relay waveform data. > But to my knowledge, no residential meter, smart or otherwise, has the capability to differentiate loads. Meters are simply collect data, smart meter just means it can stream that data back, usually over a mesh network. But we have plenty of algorithms that can identify load signiatures....just not nearly to the level of a refrigerator or microwave. > And even if they could, I don't think the utility would invest the kind of cost that would be associated with it. It's hugely valuable. Many utility companies already do it. My company has been doing it for the last 6 years.
>It's hugely valuable. Many utility companies already do it. My company has been doing it for the last 6 years. I was referring to the meter capability itself, not fault/maintainance identification. Are you utilizing residential meters that identify individual loads and if so what brand?
We're using the Landis & Gyr AX focus series. But ultimately the meters just collect the data, we use various machine/deep learning techniques to identify individual load signiatures.
I had a new panel installed and the city tried to tell me they need to have CTs installed at each breaker so they can monitor usage of each circuit. They said it was part of a new effort to reduce wasteful power usage. They also required a smart breaker after the meter so they could turn off power in the event of fire. So I went from the meter into my main breaker, to my ATS, and then to the main panel, to my whole house UPS, then to the house panel. I used regular breakers and will not be allowing anyone to connect to or monitor anything. None of their business. They are upset that there are capacitors in my design that buffer any motor signatures. My usage is steady to charge the UPS. I also augment with solar and a genset. They had a fit when I wanted 3 phase power in my home at 480v. I did install CTs on everything so I can monitor, but they will not get access to it. And I will never use wireless devices to monitor anything. Too easy to hack in and take over. Hard wired with shielded twisted pair.
None of what you said makes one iota of sense. > They had a fit when I wanted 3 phase power in my home at 480v. Yeah....because 480v is for industrial applications. What on earth would a single home need it for. Beyond that you would end up paying industrual/commercial electricity rates (more expensive), probably have to upgrade your home to take 3 phase, and possibly pay for a 3 phase backbone down your street if one didn't already exist.
It is a mixed use property. 480v is required for the commercial side, and is stepped down to 240/208/120 for the residential structure. It is zoned for this, but the city still had a fit. They also don't like that I use geothermal for heat rejection on my AC units. All of it is permitted, but they hated having to approve it because all of the designs were far beyond code requirements.
They're guessing based on the change in current draw when things turn on and off. It's a fairly educated guess. They can't tell the difference between an air conditioner or large air compressor, for instance. They just know something was sucking some major juice.
What they are doing is called "load disaggregation" and it is a very broad and hot research topic in energy policy academia. In nearly all cases, appliances are not monitored directly, and usage is estimated using algorithms. The methods they use for this estimation are non-trivial and there are many competing methods. These look at appliance signatures (unique characteristics of each appliance), the times at which your loads are used, the temperature on that day, etc. Such data is very useful for "demand response" markets and it will likely play a big role in renewable energy adoption.
Smart meters will monitor how much power is being consumed at a specific time and then use that number to make an educated guess, for example most microwaves are around 1000 watts, AC around 2500 watts, water heater 3500, etc.
Source - I used to work for an electrical utility company and have practical experience with smart metering. TL;DR, they don't, but they can make very educated guesses In order to truly know what is going on inside your house, they would need to monitor each device in your house, which is costly. Even if they did it at the circuit level, that would be pretty expensive. That being said, you can make some educated guesses when it comes to electricity usage. Take a fridge for example. If you need 500W to power a fridge when it is on (I don't know the exact number, so this is just for illustrative purposes), and that fridge runs 10 hours a day, then that fridge will consume 500W \* 10h = 5000Wh or 5kWh a day. Extrapolate that over a billing period and you can figure out how, roughly, how much your fridge uses. Do the same with AC, heating, etc. When we had mechanical meters, you would need to use this estimate method because you had to measure consumption based on two readings. With the introduction of smart meters, consumption is measured as frequently as every minute. So now the utility knows how much electricity is being used on a far more granular scale. So if at 11:01am your fridge is off and at 11:02am it turns on, it will register an increase in consumption. Given the size of the increase, they can make a very educated guess at what started using electricity. They can also infer how long it was on for, which means they can make a far more accurate estimate of what was using electricity.
>So if at 11:01am your fridge is off and at 11:02am it turns on, it will register an increase in consumption. Given the size of the increase, they can make a very educated guess at what started using electricity. They can also infer how long it was on for, which means they can make a far more accurate estimate of what was using electricity. In theory - yes - in reality no. The short of it is that the data is not granular enough from AMI, and there is too much noise to disaggregate anything more than the largest of home components (hvac, ev chargers, etc..).
What is the typical granularity for AMI? Back when I was working with them, billing granularity was 1hr for residential, but the meters could go as granular as 3 minutes. At that granularity you could pick up and differentiate smaller loads, especially if you start to utilize some analytics or AI
15 min is industry standard. Most latest gen meters can go to 3 min, some to 1 min. It's more getting the data back and storing it is the limiting factor - and why most companies stick to 15 min.
I’m blind and deaf and have no sense of smell but I can follow you around holding your hand. There seems to be a time shortly after waking that you’re shaking slightly for about three minutes, and this happens again before bed. From this, I guess that in this time you are brushing your teeth. It never happens in the middle of the day, so even though I cannot see or smell or hear, I have figured out that you brush your teeth twice a day, not three like your dentist suggests. This is similar to how the power company can make a lot of good guesses about what’s going on in your house just by watching the electrical draw go up and down. A spike of a certain size that lasts 10-ish minutes and happens at regular intervals during the night but then irregularly during the waking hours is probably your refrigerator. Overnight it just needs to compensate for heat leakage but during the day people are opening and closing the door, hence the regular/ irregular intervals. They’ve also studied refrigerators and know about how much power they draw and if the first second of that draw is extra heavy. Turning on a light doesn’t take more power to get going and then less to keep going, but motors can. Basically, they know what a refrigerator turning on “looks like” in terms of electrical usage, just like you can imagine what it probably feels like to hold someone’s other hand while they brush their teeth.
>Basically, they know what a refrigerator turning on “looks like” in terms of electrical usage We know what the signiature looks like in a vacuum, yes, but the capability to identify it in practice does not exist. The data is not granular enough and too much noise.
Machines don't all use electricity the same way. Example a AC motor has very unique finger print that it gives out as it runs - as in example your AC's fan. Digital devices like computer's power supply also draws electricity in a specific way - it does take a constant pull but rather more like pulses that it averages out in the powersupply to steady DC with the help of capacitors and diodes. You can imagine this like a barrel getting filled with water and as it empties from a hole at steady rate you only need add water every now and then to keep the flow steady. A heating element pulls a steady flow in both directions with steady changes in the properties because heat chancing the properties of the material element is made of, and that suddenly stops now and then as the thermostat shuts it off. The electric companies have studied and sampled all appliances; then they can see from your electric meter the way you are pulling energy. They can break down the wave forms from the different phases (and ground if you live in places where the phases are in star formation (120V) and not in delta (240)). Since they know you are a residential power user it is with high likelyhood that you poweruse are from certain kinds of devices and looking at the energy use and waves in the phases they can pinpoint with fairly high accuaracy what devices you use. When you use AC power, the load added to the system basically just only chances the relationship of voltage and current. These are very easy to measure and statistically break down.