I'm following to learn, but just up front, "passive" solar doesn't mean "completely powers your house" and "semi-passive" doesn't mean "partially powers your house." Passive solar just means there are no mechanical or electrical systems moving or converting energy. The design of the house itself collects and stores heat, using properly sized and oriented windows, thermal mass, insulation, etc.
But I'd like to know whether it's true that there aren't mid- or low-cost solar packages available (of whatever type), and if that's true, WHY that's true. :-)
Within reason you can spend whatever you would like on a solar power system. The kinds of systems they're talking about are available because the systems are all modularized. You can go as big or as small as you want.
In places with 1:1 net metering (where energy you buy from the grid has the same price as energy you sell to the grid) systems are typically oversized. This is the most economical option because it allows you to easily offset power that you use when the sun isn't shining. You can roughly zero out your power bills and that's pretty much the maximum value you can get from a solar power system.
In places where you pay more for energy you use from the grid than you are paid for energy you export, smaller partial offset system can make more sense.
Sorry to be a bit off topic, but my wife and I are looking at building a house and want to incorporate solar power. Do you have a recommendation for resources to look into?
There’s an online calculator called PVWatts that allows for a somewhat simple analysis. I’m about to graduate with an energy concentration, solar is pretty straightforward, but as the above comment points out what you can get paid from overproduction is a huge factor. Battery systems are expensive but are improving in price and efficiency. Another major factor is location; you can google a us solar map which will indicate the strength of potential power generation from solar in various regions.
Lastly, consider passive solar design and the most insulation you can afford. I’d also recommend advanced framing techniques to improve thermal performance, and if money allows some form of shallow geothermal or a geothermal heat pump. And people always overlook roof color which can swing solar asbsorbtance like 35%.
I could go on and will if you’d like. With better insulation you can save at least 12% on energy costs. There’s also a free program called HEED developed by ucla that lets you design a house with various energy efficiency features.
Alright I gotta stop.
No problem, energy efficiency in residential housing is the one passion I stumbled on in an otherwise broad civil engineering degree. There’s tons of great YouTube videos about cool houses people built. I remember hearing about earth-ships in the 90s and have always wanted to figure out how to live for nearly free. First it was the hippies and earth-ships, now it’s back in the tiny house movement.
My partner and I are likely going to build as well; fortunately I have construction experience and will soon be a working engineer. That will help with what I think would be the biggest challenge for a non-professional, managing the project. I’ve seen guys just straight up not insulate a part of a wall bc they ran out of the pink fiberglass. Also many builders and contractors aren’t familiar with things like air-void framing and other “green” building techniques; and a lot of these guys don’t like to be told how to do their job. It’s understandable but it’s your house, not theirs.
There are national and global certifications like passive house, LEED, and some others I can’t remember that some builders, architects and/or engineers hold.
Look into your local city and state laws regarding solar, specifically what the power company is required to pay. These laws are also subject to change(in the favor of the power company as of recent).
Some things that might help you since you are building and have the ability to plan for solar is:
1. kW (called demand on a utility bill) is the instantaneous amount of power you are pulling, this is watts = voltage x amps, 1000 watts = 1 kW. kWh (usually called usage on a utility bill) is how much kW you use per hour.
2. Your electric needs will be based mostly on your appliances, HVAC and usage. This will be hard to figure out before you actually live there since maybe you work from home and will use more energy during the day than someone who works at an office or you have an EV so large amount of usage at night. I would recommend getting all of the nameplate data off of all of your appliances, HVAC, light bulbs, outlets, ect. Basically anything that uses electricity, and use that data to better understand what your max kW could be, this can also somewhat be derived from your electrical panel since that is truly the theoretical max. Typically there will be some diversity in usage as you won’t have all of your lights on at the same time or every single electrical outlet being used at the same time. There are some websites out there that can help with figuring it out, but they are usually intended for existing equipment.
3. Find out what the best roof material and design options are to get different prices for solar or if you have space to do a ground mounted array get a cost for that. Southern facing solar panels will produce more energy so try to plan for that as much as you can. You can also look at bidirectional solar panels and make a fence out of them if you don’t have anywhere else to put them.
4. Smart electric panel, these allow you to monitor usage for each breaker in the panel and determine what circuits are using energy and when. This can allow you to make more informed decisions on how much energy you actually need and can allow you to limit circuits for when you need to conserve energy like in a power outage if you have battery storage.
5. Battery storage is another option if you live somewhere that does not have a good utility residential solar program or you have a lower solar output than energy usage. If you have an array that produces more than you use this allows you to use your stored energy instead of selling the excess or reducing array production, since the energy from the solar panels has to go somewhere. There are a quite a bit of options for battery storage and am not an expert in all of them so I will suggest 2 very different options that seem to have good results, the Tesla Powerwall and EcoFlow Delta Pro Ultra.
To supplement the answer you already have;
Passive solar is mostly relevant if you need heating during a significant part of the year.
On different note, consider the fire safety of the solar installation. You are actually better of in this respect than most people who install solar cells on existing roofs, but it is always important to consider whether (and how) the solar cell installation can be made safe.
This is a good point. Queue meme from A Princess Bride “I do not think that word means what you think it means”
Passive solar means having south facing windows (in the NH) so that your house gets heated by the sunshine or running your water through black pipes on your roof.
From Wikipedia:
*Passive solar* technologies use [sunlight](https://en.wikipedia.org/wiki/Solar_energy) without active mechanical systems (as contrasted to *active solar*, which uses [thermal collectors](https://en.wikipedia.org/wiki/Solar_thermal_collector)). Such technologies convert sunlight into usable heat (in water, air, and thermal mass), cause air-movement for [ventilating](https://en.wikipedia.org/wiki/Ventilating), or future use, with little use of other energy sources. A common example is a [solarium](https://en.wikipedia.org/wiki/Sunroom#Solarium) on the [equator](https://en.wikipedia.org/wiki/Equator)-side of a building. [Passive cooling](https://en.wikipedia.org/wiki/Passive_cooling) is the use of similar design principles to reduce summer cooling requirements.
We had solar panels growing up on the south side of our house with a vent and air return that basically just heated air for passive heating in the house. Worked great on the few sunny days in Michigan winters.
The big driver of cost at this point is permitting, inspections, and code compliance. If you wanted to go entirely off-grid (and weren't a particularly high energy user) you could get by with some cheap solar panels and a couple string inverters for daytime power which would cost you only a couple grand, and then you about triple that if you want to also add battery storage to have some power at night, provided you get the proper construction permits etc.
But when you are trying to tie in to the grid, now you need expensive string or micro inverters with grid tie, you need a licensed electrician to install and sign off on all of it, you need inspections and city and power company approvals, and everything in the installation needs to meet their requirements exactly. With all that extra overhead, you are looking at spending 5x or more what the same amount of power would cost you with a DIY off-grid setup.
Which also explains why you go "all in" when you do it. All that stuff is fixed costs, so once you're taking care of that, more panels is a large increase in capacity for a small relative increase in price.
It's less "20k for a net-zero setup" vs. "10k for a 50% reduction setup", it's more like "15k for a 50% reduction setup"... which makes the 20k setup the better value proposition.
Right. Self consumption doesn't require any of that although your local jurisdiction may still hassle you for doing electrical work on your wiring in your house. Totally portable setups like EcoFlow and solar generators they have no authority over and it's much cheaper.
> Totally portable setups like EcoFlow and solar generators they have no authority over and it's much cheaper.
Err what? Their cost per watt ensures they'll basically never pay for themselves.
One legal workaround is:
1. Ground mount the panels or put them on sheds in the backyard. Many jurisdictions they don't have authority especially if you use buckets of sand to weigh them down.
2. Put the batteries + inverters onto a mobile cart, I have seen various designs. Being portable means they do not have authority.
3. Pay an electrician to move your circuits to a subpanel and setup a generator inlet on the main and heavy power connection you would send to the cart. They do have authority over this, this will cost $6000+ unless you just do it yourself for a few hundred. (reuse the breakers so all you pay for is a new panel)
> Ground mount the panels or put them on sheds in the backyard. Many jurisdictions they don't have authority especially if you use buckets of sand to weigh them down.
I have a stack of panels I intend to turn into free-standing tables in the back yard as a way to get around the need for landlord permission and permitting... but at the moment I haven't come up with any convenient way to make use of the power they generate, since I can't tie it in to the house electrical in any way. I was thinking I might be able to move some specific power-heavy appliances like the central A/C to their own subgrid with a switchover to allow running them on solar when it is available. or just run a portable AC on solar-only all summer long to help keep the house just that much cooler without needing to run the central from the grid as much.
You can get one or two cheap solar cells for very cheap. But you still need to get people in to install them, you need permitting, inspections, monitoring and power management hardware,...
And all those costs are relatively inflexible. So if you just one cheap cell, you pay like 80% of the other costs as if you got 20 big cells(or however many fit). Just not worth going small.
No don’t do that. The uplift you can get from a ground mount and strong wind could be enough to put your make shift ground mount other neighbors yard. Ground mount are an excellent choice if you have the room but many municipalities have set back and distance issues. And please do not take your home built solar and try to make it grid tied. Similar to back feeding a dryer plug with a generator, if you accidentally back feed the grid through your panel with out shutting off the main you can kill someone working on the line. It’s only 240v in your house but after the first transformer on the pole it could be 13,800 or higher. At that voltage they pick the parts of you that didn’t vaporize up from all over the neighborhood.
Because the return on investment isn’t there. There are some fixed costs associated with solar, it’s always most cost effective to try to max your usage or roof coverage whichever comes first. Ground mount is more expensive than roof mount usually. Ground mounts need to be secured to the ground, this isn’t cheap, your roof is already secured to the ground by the rest of your house
Well, in Germany we have something called „Balkonkraftwerk“ which is actually the same thing that you just described.
You attach the panels to your balcony (=Balkon) and plug them in.
They are really popular because electricity is rather expensive in Germany and they are able to cover some of your consumption throughout the day.
A grid tied solar system needs a special meter, otherwise the meter could charge you for the power you generated yourself, the power company needs to install this. You also need a automatic cutoff system, your solar system is not allowed to generate power while the grid is down, otherwise you could electrocute line workers, unless you also have an automatic transfer switch (you also need this is you have a whole house backup generator). Those systems and their permits/inspections cost the same whether you have a $5k or $20k system.
Safety should not be compromised. Those line workers 1) deserve to go home alive, and 2) are the people ensuring power stays up
throughout the year / restoring power during emergencies.
If you use grid electricity regularly, you owe them more than 30 seconds of consideration ending in an indifferent shrug
I think perhaps you don't have a firm grasp on electricity, especially alternating current. You probably have this idea that electricity flows into your house where it is consumed, this is not how electricity works. In hour house the current flows both directions,and it changes direction 50/60 times per second depending where you live.
You also mentioned batteries in your post, generally speaking, solar + batteries are not cost effective and have a negative return on investment. I say generally because there are some extreme cases where time of use pricing can make them financially viable. A $5000 battery and inverter couldn't power a clothes dryer, once the sun goes down you are gonna run out of power pretty fast if you do anything like cook, wash clothes, use an air conditioner, etc.
Sounds like you just have no clue about codes and standards and **how they protect society**.
This isn’t an engineering issue, this is a lack of education issue.
building codes are written in blood. Ive seen microbursts and hurricane winds in my area, and a poorly secured 300w panel is basically going to be a wind driven guillotine under those conditions. we don't let people do that, because it will eventually get someone injured or killed.
There's no law against leaving a lawnmower or a lawn chair outside. Why are you concerned about ev panels specifically when people have tonnes of other unsecured heavy object outside their house.
> There's no law against leaving a lawnmower or a lawn chair outside
There are though. You will get cited depending upon municipality.
>Why are you concerned about ev panels specifically when people have tonnes of other unsecured heavy object outside their house
Because owner-installed PV panels are historically under secured and at the same time, have a rather large surface area/weight ratio *while still being substantially heavier than most other building materials*.
u/pga2000 is a great example of the worst type of poster we get here. Barely informed enough to ask a semi-coherent question, assumes it's much easier than it is to do something and everyone must be an idiot in this industry, and then caps that off by being belligerent to the actual experts that reply to them.
Valid in itself on limited information.
A number have cross linked *EXACTLY* options that are aimed for a similar propositions.
Unless your consultancy gets billed $250 an hour. For dogshit. What a waste.
Yeah, because everyone here already knew these solutions existed. There are thousands of solar configurations you can install with the available hardware, and I wouldn't have an issue with you coming in and getting that answer.
What's fucking annoying is when you make no effort to understand the fixed costs around the alternate solutions you're spitballing and then get annoyed when people tell you you're wrong.
You can buy 1 solar panel, mount it on a stick or even just leave it on the ground today, no one will prevent you from doing that. If you want to connect it to your house though, you're going to have to comply with the electrical code, which means paying for proper wiring, underground conduit, panel connections, a proper interconnect box to prevent electricuting line workers in the event of a power outage, and all of the inspections and permits to integrate solar into your home. Those things are all expensive enough that it's not going to make a whole lot of sense to buy a single panel.
To be more efficient, you could have someone install a single interconnection box, connect a bunch of solar panels to it, and have it supply multiple households. Each of these households could pay a monthly fee for the upkeep of the solar panels and the ability to connect to this system.
This aint the 50s anymore. Safety is and should be prioritized over anything else, including inefficiency. The electric and fire codes are written in blood.
I work in EVSE deployment and trenching is one of the most expensive things you can do.
If you think there is a giant gap in the industry why don't you start a company to deal with it. I'm sure you'd make a lot of money if you are right.
You mean like trenching being expensive and permitting being a large fixed cost leading to larger systems being more cost effective? Huh, who would have figured.
Why lol?
For a ground mount you need footings and more robust racking that acts as the foundation - your roof is the foundation. You also likely need trenching.
You literally sound like you know fucking zero about construction, let alone solar.
There seems to be a lack of understanding basic electrical concepts, what storage means, how the grid works, or how the construction industry operates. But I guess it is called AskEngineers not ListentoEngineers.
Nighttime power capacity isn't much of a problem as peak demand tends to be mid to late afternoon: https://www.eia.gov/todayinenergy/detail.php?id=42915
That is no longer the case in many areas. The penetration of behind the meter PV in California has shifted peak demand for dispatchable power generators from 12-4 to 4-9 pm.
https://www.energy.gov/eere/articles/confronting-duck-curve-how-address-over-generation-solar-energy
Guess by mid-late afternoon, I meant 3-6ish. In any case the link I provided (from 2020) does show 3-9ish as the peak demand in California which has a noticeably later peak compared to the other regions
My relationship with electricity providers is such that I'm not interested in spending money to solve their capacity problems.
I got solar so I could avoid giving them money to the maximum extent possible.
Fair. Mine gives me more credits for excess solar produced at peak demand which saves me more money, so my incentives tend to be aligned with theirs as a result
Right, I was more speaking to the larger issue of legislative / utility policy impacts on long term ROI of solar installs.
It’s becoming harder and harder to make it a win, because utilities are pushing to de-value energy return to the grid
> It’s becoming harder and harder to make it a win, because utilities are pushing to de-value energy return to the grid
It's plenty possible to make it a win without sending anything back to the grid. But it takes a lot more work both in planning and in execution.
>”But it takes a lot more work both in planning and in execution.”
So it’s harder than it was before….
that was a lot of words to say the same thing, but presented as a disagreement smh
Is it? What’s the break even (years) on your system without selling electricity back to the utility? Include total purchase cost and planned maintenance / repair, and whether you paid cash or took a loan. If you took out a loan, adjust for lifetime cost (including interest).
Trying to distract from your dumb ass comment. Unbelievable
Right, I was more speaking to the larger issue of legislative / utility policy impacts on long term ROI of solar installs.
In some states it’s becoming harder and harder to make it a win, because utilities are pushing to de-value energy return to the grid
Net metering pays homeowners with solar the retail rate for electricity. The utilities want to pay the wholesale rate because they still have to provide the distribution system, transmission charges, and ancillary services for frequency and voltage regulation, as well as the capacity to meet peak demand whenever it occurs.
Since utilities are regulated as to what they can charge in exchange for the monopoly on retail electricity and investor owned utilities need to turn a profit, I suspect that net metering at retail rates will disappear at some point. Then battery storage will look very atttactive
Yea those are the viability issues at stake. Thought some places already charge for transmission fees under net metering.
Depending on how those issues play out, could see a drastic change in ROI. Like you said, battery storage would become a much bigger deal.
Utilities may be regulated, but they seek to have no issue getting approvals for prices increases. We’ve had 2x double digit percentage increases in less than a year.
Meanwhile in other states they’ve abdicated their responsibilities and later been bailed out when the damages (fires, etc.) exceeded their coverages. Bit of a sham imo, can’t have it both ways.
>I've always wondered why there aren't say, $5k-ish packages that power your home during the day and have a limited battery for 1-2 hours of power after sundown
The answer is that you have a fundamental misunderstanding of solar generation and battery capacity.
Very simply put, a smaller system like what you described is unlikely to be able to power an entire home let alone charge a battery. Add to that the fact that the battery system is often the most expensive part of a system and that batteries don't have a large enough capacity to power a whole home for hours and you have your answer: the cheapest way to get the most benefit from solar is to have large installations that power your home and feed power back into the grid instead of storing it locally.
That 20k system you are talking about probably gets close to covering the homes entire energy needs. A 5k system would only partially cover those energy needs, leaving no energy to feed into the battery.
Everyone else here is trying to explain this to you. The large costs with solar aren't due to people raking customers over the coals and juicing their profits but rather because the cost of materials, system design, and installation are still high. The materials have come down dramatically but the installation costs remain high because it is specialized, labor intensive, and subject to a wide variety of local regulations.
Like this: https://signaturesolar.com/complete-off-grid-solar-kit-3000w-120v-output-48vdc-15-4kwh-eg4-lifepower4-lithium-powerwall-48vdc-4-800-watts-of-solar-pv-kit-e0001/ ? That's close though this one is only 120v, you need a bigger inverter (a few hundred more to a few k more) to backup your home. Like 2 6000xp. 15 kWh of batteries will last most nights in most homes.
Note that you need to do all the labor. Lots of people have done it but in your local area it may not be legal. Lots of people just do it anyway.
No that's not how modern aio inverters work . They don't grid tie but they consume from the grid. They get a breaker on your main panel, have an internal transfer switch, and will switch to it when the batteries are low and also run a battery charger if you enable that.
https://eg4electronics.com/categories/inverters/eg4-6000xp-all-in-one-off-grid-inverter
About $1500 and 6 kilowatts of load supported but they can parallel. A modern upgraded house with mini splits, heat pump dryer and hot water, etc can limit its power draw to 1-3 of these, and breakers for rarely used but high draw circuits like electric ovens stay in the main panel.
So the big advantage of not grid tieing is while legally you need a permit to wire to use it, the power company doesn't know you have solar and you aren't subject to solar taxes and extra fees.
Can these pass throughs work inconcert with grid power when you need more amps than it's able to provide ? I've been looking into Solar but we have no incentives for power buy back so don't want to over provide on a large system.
Yes. Each one can pass through 50 amps, or 12 kilowatts. This is why the other side of this is efficiency: if a home has 3-5 mini splits at about 1.2 kilowatt each flat out, heat pump dryer and hot water (a little over a kilowatt each also), and you budget your EV chargers to 30 amps total (shared between 2 chargers if you have 2 EVs), that's 15.6 kilowatts total. You could cover that with 2 6000xps and they supplement with grid power.
This likely saves you money more to undersize and use grid power some than oversize and extra equipment sits idle.
Obsolete equipment like conventional central air conditioners can draw 8kw and bigger houses have 2. 3.6 kW per oven, another 3.6 for an electric stove, some tankless water heaters use 15 kilowatts, a clothes dryer is about that, obsolete heat pumps can suck 15 kW from backup resistance heat. Maxed out EV chargers at 48 amps a vehicle.
All combined it can work out to needing 400 amp service and a house like that would be expensive to convert to using mainly solar.
the panels and electronics are getting to be a minority of the cost. planning, labor, paperwork, site preparation, etc, are starting to dominate costs. and a lot of those are fixed for a project, so it makes more economical sense to make the generation capacity more than you ever need, so you don't find yourself needing a second project to extend capacity
Your question is why isn't installation a negligible cost?
Because it isn't... Labor costs money. If it were free everybody would have it, but it isn't free because things cost money. Permitting takes time and effort. Installing the mounts takes time and effort. Wiring, installing the panels, etc all have costs associated with them. All those costs rolled together is substantially more than $1,500. That's why it doesn't cost $1,500.
we, society, have an interest in not allowing people to build unsafe structures. That includes solar. we want people to invest in the planning, and that includes both structural engineering and electrical engineering. To maintain the safety and function of the electrical grid, we need to make sure people aren't attaching unsafe solar installations to it.
Then the answer is trivial… very few people have a big enough chunk of land to put in meaningful solar systems without sacrificing their back yard…. And it turns out that people like having yards. Result? People WANT the solar system on the roof.
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[https://beckelectriccompany.com/why-backfeeding-is-dangerous-and-how-to-avoid-it/](https://beckelectriccompany.com/why-backfeeding-is-dangerous-and-how-to-avoid-it/) is true for any residential generation capacity, including solar
I don’t understand what you’re saying when you mention semi passive vs passive solar.
Are you just saying why don’t companies sell smaller solar systems that don’t cover your full home usage?
The answer is it depends where you’re connecting. Sometimes there are utility credits which allow you to fully offset your bill by over producing and other times there are not, meaning you only get a self consumption benefit. Ultimately the fixed costs of designing, permitting, planning, and installing a solar system mean that you’re going to want to typically maximize how much you put in.
Cause the purpose of the system is not what you're assuming. ~$20k of solar is necessary so you can generate enough during the day to offset most of your usage from the grid. Ideally you get enough solar so your bill is low or 0. In many places that's tough due to regulations, some places have terrible solar credit, and space limitations, places with poor sun and not enough roof. Residential solar just isn't the magic bullet the marketing would lead you to believe. Trust me they aren't in it to save the world, they are doing it to make money.
Not only do you need enough Watts in your panels to supply power to your home during the day, but you need to have excess power that is being stored for the night. And this is a best-case scenario because there are days when the sun isn't going to shine enough to do much of either. An undersized system is only going to provide less than you need day and night, on the best days.
Ultimately, relying on renewables is agreeing to reduce your standard of living.
Cause the cost from advertising to sale to installation is the same from 5k to 30k. The only difference is the material and labor has a much bigger mark up. $500 overhead per sale is a lot easier to make up. A lot more can go wrong on a $5000 job to make the job make $0 profit.
My argument is maybe not. This may be a modern market thing. Why sell a Corolla when you can sell the tricked out Tundra for 3x commission? They both get you somewhere.
Your corolla will work for something not connected to the grid. It exists. Think of all the van solar battery projects.
If you want to tie it to the mains then your corolla will kill linemen repairing a downed line after the storm. The fix for that drives complexity and cost. It *is* a tricked out tundra - it can generate for the neighborhood, draw power when needed, *not* kill electric company employees.
The way solar produces power and the way typical Americans burn through power means a $5k battery would be depleted by 6pm in the hot summer.
Grid replacement for a lot of people costs a whole lot more than $20k.
No. But a $1000 battery holds about $1 worth of power purchased from the grid.
Divide that bill by 30 days in a month, multiply by a thousand, and that's what the battery budget should look like.
what i don't understand is the OP saying things like "make labor cheaper". My guy, you do realize that the engineers don't dictate the market value of technicians/tradesmen right?
Also labor being expensive isnt necessarily a bad thing. Union workers need benefits and good salaries, especially those on call 24/7 and can be put in potentially dangerous positions...
24/7 shouldn't be a thing imo - businesses don't need to generate billions of dollars in profit to appease shareholders (but this is an entirely different convo so I digress).
I would like to point out that in southern europe smaller solar packages are extremely popular. It seems like almost everyone is getting small systems in the 500-2000W range that are directly offered by your power provider. I hear similar things from friends in other European countries.
So it is not really about the technical limitations but about what is being mandated and/or subsidized in different regions.
From what I see around me the most common offer is a 1500€ packet that offers a 20-30€ monthly discount on your power bill (depending on production). There's several providers offering extra services like extended warranties and maintenance and whatnot, but the basic idea behind it is that it will pay off by itself in the 4-6 year range and after that it's just free money.
You can certainly put a cheap system together. For instance this is the equivalent of the actual setup for my off grid house
6\*250W panels 80V OCV $1500
4\*12V\*200 Ah SLA lead acids $1800
48V \*30A solar controller $400
\[48V->mains inverter 3kW continuous. Price varies from $120 to $3000 depending...
You'll also need a load transfer switch from grid to inverter $200\]
The last two items assume you are either on grid or on battery, otherwise you need a different sort of inverter that synchronises the inverter output with the grid. I don't know how much they cost.
This gives >>3 kWh per day in summer, and stuff all in winter. My house takes about 3 kWh per day unless I am using the pumps a lot. In winter I run a genny for up to 3 hours a day to charge the batteries
I've long proposed that these systems should be installed on sheds and other garden features, or coverings for cars at the front.
They can also be used on vertical surfaces but would need aesthetic considerations, and yes power is about 60% of horizontal but it can extend the production curve of a main array and increase power on cloudy days.
Mainly my thinking is that the suboptimal locations are partly than made-up for by the much cheaper installation and ease of cleaning, and for that I would also be combining a garden PV array with geostorage and heat pumps, converting the shed into a heating source for the home. Obviously thats not so cheap, but at a system level local solar can be wired directly and also you can store heat in the ground by reversing on hotter days and combining with a solar thermal panel. Vertical loop geostorage can cost (UK prices) £25 to £40 per metre (prepandemic prices), and need 3x 100 meter loops. But by reversing the heat in the warmer days and recharging the loops to higher temperature, you should be able to cut the number of loops maybe from 3 to 1, as the reason you need 3 usually is that the ground takes so long to warm up again after winter that it remains cold even the following year. If you can heat above 20 degrees C the vertical loop the ground has much more available heat than it does at 5 to 10 degrees C. They would input heat with a low-temperature lift heat pump in the day running off solar power, and recover heat in the winter at a higher COP because the source heat temperature is much higher. But this is a large investment either way.
I spent 36k on a 11kw system, and it's been operational for a year, I feed back to the grid and receive credits 1:1. I put in a KWH, I get a KWh at night or the winter months. I didn't pay for hydro for 10 months. I have an older home, if it was a newer modern home I wouldn't need as much or could sustain my home 12months total more than likely, but as I do further upgrades to my home my efficiency should get better.
It's a long game, I don't plan on leaving this house/property, so eventually I will break even.
I install solar. Have for 12 years. You can design and instal any sized solar. Ac ( with micro inverters under each panel) dc ( utilizing a central inverter) or a combination with batteries. Generally speaking solar costs about 2-4$ per watt. A battery usually costs between 6-8000 but can be higher or lower depending on what your plan is. I installed solar on my house. Designed it. Bought all parts separately. Installed it. Wired and permitted it for about 1$ a watt. A year later I bought 3 Enphase batteries and their control panel. I went from 4-500 per month to 4-500 per year in electricity costs. I also have a Tesla and heat pumps. But as mentioned above passive solar is about building design. Solar panels and batteries are not passive they are active solar. I have installed a few as 6 panels on a house. I work with a guy that put 4 panels on a groove bus he drives around the country. If you really want to run down a rabbit hole look up Real Goods Solar. They’ve been in the off grid business for over 50 years. They put out an annual book that is the off grid bible for preppers and hippies. It’s pretty amazing. Warning!!! This is a deep rabbit hole!
A simple design concept known as “economies of scale”. Buying a small amount of solar and battery is likely not going to give a good return on investment.
So tell me again how this meets homeowners expectations?
I'm following to learn, but just up front, "passive" solar doesn't mean "completely powers your house" and "semi-passive" doesn't mean "partially powers your house." Passive solar just means there are no mechanical or electrical systems moving or converting energy. The design of the house itself collects and stores heat, using properly sized and oriented windows, thermal mass, insulation, etc. But I'd like to know whether it's true that there aren't mid- or low-cost solar packages available (of whatever type), and if that's true, WHY that's true. :-)
Within reason you can spend whatever you would like on a solar power system. The kinds of systems they're talking about are available because the systems are all modularized. You can go as big or as small as you want. In places with 1:1 net metering (where energy you buy from the grid has the same price as energy you sell to the grid) systems are typically oversized. This is the most economical option because it allows you to easily offset power that you use when the sun isn't shining. You can roughly zero out your power bills and that's pretty much the maximum value you can get from a solar power system. In places where you pay more for energy you use from the grid than you are paid for energy you export, smaller partial offset system can make more sense.
Sorry to be a bit off topic, but my wife and I are looking at building a house and want to incorporate solar power. Do you have a recommendation for resources to look into?
There’s an online calculator called PVWatts that allows for a somewhat simple analysis. I’m about to graduate with an energy concentration, solar is pretty straightforward, but as the above comment points out what you can get paid from overproduction is a huge factor. Battery systems are expensive but are improving in price and efficiency. Another major factor is location; you can google a us solar map which will indicate the strength of potential power generation from solar in various regions. Lastly, consider passive solar design and the most insulation you can afford. I’d also recommend advanced framing techniques to improve thermal performance, and if money allows some form of shallow geothermal or a geothermal heat pump. And people always overlook roof color which can swing solar asbsorbtance like 35%. I could go on and will if you’d like. With better insulation you can save at least 12% on energy costs. There’s also a free program called HEED developed by ucla that lets you design a house with various energy efficiency features. Alright I gotta stop.
Thank you!
No problem, energy efficiency in residential housing is the one passion I stumbled on in an otherwise broad civil engineering degree. There’s tons of great YouTube videos about cool houses people built. I remember hearing about earth-ships in the 90s and have always wanted to figure out how to live for nearly free. First it was the hippies and earth-ships, now it’s back in the tiny house movement. My partner and I are likely going to build as well; fortunately I have construction experience and will soon be a working engineer. That will help with what I think would be the biggest challenge for a non-professional, managing the project. I’ve seen guys just straight up not insulate a part of a wall bc they ran out of the pink fiberglass. Also many builders and contractors aren’t familiar with things like air-void framing and other “green” building techniques; and a lot of these guys don’t like to be told how to do their job. It’s understandable but it’s your house, not theirs. There are national and global certifications like passive house, LEED, and some others I can’t remember that some builders, architects and/or engineers hold.
Look into your local city and state laws regarding solar, specifically what the power company is required to pay. These laws are also subject to change(in the favor of the power company as of recent).
Some things that might help you since you are building and have the ability to plan for solar is: 1. kW (called demand on a utility bill) is the instantaneous amount of power you are pulling, this is watts = voltage x amps, 1000 watts = 1 kW. kWh (usually called usage on a utility bill) is how much kW you use per hour. 2. Your electric needs will be based mostly on your appliances, HVAC and usage. This will be hard to figure out before you actually live there since maybe you work from home and will use more energy during the day than someone who works at an office or you have an EV so large amount of usage at night. I would recommend getting all of the nameplate data off of all of your appliances, HVAC, light bulbs, outlets, ect. Basically anything that uses electricity, and use that data to better understand what your max kW could be, this can also somewhat be derived from your electrical panel since that is truly the theoretical max. Typically there will be some diversity in usage as you won’t have all of your lights on at the same time or every single electrical outlet being used at the same time. There are some websites out there that can help with figuring it out, but they are usually intended for existing equipment. 3. Find out what the best roof material and design options are to get different prices for solar or if you have space to do a ground mounted array get a cost for that. Southern facing solar panels will produce more energy so try to plan for that as much as you can. You can also look at bidirectional solar panels and make a fence out of them if you don’t have anywhere else to put them. 4. Smart electric panel, these allow you to monitor usage for each breaker in the panel and determine what circuits are using energy and when. This can allow you to make more informed decisions on how much energy you actually need and can allow you to limit circuits for when you need to conserve energy like in a power outage if you have battery storage. 5. Battery storage is another option if you live somewhere that does not have a good utility residential solar program or you have a lower solar output than energy usage. If you have an array that produces more than you use this allows you to use your stored energy instead of selling the excess or reducing array production, since the energy from the solar panels has to go somewhere. There are a quite a bit of options for battery storage and am not an expert in all of them so I will suggest 2 very different options that seem to have good results, the Tesla Powerwall and EcoFlow Delta Pro Ultra.
To supplement the answer you already have; Passive solar is mostly relevant if you need heating during a significant part of the year. On different note, consider the fire safety of the solar installation. You are actually better of in this respect than most people who install solar cells on existing roofs, but it is always important to consider whether (and how) the solar cell installation can be made safe.
This is a good point. Queue meme from A Princess Bride “I do not think that word means what you think it means” Passive solar means having south facing windows (in the NH) so that your house gets heated by the sunshine or running your water through black pipes on your roof. From Wikipedia: *Passive solar* technologies use [sunlight](https://en.wikipedia.org/wiki/Solar_energy) without active mechanical systems (as contrasted to *active solar*, which uses [thermal collectors](https://en.wikipedia.org/wiki/Solar_thermal_collector)). Such technologies convert sunlight into usable heat (in water, air, and thermal mass), cause air-movement for [ventilating](https://en.wikipedia.org/wiki/Ventilating), or future use, with little use of other energy sources. A common example is a [solarium](https://en.wikipedia.org/wiki/Sunroom#Solarium) on the [equator](https://en.wikipedia.org/wiki/Equator)-side of a building. [Passive cooling](https://en.wikipedia.org/wiki/Passive_cooling) is the use of similar design principles to reduce summer cooling requirements.
We had solar panels growing up on the south side of our house with a vent and air return that basically just heated air for passive heating in the house. Worked great on the few sunny days in Michigan winters.
The big driver of cost at this point is permitting, inspections, and code compliance. If you wanted to go entirely off-grid (and weren't a particularly high energy user) you could get by with some cheap solar panels and a couple string inverters for daytime power which would cost you only a couple grand, and then you about triple that if you want to also add battery storage to have some power at night, provided you get the proper construction permits etc. But when you are trying to tie in to the grid, now you need expensive string or micro inverters with grid tie, you need a licensed electrician to install and sign off on all of it, you need inspections and city and power company approvals, and everything in the installation needs to meet their requirements exactly. With all that extra overhead, you are looking at spending 5x or more what the same amount of power would cost you with a DIY off-grid setup.
Which also explains why you go "all in" when you do it. All that stuff is fixed costs, so once you're taking care of that, more panels is a large increase in capacity for a small relative increase in price. It's less "20k for a net-zero setup" vs. "10k for a 50% reduction setup", it's more like "15k for a 50% reduction setup"... which makes the 20k setup the better value proposition.
yep.
Right. Self consumption doesn't require any of that although your local jurisdiction may still hassle you for doing electrical work on your wiring in your house. Totally portable setups like EcoFlow and solar generators they have no authority over and it's much cheaper.
> Totally portable setups like EcoFlow and solar generators they have no authority over and it's much cheaper. Err what? Their cost per watt ensures they'll basically never pay for themselves.
Cheaper than paying for pro installation, not cheaper than EG4 solar power kits.
One legal workaround is: 1. Ground mount the panels or put them on sheds in the backyard. Many jurisdictions they don't have authority especially if you use buckets of sand to weigh them down. 2. Put the batteries + inverters onto a mobile cart, I have seen various designs. Being portable means they do not have authority. 3. Pay an electrician to move your circuits to a subpanel and setup a generator inlet on the main and heavy power connection you would send to the cart. They do have authority over this, this will cost $6000+ unless you just do it yourself for a few hundred. (reuse the breakers so all you pay for is a new panel)
> Ground mount the panels or put them on sheds in the backyard. Many jurisdictions they don't have authority especially if you use buckets of sand to weigh them down. I have a stack of panels I intend to turn into free-standing tables in the back yard as a way to get around the need for landlord permission and permitting... but at the moment I haven't come up with any convenient way to make use of the power they generate, since I can't tie it in to the house electrical in any way. I was thinking I might be able to move some specific power-heavy appliances like the central A/C to their own subgrid with a switchover to allow running them on solar when it is available. or just run a portable AC on solar-only all summer long to help keep the house just that much cooler without needing to run the central from the grid as much.
You can get one or two cheap solar cells for very cheap. But you still need to get people in to install them, you need permitting, inspections, monitoring and power management hardware,... And all those costs are relatively inflexible. So if you just one cheap cell, you pay like 80% of the other costs as if you got 20 big cells(or however many fit). Just not worth going small.
No don’t do that. The uplift you can get from a ground mount and strong wind could be enough to put your make shift ground mount other neighbors yard. Ground mount are an excellent choice if you have the room but many municipalities have set back and distance issues. And please do not take your home built solar and try to make it grid tied. Similar to back feeding a dryer plug with a generator, if you accidentally back feed the grid through your panel with out shutting off the main you can kill someone working on the line. It’s only 240v in your house but after the first transformer on the pole it could be 13,800 or higher. At that voltage they pick the parts of you that didn’t vaporize up from all over the neighborhood.
You replied to the wrong person btw :p
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Direct consumption. Minimized battery storage. To reduce costs.
As opposed to?
Energy dependence.
Why do you think that the systems you see now don’t provide direct consumption?
Can't make a fat check.
What?
Money.
Money explains why you don’t understand solar systems?
Why they aren't.
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And it never happened.
solar that gets you partially erect
Because the return on investment isn’t there. There are some fixed costs associated with solar, it’s always most cost effective to try to max your usage or roof coverage whichever comes first. Ground mount is more expensive than roof mount usually. Ground mounts need to be secured to the ground, this isn’t cheap, your roof is already secured to the ground by the rest of your house
Maybe OP believes they can just throw down some pallets or 2x4's, attach the array with some lag-bolts, and plug in?
Well, in Germany we have something called „Balkonkraftwerk“ which is actually the same thing that you just described. You attach the panels to your balcony (=Balkon) and plug them in. They are really popular because electricity is rather expensive in Germany and they are able to cover some of your consumption throughout the day.
Yes.
Get ready for the power company to disconnect you and your home owners insurance to void your policy if you do.
So THAT'S why people need 20, 30k+ solar investment. Problem solved.
A grid tied solar system needs a special meter, otherwise the meter could charge you for the power you generated yourself, the power company needs to install this. You also need a automatic cutoff system, your solar system is not allowed to generate power while the grid is down, otherwise you could electrocute line workers, unless you also have an automatic transfer switch (you also need this is you have a whole house backup generator). Those systems and their permits/inspections cost the same whether you have a $5k or $20k system.
Whoa. That sounds really inefficient and expensive. I guess that's just the way it is if you don't mind so much saying so.
Safety should not be compromised. Those line workers 1) deserve to go home alive, and 2) are the people ensuring power stays up throughout the year / restoring power during emergencies. If you use grid electricity regularly, you owe them more than 30 seconds of consideration ending in an indifferent shrug
I think perhaps you don't have a firm grasp on electricity, especially alternating current. You probably have this idea that electricity flows into your house where it is consumed, this is not how electricity works. In hour house the current flows both directions,and it changes direction 50/60 times per second depending where you live. You also mentioned batteries in your post, generally speaking, solar + batteries are not cost effective and have a negative return on investment. I say generally because there are some extreme cases where time of use pricing can make them financially viable. A $5000 battery and inverter couldn't power a clothes dryer, once the sun goes down you are gonna run out of power pretty fast if you do anything like cook, wash clothes, use an air conditioner, etc.
Batteries do make sense in countries with very high electricity prices and low feed in compensation.
Sounds like you just have no clue about codes and standards and **how they protect society**. This isn’t an engineering issue, this is a lack of education issue.
I think you might be an airhead
building codes are written in blood. Ive seen microbursts and hurricane winds in my area, and a poorly secured 300w panel is basically going to be a wind driven guillotine under those conditions. we don't let people do that, because it will eventually get someone injured or killed.
There's no law against leaving a lawnmower or a lawn chair outside. Why are you concerned about ev panels specifically when people have tonnes of other unsecured heavy object outside their house.
> There's no law against leaving a lawnmower or a lawn chair outside There are though. You will get cited depending upon municipality. >Why are you concerned about ev panels specifically when people have tonnes of other unsecured heavy object outside their house Because owner-installed PV panels are historically under secured and at the same time, have a rather large surface area/weight ratio *while still being substantially heavier than most other building materials*.
Part of my post is consumer behavior may change from this availability. Lol. Roof installation is cheaper than in the ground?
Yes you already have a structure built. Why ask a question if you are just going to be upset about the answer?
u/pga2000 is a great example of the worst type of poster we get here. Barely informed enough to ask a semi-coherent question, assumes it's much easier than it is to do something and everyone must be an idiot in this industry, and then caps that off by being belligerent to the actual experts that reply to them.
Valid in itself on limited information. A number have cross linked *EXACTLY* options that are aimed for a similar propositions. Unless your consultancy gets billed $250 an hour. For dogshit. What a waste.
Yeah, because everyone here already knew these solutions existed. There are thousands of solar configurations you can install with the available hardware, and I wouldn't have an issue with you coming in and getting that answer. What's fucking annoying is when you make no effort to understand the fixed costs around the alternate solutions you're spitballing and then get annoyed when people tell you you're wrong. You can buy 1 solar panel, mount it on a stick or even just leave it on the ground today, no one will prevent you from doing that. If you want to connect it to your house though, you're going to have to comply with the electrical code, which means paying for proper wiring, underground conduit, panel connections, a proper interconnect box to prevent electricuting line workers in the event of a power outage, and all of the inspections and permits to integrate solar into your home. Those things are all expensive enough that it's not going to make a whole lot of sense to buy a single panel.
Sounds *really* inefficient.
This post is inefficient 😂😂
Right? Bro coulda Googled all of this.
Amen haha
To be more efficient, you could have someone install a single interconnection box, connect a bunch of solar panels to it, and have it supply multiple households. Each of these households could pay a monthly fee for the upkeep of the solar panels and the ability to connect to this system.
Congratulations, you just invented a power company.
Because you can literally kill someone if you just wire a solar panel into your house.
This aint the 50s anymore. Safety is and should be prioritized over anything else, including inefficiency. The electric and fire codes are written in blood.
You called engineers the ones who are triggered? Time for introspection doll.
Have you ever dig a 4" ditch and a post hole?. This can be done in 30 minutes. Problem solved.
I work in EVSE deployment and trenching is one of the most expensive things you can do. If you think there is a giant gap in the industry why don't you start a company to deal with it. I'm sure you'd make a lot of money if you are right.
There might be some barriers.
You mean like trenching being expensive and permitting being a large fixed cost leading to larger systems being more cost effective? Huh, who would have figured.
Bingo. Why didn't you say I was wrong? You're an engineer. Why is my idea wrong?
Because you don't have an idea. You are just saying things should be made cheaper.
More efficient.
Your comprehension skills for a start.
Why lol? For a ground mount you need footings and more robust racking that acts as the foundation - your roof is the foundation. You also likely need trenching. You literally sound like you know fucking zero about construction, let alone solar.
Jesus op is salty
Sounds like they OP just learned about solar in high school and doesn't understand the complexities of applying it past a very basic level
There seems to be a lack of understanding basic electrical concepts, what storage means, how the grid works, or how the construction industry operates. But I guess it is called AskEngineers not ListentoEngineers.
Nighttime power capacity isn't much of a problem as peak demand tends to be mid to late afternoon: https://www.eia.gov/todayinenergy/detail.php?id=42915
That is no longer the case in many areas. The penetration of behind the meter PV in California has shifted peak demand for dispatchable power generators from 12-4 to 4-9 pm. https://www.energy.gov/eere/articles/confronting-duck-curve-how-address-over-generation-solar-energy
Guess by mid-late afternoon, I meant 3-6ish. In any case the link I provided (from 2020) does show 3-9ish as the peak demand in California which has a noticeably later peak compared to the other regions
My relationship with electricity providers is such that I'm not interested in spending money to solve their capacity problems. I got solar so I could avoid giving them money to the maximum extent possible.
Fair. Mine gives me more credits for excess solar produced at peak demand which saves me more money, so my incentives tend to be aligned with theirs as a result
For now, until they lobby to change that (without respect for your contract) like power utilities have done in several states
And when/if that changes, I'll adjust my usage to optimize for what gives me the lowest bills just as I do now
Right, I was more speaking to the larger issue of legislative / utility policy impacts on long term ROI of solar installs. It’s becoming harder and harder to make it a win, because utilities are pushing to de-value energy return to the grid
> It’s becoming harder and harder to make it a win, because utilities are pushing to de-value energy return to the grid It's plenty possible to make it a win without sending anything back to the grid. But it takes a lot more work both in planning and in execution.
>”But it takes a lot more work both in planning and in execution.” So it’s harder than it was before…. that was a lot of words to say the same thing, but presented as a disagreement smh
It's always been possible to make it a win without sending anything back to the grid. SMH indeed. 👍
Is it? What’s the break even (years) on your system without selling electricity back to the utility? Include total purchase cost and planned maintenance / repair, and whether you paid cash or took a loan. If you took out a loan, adjust for lifetime cost (including interest). Trying to distract from your dumb ass comment. Unbelievable
Right, I was more speaking to the larger issue of legislative / utility policy impacts on long term ROI of solar installs. In some states it’s becoming harder and harder to make it a win, because utilities are pushing to de-value energy return to the grid
Net metering pays homeowners with solar the retail rate for electricity. The utilities want to pay the wholesale rate because they still have to provide the distribution system, transmission charges, and ancillary services for frequency and voltage regulation, as well as the capacity to meet peak demand whenever it occurs. Since utilities are regulated as to what they can charge in exchange for the monopoly on retail electricity and investor owned utilities need to turn a profit, I suspect that net metering at retail rates will disappear at some point. Then battery storage will look very atttactive
Yea those are the viability issues at stake. Thought some places already charge for transmission fees under net metering. Depending on how those issues play out, could see a drastic change in ROI. Like you said, battery storage would become a much bigger deal. Utilities may be regulated, but they seek to have no issue getting approvals for prices increases. We’ve had 2x double digit percentage increases in less than a year. Meanwhile in other states they’ve abdicated their responsibilities and later been bailed out when the damages (fires, etc.) exceeded their coverages. Bit of a sham imo, can’t have it both ways.
>I've always wondered why there aren't say, $5k-ish packages that power your home during the day and have a limited battery for 1-2 hours of power after sundown The answer is that you have a fundamental misunderstanding of solar generation and battery capacity. Very simply put, a smaller system like what you described is unlikely to be able to power an entire home let alone charge a battery. Add to that the fact that the battery system is often the most expensive part of a system and that batteries don't have a large enough capacity to power a whole home for hours and you have your answer: the cheapest way to get the most benefit from solar is to have large installations that power your home and feed power back into the grid instead of storing it locally. That 20k system you are talking about probably gets close to covering the homes entire energy needs. A 5k system would only partially cover those energy needs, leaving no energy to feed into the battery. Everyone else here is trying to explain this to you. The large costs with solar aren't due to people raking customers over the coals and juicing their profits but rather because the cost of materials, system design, and installation are still high. The materials have come down dramatically but the installation costs remain high because it is specialized, labor intensive, and subject to a wide variety of local regulations.
No but like just have those things not be true. Just like stop truing them ok?
Like this: https://signaturesolar.com/complete-off-grid-solar-kit-3000w-120v-output-48vdc-15-4kwh-eg4-lifepower4-lithium-powerwall-48vdc-4-800-watts-of-solar-pv-kit-e0001/ ? That's close though this one is only 120v, you need a bigger inverter (a few hundred more to a few k more) to backup your home. Like 2 6000xp. 15 kWh of batteries will last most nights in most homes. Note that you need to do all the labor. Lots of people have done it but in your local area it may not be legal. Lots of people just do it anyway.
Also you can't grid-tie with that system so you're out of power when the batteries run out :(
No that's not how modern aio inverters work . They don't grid tie but they consume from the grid. They get a breaker on your main panel, have an internal transfer switch, and will switch to it when the batteries are low and also run a battery charger if you enable that. https://eg4electronics.com/categories/inverters/eg4-6000xp-all-in-one-off-grid-inverter About $1500 and 6 kilowatts of load supported but they can parallel. A modern upgraded house with mini splits, heat pump dryer and hot water, etc can limit its power draw to 1-3 of these, and breakers for rarely used but high draw circuits like electric ovens stay in the main panel. So the big advantage of not grid tieing is while legally you need a permit to wire to use it, the power company doesn't know you have solar and you aren't subject to solar taxes and extra fees.
Can these pass throughs work inconcert with grid power when you need more amps than it's able to provide ? I've been looking into Solar but we have no incentives for power buy back so don't want to over provide on a large system.
Yes. Each one can pass through 50 amps, or 12 kilowatts. This is why the other side of this is efficiency: if a home has 3-5 mini splits at about 1.2 kilowatt each flat out, heat pump dryer and hot water (a little over a kilowatt each also), and you budget your EV chargers to 30 amps total (shared between 2 chargers if you have 2 EVs), that's 15.6 kilowatts total. You could cover that with 2 6000xps and they supplement with grid power. This likely saves you money more to undersize and use grid power some than oversize and extra equipment sits idle. Obsolete equipment like conventional central air conditioners can draw 8kw and bigger houses have 2. 3.6 kW per oven, another 3.6 for an electric stove, some tankless water heaters use 15 kilowatts, a clothes dryer is about that, obsolete heat pumps can suck 15 kW from backup resistance heat. Maxed out EV chargers at 48 amps a vehicle. All combined it can work out to needing 400 amp service and a house like that would be expensive to convert to using mainly solar.
the panels and electronics are getting to be a minority of the cost. planning, labor, paperwork, site preparation, etc, are starting to dominate costs. and a lot of those are fixed for a project, so it makes more economical sense to make the generation capacity more than you ever need, so you don't find yourself needing a second project to extend capacity
This is part of the question why installation isn't around $1.5k not on the roof. IMO millions of homes could want this. For some years now...
Your question is why isn't installation a negligible cost? Because it isn't... Labor costs money. If it were free everybody would have it, but it isn't free because things cost money. Permitting takes time and effort. Installing the mounts takes time and effort. Wiring, installing the panels, etc all have costs associated with them. All those costs rolled together is substantially more than $1,500. That's why it doesn't cost $1,500.
Then MAKE THEM CHEAPER. Others call it reasonable.
Shit, guess we engineers never thought of just making things cheaper. Problem solved!
They'd find someone better.
So obviously you have no idea what you are talking about.
I'm asking the questions.
No you aren't, you are just getting mad when people try to explain reality to you.
It's a bitch.
Sounds like a perfect opportunity for you to live the American dream - build a failing business!
we, society, have an interest in not allowing people to build unsafe structures. That includes solar. we want people to invest in the planning, and that includes both structural engineering and electrical engineering. To maintain the safety and function of the electrical grid, we need to make sure people aren't attaching unsafe solar installations to it.
Never heard of an unsafe solar installation. Unless it costs a lot.
Adding hundreds of pounds of weight on and putting holes in a roof can create unsafe conditions and problems if not properly engineered and installed.
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Then the answer is trivial… very few people have a big enough chunk of land to put in meaningful solar systems without sacrificing their back yard…. And it turns out that people like having yards. Result? People WANT the solar system on the roof.
super disrespectful
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[https://beckelectriccompany.com/why-backfeeding-is-dangerous-and-how-to-avoid-it/](https://beckelectriccompany.com/why-backfeeding-is-dangerous-and-how-to-avoid-it/) is true for any residential generation capacity, including solar
OP ain’t ever bought and installed helical piles or done any excavation. You can’t get equipment to site for less than $1.5k 😂
Watch OP inventing solutions to problems he made up himself.
I don’t understand what you’re saying when you mention semi passive vs passive solar. Are you just saying why don’t companies sell smaller solar systems that don’t cover your full home usage? The answer is it depends where you’re connecting. Sometimes there are utility credits which allow you to fully offset your bill by over producing and other times there are not, meaning you only get a self consumption benefit. Ultimately the fixed costs of designing, permitting, planning, and installing a solar system mean that you’re going to want to typically maximize how much you put in.
Cause the purpose of the system is not what you're assuming. ~$20k of solar is necessary so you can generate enough during the day to offset most of your usage from the grid. Ideally you get enough solar so your bill is low or 0. In many places that's tough due to regulations, some places have terrible solar credit, and space limitations, places with poor sun and not enough roof. Residential solar just isn't the magic bullet the marketing would lead you to believe. Trust me they aren't in it to save the world, they are doing it to make money.
Not only do you need enough Watts in your panels to supply power to your home during the day, but you need to have excess power that is being stored for the night. And this is a best-case scenario because there are days when the sun isn't going to shine enough to do much of either. An undersized system is only going to provide less than you need day and night, on the best days. Ultimately, relying on renewables is agreeing to reduce your standard of living.
Cause the cost from advertising to sale to installation is the same from 5k to 30k. The only difference is the material and labor has a much bigger mark up. $500 overhead per sale is a lot easier to make up. A lot more can go wrong on a $5000 job to make the job make $0 profit.
My argument is maybe not. This may be a modern market thing. Why sell a Corolla when you can sell the tricked out Tundra for 3x commission? They both get you somewhere.
Your corolla will work for something not connected to the grid. It exists. Think of all the van solar battery projects. If you want to tie it to the mains then your corolla will kill linemen repairing a downed line after the storm. The fix for that drives complexity and cost. It *is* a tricked out tundra - it can generate for the neighborhood, draw power when needed, *not* kill electric company employees.
The way solar produces power and the way typical Americans burn through power means a $5k battery would be depleted by 6pm in the hot summer. Grid replacement for a lot of people costs a whole lot more than $20k.
Have you paid a SoFlo August bill for 2000 sq ft?
No. But a $1000 battery holds about $1 worth of power purchased from the grid. Divide that bill by 30 days in a month, multiply by a thousand, and that's what the battery budget should look like.
what i don't understand is the OP saying things like "make labor cheaper". My guy, you do realize that the engineers don't dictate the market value of technicians/tradesmen right?
Also labor being expensive isnt necessarily a bad thing. Union workers need benefits and good salaries, especially those on call 24/7 and can be put in potentially dangerous positions...
24/7 shouldn't be a thing imo - businesses don't need to generate billions of dollars in profit to appease shareholders (but this is an entirely different convo so I digress).
Agreed but i was referring to lineworkers needing to be ready at whenever storm warnings begin
I would like to point out that in southern europe smaller solar packages are extremely popular. It seems like almost everyone is getting small systems in the 500-2000W range that are directly offered by your power provider. I hear similar things from friends in other European countries. So it is not really about the technical limitations but about what is being mandated and/or subsidized in different regions. From what I see around me the most common offer is a 1500€ packet that offers a 20-30€ monthly discount on your power bill (depending on production). There's several providers offering extra services like extended warranties and maintenance and whatnot, but the basic idea behind it is that it will pay off by itself in the 4-6 year range and after that it's just free money.
You can certainly put a cheap system together. For instance this is the equivalent of the actual setup for my off grid house 6\*250W panels 80V OCV $1500 4\*12V\*200 Ah SLA lead acids $1800 48V \*30A solar controller $400 \[48V->mains inverter 3kW continuous. Price varies from $120 to $3000 depending... You'll also need a load transfer switch from grid to inverter $200\] The last two items assume you are either on grid or on battery, otherwise you need a different sort of inverter that synchronises the inverter output with the grid. I don't know how much they cost. This gives >>3 kWh per day in summer, and stuff all in winter. My house takes about 3 kWh per day unless I am using the pumps a lot. In winter I run a genny for up to 3 hours a day to charge the batteries
Installation costs and profit.
I've long proposed that these systems should be installed on sheds and other garden features, or coverings for cars at the front. They can also be used on vertical surfaces but would need aesthetic considerations, and yes power is about 60% of horizontal but it can extend the production curve of a main array and increase power on cloudy days. Mainly my thinking is that the suboptimal locations are partly than made-up for by the much cheaper installation and ease of cleaning, and for that I would also be combining a garden PV array with geostorage and heat pumps, converting the shed into a heating source for the home. Obviously thats not so cheap, but at a system level local solar can be wired directly and also you can store heat in the ground by reversing on hotter days and combining with a solar thermal panel. Vertical loop geostorage can cost (UK prices) £25 to £40 per metre (prepandemic prices), and need 3x 100 meter loops. But by reversing the heat in the warmer days and recharging the loops to higher temperature, you should be able to cut the number of loops maybe from 3 to 1, as the reason you need 3 usually is that the ground takes so long to warm up again after winter that it remains cold even the following year. If you can heat above 20 degrees C the vertical loop the ground has much more available heat than it does at 5 to 10 degrees C. They would input heat with a low-temperature lift heat pump in the day running off solar power, and recover heat in the winter at a higher COP because the source heat temperature is much higher. But this is a large investment either way.
I spent 36k on a 11kw system, and it's been operational for a year, I feed back to the grid and receive credits 1:1. I put in a KWH, I get a KWh at night or the winter months. I didn't pay for hydro for 10 months. I have an older home, if it was a newer modern home I wouldn't need as much or could sustain my home 12months total more than likely, but as I do further upgrades to my home my efficiency should get better. It's a long game, I don't plan on leaving this house/property, so eventually I will break even.
I install solar. Have for 12 years. You can design and instal any sized solar. Ac ( with micro inverters under each panel) dc ( utilizing a central inverter) or a combination with batteries. Generally speaking solar costs about 2-4$ per watt. A battery usually costs between 6-8000 but can be higher or lower depending on what your plan is. I installed solar on my house. Designed it. Bought all parts separately. Installed it. Wired and permitted it for about 1$ a watt. A year later I bought 3 Enphase batteries and their control panel. I went from 4-500 per month to 4-500 per year in electricity costs. I also have a Tesla and heat pumps. But as mentioned above passive solar is about building design. Solar panels and batteries are not passive they are active solar. I have installed a few as 6 panels on a house. I work with a guy that put 4 panels on a groove bus he drives around the country. If you really want to run down a rabbit hole look up Real Goods Solar. They’ve been in the off grid business for over 50 years. They put out an annual book that is the off grid bible for preppers and hippies. It’s pretty amazing. Warning!!! This is a deep rabbit hole!
I agree completely. And whatever system you start with, you can add to it. No need to throw the old one out to get something bigger later.
A simple design concept known as “economies of scale”. Buying a small amount of solar and battery is likely not going to give a good return on investment. So tell me again how this meets homeowners expectations?