Brother in the UK:
28 panels 460W = 12.88kW
13.5kWh Tesla battery (half of the cost)
Cash price $20k
Very nice-looking installation. Battery control decides to charge from mains supply based on night tariffs and weather forecast.
USA quote:
35 panels 405W = 14.175kW
Microinverter - per panel - Enphase. SEG panels.
No battery
Cash price $56958 - $17087 Federal Tax credit = $40k cash
Twice the price for a worse performing system.
I would have gotten more quotes, but since we would need a new roof first, we decided not to do it.
Anyone else done it [installed solar panels]? Cost/specs?
Yes, the UK not great for solar, and I don’t know if the system would be economic without the battery and ability to charge it from the mains supply at off-peak rates.
I certainly didn’t compare to other countries. We installed solar maybe 15 years ago (give or take). We kept it within the subsidy limits (5kW). We got a rebate from SRP, a tax credit, and generating ~$100 per month, it paid for itself in 6 years.
Arizona is a prime solar market, with about 300 days of sunshine a year. Efficiency goes down as the panels get hot. But, usually, we have 1-2 months per year where we generate more than we use (usually March/April). So we only pay various fees that everyone pays. In May we use up that credit (reliably).
Such a large installation for us would not make sense. Sure, we’d probably generate enough for us year-round. But SRP only carries the credits for a year. If you don’t use them, you lose them. In the cooler times of the year, we wouldn’t even come close to using the 13kW. So we’d be building credits that would never be used, and SRP gets free power from us.
We probably could have installed a bit bigger, but the ~$100 per month savings seems to be perfect. At this point, the system is printing money for us. PLUS…SRP did two different studies that included our system, and in one of them we got a free state-of-the-art inverter (operates much more quietly, much more efficiently, and throws out less heat in the garage).
Note: ours is grid-tie. The economics of a battery setup would be a bit different (e.g. SRP wouldn’t have given a rebate for a battery system).
Interesting. The 35 panels/14kW system I was quoted was to cover our average electricity usage. Panels on both sides of the roof. I think a smaller system using just one side might be more cost-effective.
It’s moot for this particular house - I’ve just discovered that our Home Association will not allow panels on the front of the house. Putting them on the back only would be pointless.
I’m trying to convince Mrs.C. that we should build a new house, a ranch, pointing the right way with solar from the start, closer to amenities, and most importantly, close to the bike trail. No progress so far…
There are many factors. One is where you live. If you don’t get much sunshine, maybe it isn’t worthwhile to install solar. I would have to look up the federal tax credit (if any), and you would have to check the state you plan to build. And then you would also have to check the utility in that area. The states and utilities can all be different.
Utility handling of excess production can also vary, and may dictate the size of the array. Building to your average consumption may or may not be wise depending on how that is handled, plus any size-based rebates (e.g. SRP limited us to 5kW, with no additional benefit to building larger), etc. It’s all very dependent on where you plan to build.
But, if it makes sense in those terms, then having a southern-facing roof slope somewhere for mounting the panels is a good idea.
I check into the costs of installing solar panels every 6 to 12 months. So far it never pencils out as economical. And not by a little (if it were just a little, I would do it), but by quite a lot. Breakeven comes out decades in the future, and I’ll probably be dead by then, or certainly not living in this house anymore.
That’s weird. My brother did it (Massachusetts) 6 years ago (maybe 8, I forget)and he’s already broken even, has a $3,000 credit with his utility, and is thinking of putting up even more on his garage for the day he gets an EV. Of course Massachusetts government is very solar friendly, not all of them are.
My problem is I have a wood roof (cedar shake) so I’m not allowed panels on it. I’ve flown about 2400w off the deck and have another 1000 on the ground; it’s enough to charge the EV and occasionally dump to the hot water heater. No grid interconnect, my utility has made that a hard game to play.
My solar, with Powerwalls, was installed just over two years ago. I was offered 1% financing, and took it. I also have net metering, so I get credit for what I send to the grid at the same rate I would be paying. That rate, currently $0.31452 per kWh, is on the high side, but that just means I get a higher credit. Anyway, what I save from not buying, and am paid for selling, covers the payments on the loan.
My problem is I have a wood roof (cedar shake) so I’m not allowed panels on it.
Is that a code requirement? We have concrete tiles, and when they installed our solar, they just cut notches in the tiles for the mount supports, and drilled holes into the roof deck to secure the mounts, and then did whatever magic they did to make sure the holes in the felt were sealed. Which is why I say that one should have solar installed by a licensed roofing company that also does solar. They’re going to have to punch holes, so they better be experts and sealing them. Some solar companies aren’t roofers, and you don’t necessarily know whom they will summon to patch the holes (or maybe they’ll do it themselves, even though not licensed).
The pay-back time is highly dependent on your climate, and your local regulations and incentives. Ours paid back in about 6 years (in Phoenix). I’m surprised to see an estimate of decades for pay-back, but without knowing the specifics, I can’t say it isn’t so. It very well may be given expected generation and limited incentives.
To be honest I’m not sure, but have read it’s a common local regulation/code. When we first moved to this house about 6 years ago I got quotes from 3 installers, except oops, none would install because of the “wood roof.” As I got to thinking about it I saw the wisdom of that and didn’t inquire further.
Tennessee (where I live) is pretty loosey goosey with code, but a neighbor (UT Professor in alternate energies) said “he wouldn’t be surprised.” He’s in the adjacent neighborhood and has had a full rooftop set for 20 years, maybe more.
Anyway, it wasn’t the “drilling holes in the roof” that bothered me; I did more than a dozen to put up a backer board to have 4 awnings installed, it was the “fire” part - especially after I overconnected a couple of panels and had the cable go hot within a minute or two. (Safely fixed without incident, but as they say “A learning experience.”)
My brother got payback in just a few years (either 6 or 8, I forget), but that’s Massachusetts. At the time Federal incentives, state incentives, and (again at the time) net metering back at the retail rate. My neighbor here in TN had that same deal very early, but the local utility stopped that quick. Still, he paid back in about 12, IIRC.
My electric bill is under $100 in winter (3 mo), $150-180 spring/fall (5-6 mo), and $250 in summer (3-4 mo). Let’s call it $2300 a year. It’s been pretty steady at those numbers more or less for quite a while. So 10 years of total electric bills come to $23,000 or so. A solar system will cost me way more than that, probably even more than twice that amount. And if I add batteries, probably more than 3 times that amount. That comes to 2 decades or 3 decades of total electric bills. Now add time value of money, and it’s even worse. And add the $35.xx a month I would have to pay the power company anyway and it’s even worse. It just doesn’t hit breakeven for a very long time. My house is all electric, and I’m pretty sure I am not eligible for any credits. If I ever have a low income year, I will of course run the numbers again as I do every year. Because I really want solar!
I know people who find ways to fool themselves that it is hitting breakeven, but I suspect that they are aren’t using real numbers or they pay a lot more for their electricity (this is why the numbers worked out extremely well in CA when they still allowed credits plus negative metering) or they are comparing two different things. Like comparing the “monthly” finance payment versus their electric bill. When they have to relocate 6 years later due to a job change, they get a HUGE surprise at closing; they have to pay the ENTIRE next 14 years balance plus perhaps a penalty clause of some sort. That’s gets directly subtracted on the HUD-1 form, it is literally cash out of your pocket.
We worked out that we were saving an average of $100 per month (more in summer, less in winter). Given the cost of our system, plus utility rebate, plus tax credits, it was pretty simple math to calculate the pay-back time was about 6 years.
Ours is grid-tie, so no batteries (in fact, batteries would have made us ineligible for the utility rebate). Batteries would have extended the time to break-even (this was before Powerwall, so it would have been a bank of -probably- marine batteries).
Wow! A random AI says present value of $100 a month for 6 years is $6222.50. How did you find a system with installation minus tax credits and rebates for only $6200??!!!?? Any system here is at least $20k for the most bare bones system possible (no batteries, nothing fancy, maybe 8kW or so).
It was about 15 years ago. The cost for 5kW (the max the utility would rebate) was something around $25K. I don’t remember the rebate now, but it was sizeable. And then the tax credit did the rest. So our out-of-pocket was between $6K-7K.
I wanted to install more, but it would have been entirely out of pocket for any additional, and that pushed the break-even point ahead many years. So we stuck with the 5kW, which -as I said- is saving us about $100 per month, average.
EDIT: It would have been over $7K out of pocket. I thought about it later, and $100 per month for 6 years is $7200. Not sure what your AI was doing. And our break-even was a bit over 6 years (maybe 6.5?). So it would be more accurate to say our out-of-pocket was between $7K-8K. But the system has long since paid for itself, and now just prints money.
