Solar panels on the roof?

December 14, 2010 7:31 PM

I want to install solar panels when I replace my roof next summer. What do I need to know about manufacturers, incentives, and costs? I am in Washington state.

I live in a suburb of Seattle and, don't laugh, I believe my roof is an excellent candidate for solar panels. It's got a relatively shallow slope and is currently a torch-down roof that will need replacing next summer. While we're replacing the roof, it would be nice to put a solar system up there.

In Washington state the local utilities are required to buy energy back from homeowners and a certain rate. This rate increases if the system components are manufactured in-state. I believe there is a federal tax credit as well.

This web page has a pretty good breakdown of how to calculate cost-effectiveness but I am hoping to get more details and some personal experiences.

1) Have you installed a solar system in your home? What was the process like? Are you glad you did it? Are the finances working out as you expected?

2) Is the information on the link above correct and up to date?

3) Are there in fact components manufactured in WA that I can buy in order to get the increased buyback rate? Do these manufacturers have a good reputation?

4) How can I really decide if my roof is a good candidate for this?

5) What goes into claiming the various tax credits, etc?

6) Is there anything I'm not taking into account or should consider?

posted by bq to home & garden (10 answers total)

I have a friend -- also in a suburb of Seattle -- who has a business answering these very questions. I believe his company can come to your house and do an audit to let you know just what would be involved in installing solar panels. To avoid sounding too spammy I'm not going to mention their company here, but please drop me a line if you'd like to be put in touch with them.

I have other friends in Everett who've installed solar panels and seem very happy with them; they brag about them on Facebook, showing charts of how much energy they're receiving.
posted by The corpse in the library at 7:46 PM on December 14, 2010

If you are looking to install passive solar panels specifically for the purpose of living off the grid/selling power back, you will not be able to accomplish this without a massive amount of cells. My suggestion is to find a company in seattle and have them come out and give you a quote.

I will say that I had them installed on my house (this was in NC) and they, along with other big upgrades, reduced my energy bills tremendously.
posted by TheBones at 7:49 PM on December 14, 2010

In general, solar collectors for hot water are more efficient (in terms of cost savings and likely in terms of environmental footprint reduction) than solar PV. Evacuated tube solar collectors are many times more efficient than PV panels. You can size a system to provide all your domestic hot water needs in the summer and part of your needs during the rest of the year.

You will pay back the cost of a solar hot water system much sooner than a PV system. On the environmental side, if you currently heat your hot water with electricity, you will reduce your electrical consumption significantly (more than you would with a comparable PV system), while if you currently heat with gas, you will reduce your gas consumption (the overall effect would depend on what the marginal electrical production in your area is (which I think is sometimes hydro and sometimes gas)).

If you install a solar hot water system that meets your needs and you still want to do more, then you can look at solar PV.

Talk to an installer in your area and see what they suggest for solar hot water. Either way you do this, it will cost you thousands of dollars.
posted by ssg at 7:59 PM on December 14, 2010 [2 favorites]

So, this may sound weird, but I'm just putting it out there: In California, business can get awesome tax exemptions if they own buildings with that generate solar power. The thing is, the buildings themselves don't actually have to be in California in order for the business themselves to get a tax break. When I was living in Ohio, the owner of building next door to me worked out some kind of deal where a company from CA technically bought the building, but the previous owners had a 99-or-so-year lease on it at a very low rent, and got the company to pay for putting solar panels on the roof.

I don't know if giving up legal ownership of my home would be worth it to me, but I'm not you.
posted by Jon_Evil at 8:06 PM on December 14, 2010

I'm memailing you the contact info for the folks who did our solar water heat a few years back. They can answer question 2-6. As for #1, it's Seattle. If you're installing solar PV here, you should probably be doing it for reasons which aren't purely financial. Unless things have changed in the last couple of years, I don't think the numbers work out well for single family residences. For solar water heat, I think they work out a little better. I haven't been keeping good records recently, but the last time I did a quick guesstimate, it looked like our solar water array was going to pay for itself before its warranty expired.
posted by hades at 10:50 PM on December 14, 2010

Your rook is a good candidate if it faces South.
If it face SSE or SSW, it can still work - but any other direction, and your roof is not a good candidate.
posted by Flood at 5:08 AM on December 15, 2010

I just had a 5.5 kW PV solar array installed on my roof in MA. That's more power than we use. Total cost was $44K. The payback is estimated at 7 years, but would be longer in a state that doesn't have the generous $10.5K rebate and 10% tax deduction that MA gives. MA has also instituted a system called SREC, where power companies must buy a percentage of their electricity from renewable sources (like my roof). Supposedly, I will periodically get a check for the power my roof makes, even if I use all that power myself. I don't know if WA has such a scheme in place. The Federal tax deduction is 30%.

In a 24-hour period in early December, if the daylight portion is mostly sunny, my net consumption is zero. On cloudy days, it's probably half what it would be without the solar panels. My roof faces almost due south, there are no trees or buildings shading it, and there's a lake across the street (which is supposed to help some).
posted by Kirth Gerson at 8:12 AM on December 15, 2010

Thanks so much for all the feedback! And yes, please email me any names of companies that could help us out.

And luckily for us, our roof DOES face almost directly south.
posted by bq at 1:22 PM on December 15, 2010

Oh, one more thing about my roof - it's pretty shallow, particularly for New England. That's a small disadvantage, most notably in the winter. The two companies I got estimates from both said it only cut efficiency by a few percent.

I only got two estimates because none of my emails to other installation companies were answered. I do not think either of the two work on the West Coast, but they were New England Breeze and Sunlight Solar. I went with Sunlight Solar, because they use more efficient panels. NE Breeze could not fit a 5kW system on the roof.

Wait - Sunlight apparently does install in WA.

I am generally satisfied with their performance, although they didn't start the installation until the loan window* was about to expire, which was a couple of months after they originally estimated they'd start. Then, the "five day" installation seemed to take about twice that. Power was only shut off for a couple of hours, though, so it wasn't a big deal. The power company had to approve the installation before I could switch it on, and that took several days.

* SunPower, the manufacturer of the solar panels has a "Same as Cash" program that pays the installer the total cost, as a loan to the customer which is interest-free for a year. The approval of the loan was only good for three months, and if the installers had delayed another week, we and they would have had to get approved again. I see that some installers in the Seattle area offer that loan.
posted by Kirth Gerson at 3:09 PM on December 15, 2010

Take a look at the Solar City web page. They provide a lease option that can give you a lower monthly energy bill with no money up front. They website allows you to enter the details for your own address to get a personalized estimate of what you can save.

I have a 4kW Sunpower system on my roof in Silicon Valley. Net for the year, I pay nothing for electricity, though I actually use a little more than I generate. However, I generate (and sell) much more during the expensive peak periods than off-peak so the final bill is $0. The system cost about $38K 4 years ago, I paid $28K after all the rebates, but prices (and rebates) are dropping fast so I have no idea what the economics look like now.

I'm not convinced that solar thermal systems are a slam dunk compared to solar PV. Yes, they absorb far more of the suns energy than solar PV (70% vs 20%) and they're a lot cheaper but, it comes down to how you heat your water, if you displace electrical water heating then it should make sense, but if you heat with gas, probably not so much.
posted by Long Way To Go at 6:48 PM on December 15, 2010 [1 favorite]