[This post is part of a series about our net-zero residential solar project – to see a list of links to the full Solar Project series, click here or to bring up a list of all green-themed posts, click here.]
I have been getting enough questions from the blog readers and neighbors that it is time to do a frequently asked questions list. I have divided the common questions into four groups: practical questions, financial questions, technology questions, project questions and philosophical questions. These are the basic Practical Questions.
Practical Questions
Q: What about the shingles on your roof? What if they wear out before the life span of the panels?
A: One of the more common questions. In our case it is moot – we have a standing seam aluminum “100 year” roof, so we don’t have those concerns. But with an older asphalt roof you certainly would. Most people with older roofs choose to re-shingle at least the south side before putting up the racking. People with newer roofs can make the calculation – will the diminished weather and sunlight the roof will see when covered with panels mean it lasts long enough to span the life of the system? With good shingles that are not too old, you would probably be ok – the life span would be increased enormously by being sheltered by the panels. The exposed edges might be more of an issue, but they are easier to fix, or even patch with a little tar if you really had to. Also worth keeping in mind: if you are financing equipment, you may be able to bundle the cost of roof repairs into that deal – such an option is commonly offered by the “turn-key” solar installers. Doing so may enable you to take a tax credit for roof work you would otherwise have to undertake down the road anyway. (return to list of questions)
Q: Will it work on cloudy days?
Yes, because solar panels absorb various spectrums of visible and invisible light, but the energy produced by the system will be less than when the sky is clear and sunny. How much less depends on the thickness of the cloud cover. (return to list of questions)
Q: Will it work on snowy days?
If it snows enough for there to be a significant accumulation sticking to your panels, they obviously will not produce electricity. However, snow slides easily off of the glass panels, they tend to be located where your roof gets the most sun and they are dark colored so they heat up in sunlight which means the snow on your panels will melt first, and your panels will resume producing electricity pretty quickly after a storm. If you live in an area that gets snow in the winter as we do, your installer will factor in snow days when calculating your system’s projected production. (return to list of questions)
Q: Do they work just as well when it is really cold?
Yes. Solar systems work in all climates, and often work better in cold temperatures during winter months because cold temperatures cause an increase in the conductivity of metals and wires. On the converse, extremely hot desert conditions can cause a slight reduction in the efficiency of panels. (return to list of questions)
Q: What about other extreme weather?
Solar panels can handle some pretty rough weather. Solar houses have made it through recent hurricanes (including Irene) with minimal damage. Most solar panels are guaranteed to withstand 3/4 inch hail balls at 120 miles per hour, and they are also built to withstand direct lightning strikes. Of course if nature does damage your panels, your installer and manufacturer should fix them for free. (return to list of questions)
Q: How long does it take?
Four to eight weeks is a good estimate. The planning process can be as fast or slow as you want it to be. We took a few weeks and a few visits from the installer to get organized. Once you have a plan, you need to do some paperwork and apply for rebates, etc. This only takes an hour or so of your time, but approval of your rebate application can take a few weeks to come through. Then you need to schedule and start your installation. Installation of even a big system can take anywhere from a couple days to a week, but you need electrical inspections and utility inspections along the way, which can introduce delays. Given the complexity of these projects, they happen remarkably fast, but just don’t expect it to come together overnight. (return to list of questions)
Q: What if I cannot fit it on my roof? Can I still do it?
In certain situations, a non-roof installation, such as a ground-mount system, a patio shade system, or a trellis or gazebo system can be designed, zoning rules permitting. This is something you can discuss with your installer. (return to list of questions)
Q: How long will the system last?
Most residential solar power systems are predicted to last up to 35 years. SunPower has some systems which were installed in 1975 that are still outputting over 80% of their rated power. The SunPower panels we are using have a 25-year power output warranty, which they claim is the best in the industry, plus they have a 10-year warranty on the panels and workmanship. They also offer inverter warranties of up to 10 years. For a discussion of this in the context of 20 year leases, see The Solar Project – This Might Actually Be Possible (Federal & Macroeconomic). (return to list of questions)
Q: What kind of maintenance is needed for a residential solar power system?
Most residential solar power systems are fairly simple and have no moving parts. They don’t typically have mechanical problems. Inverters tend to need replacement at around ten years. Except in very dry dusty climates, or in flat installations, panels do not require regular cleaning. Seasonal rainfall is usually enough to keep the panels operating at peak efficiency. If they need a rinse, a garden hose will generally do the job and if they need a scrub, a soapy brush on a long handle will suffice. (return to list of questions)
Q: Do I need to apply for permits to install solar?
Yes, but your installer will handle all the permitting issues related to your project. And a good installer will also handle all the related paperwork around selling your SRECs and dealing with your utility. (return to list of questions)
Q: What if a squirrel or some other animal moves in under the panels?
Independent Power Systems installs a very tough-looking wire mesh “squirrel guard” all the way around the perimeter of your array. Not every installer bothers, which means unprotected arrays can have wires chewed and other issues crop up. (return to list of questions)
[This post is part of a series about our net-zero residential solar project – to see a list of links to the full Solar Project series, click here or to bring up a list of all green-themed posts, click here.]
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