You may be wondering how long it takes to spend $17,600. Vicky got the ball rolling back in February. She came up with two contractors with experience. One didn’t return our calls, but the other one produced really good vibes. I wrote about him in the Megatrends issue of Electronic Design in June. He’s the guy with the all-electric RAV4 (see “Alternative Fuels Look To Solve Petrol’s Plunder,” ED Online 12857).
The roof job happened in March. It was fast and painless, except for writing the check. What made the rest of the system installation last until the end of July was panel availability. As I remarked in an e-mail to an ED reader, I don’t recommend solar panels as a recipe for instant gratification.
The problem seems to be that while European demand for panels (lots of subsidies) is still very strong, demand in the U.S. is ratcheting higher, and supply isn’t keeping up. When we started this exercise last winter, the contractor bid certain Kyocera panels. Then it appeared that they couldn’t be obtained with love or money, and he found some Sanyos he though he could get his hands on.
The Sanyos would have boosted our cost by a couple thousand dollars. But they used three-layer cells, with different bandgap energies at each layer, so the output would have been higher over a wider range of sun angles. The source for those dried up, though. The contractor then found some other Kyoceras that will cost less than the original bid, but they’re a little less efficient—at least nominally. As I said, they seem to be quite a bit better than they’re rated.
Fairly soon after we got the new roof, the solar contractor installed the inverter and ran conduit between it and the roof and between the inverter and an emergency cutoff down by the service entrance. And then we waited, while the contractor gave us periodic updates.
Finally, the contractor scored the panels—at exactly the time that local midday temperatures soared to new records well beyond 100°F. But once the panels were in hand, even just working early mornings, everything was in and wired up. The county inspector signed off on them by the early afternoon of the third day.
Now we’ll just have to wait and see. If I have any interesting tidbits to add, I’ll post them here.
UPDATE: In the system’s first week of long, sunny summer days, it put 124 kWh on the grid. In my initial writeup, I also left out an expense: $277 to the utility for a new electric meter that can handle different rates at different times of day. It hasn’t been installed yet, and we’re still on the standard flat-rate billing plan.
SECOND UPDATE: It's a week later. The guy from the utility is coming later today to install the smart electric meter.
THIRD UPDATE: About 20 minutes after this story was posted on-line, I received an email from a reader at Sandia. He directed me to a Web page (www.fsec.ucf.edu/EPact-05.htm) that describes The Energy Policy Act of 2005 (EPAct 2005). In brief, the act says we're eligible for a $2000 tax credit. As Mr Campbell notes in his email, that shortens our payback time by about a year and a half!
And the smart meter is now installed. It looks like a conventional meter, except that a multi-function LCD display replaces the old clockwise/counterclockwise dials. Amusingly, the display also includes an LCD analog of the old rotating silver disc—a series of marching dots and a pair of arrowheads that indicate which way an actual disc would be spinning. The man who installed the meter also told Vicky that we would now be billed for electricity only once every six months.
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