Photovoltaic panels have dropped to about a buck a watt retail, but I don't know if that's a significant change to your ROI.
My family is using about 25kWh/day at this point (trying to get it down). If I were to spend $1000, it sounds like I could buy at least the panels to provide a max of 24kWh/day (assuming a steady energy draw, which we don't have, of course). Is that correct? What are the other costs involved? Installation, obviously. Fixed costs like meters and infrastructure to get the power into the house. What would those cost for a 1kW system?
Feel free to respond with, "read article X." I honestly have done very little research, since I've always just dismissed PV as a possibility here in NC. Plus, right now electricity costs me $0.11/kWh, but I don't know how long that'll last.
Part of the problem is that the sun only shines for about half the day (minus clouds & rain), and solar insolation drops off with the sine of the latitude.
We generate (and consume) roughly an annualized amount of 250 KWHr/month. (It's a round number.) We've installed 3350 watts of panels to do that.
You're consuming 25 KWHr/day or 750 KWHr/month. By our ratio, at our insolation for our latitude, you'd need about 10,000 watts of panels. If you're further north than I am (and just about everybody in the rest of the U.S. is) then you could easily be looking at 12KW-14KW. The local PV installers in your area have websites linked to PV calculators that will help you determine a more accurate number.
That's just the cost of the panels, too, not the microinverters (or 2-3 string inverters) or the racks or the mounts or the wiring or the conduit. Then there's the electrician's labor and the cost of the construction permit.
For every dollar you save on consumption, that's several dollars you won't have to spend on installation. It makes much more sense for you to start with an energy audit, insulation, heavy-duty windows, CFLs, and all the improvements that I remember MMM has blogged about. You'll probably find a way to reduce your air-conditioning & heating bills, too. Then start with solar water heating. When you reach your new average energy consumption, you'll probably only need 7-8 KW.
Better still, in the next year or two I suspect that PV will only get cheaper. The global manufacturers have ramped up production just as countries have started to cut back on subsidies and people have slowed their buying. It'll take another year or two to get through the overhang, and that gives you the time to make your house much more efficient.
BTW some parts of the country pay tiered rates for electricity. One Mainland friend is only installing enough PV to cover his most expensive tiers of electricity, which should also cover most of his utility inflation. That might work for you if your utility charges tiered rates.
