DEBRIS.COMgood for a laugh, or possibly an aneurysm

So, PG&E is bankrupt, rolling blackouts are imminent, and energy rates are rising faster than Gray Davis’ bile. What’s a technology junkie to do?

I’ve been researching residential solar power systems. California pays a sizeable subsidy — $3 per generated watt, it turns out, or 50% of the cost of the entire system, whichever is less. Which raises the question: exactly how much would a residential solar system cost?

The first step toward an estimate is to size the demand. Dig out the last year’s worth of electricity bills and add up the monthly Kwh figures. Divide by 12 to find your average monthly usage (and cringe, if you tend to leave lights on or use an electric oven).

I found cost estimates in two places: Six Rivers Solar and SolarDepot.com, with additional figures from Occidenal Power. The concensus is that every kilowatt of generation capacity costs ~$10,000, post-subsidy, and provides ~150 Kwh per month.

Electricity in California, pre-bankruptcy, cost about 11 cents per kilowatt-hour, so over a 20-year period, a 2 kilowatt system would save me (20 yrs * 12 mos/yr * 300 KWh/month * $0.11) about $8000. Given an installation cost of ~$20000 that seems like a very bad investment. Even with a 100% rate increase from PG&E, a $20k PV solar investment would take 25 years to pay off. Can that be right?

I hope these calculations are incorrect… I’d love to take advantage of the state subsidy, and stop relying on PG&E’s shoddy service. But if these figures are accurate, I don’t have any choice but to wait for photovoltaic prices to drop significantly.

The California Energy Commission has a nice site on their subsidy, called the Emerging Renewables Buy-Down Program, but it would benefit from a simple worksheet to assist with system sizing and cost estimating.

In the meantime, I guess all I can do is conserve.

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Update: The above numbers are incorrect; the costs are lower, and the rebates greater than described here. For example, as of 2004-2006, a 2.5kW PV system costs $15-$18k and takes 12-14 years to pay itself off. We have since purchased a solar power system.

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posted to channel: Solar Blog
updated: 2006-02-25 17:32:48