You need to have some kind of alternative energy thing going if you're using up electricity at a rate five times the average of your neighbors and you want to claim that you're living a green lifestyle.

A Woodside homeowner who prefers anonymity and who pays about $40,000 yearly for 105,000 kilowatt hours (kWh) of electricity is having a 10-500-square foot ground-mounted solar array installed on a secluded meadow to cover all his electricity needs, says Dave Markham, the owner of CM Peletz Co., a high-end-home contractor with offices in San Jose and San Francisco.

The average Woodside home uses 17,544 kWh in a year, says Pacific Gas & Electric spokeswoman Katie Romans. Comparable figures for Atherton, Portola Valley and Menlo Park are 20,064, 12,360 and 5,976 kWh, respectively. The San Mateo County average is 5,784 kWh.

The project will cost about $850,000, but government incentives cut that by about 42 percent. It will pay for itself in eight years, Mr. Markham says. With a 25-year warranty on the silicon-based solar panels, that works out to 17 years of free electricity.

The solar array was a feasible alternative to fixing energy leaks in the house, which would have required replacement of classic details such as the windows. "It would have cost a fortune," Mr. Markham says.

When the solar panels gather dust, the output will drop predictably, a signal to have workers squeegee the panels clean, he says.

PG&E does not pay for excess solar power that feeds into its grid, and the CPUC requires PG&E to wait until the end of the year to charge when owners draw from the grid. If a home system regularly generates more electricity than needed, residents have the opportunity to switch an appliance from gas to electric to take advantage of it. If it generates less, they have time to cut their usage to within their system's capacity.

Incentives helped

As of Jan. 1, 2009, the federal government removed a cap from the federal Solar Initiative Tax Credits: until 2016, an investment of $1 million yields a tax credit of $300,000, Mr. Markham says.

(A tax credit subtracts a specific amount from taxes owed; a deduction has a lesser effect in that it lowers taxable income.)

The performance-based incentive of the California Solar Initiative Program reimburses solar-panel owners per kilowatt hour for the first five years of operation. In PG&E territory, the current rate is 22 cents per kWh for a residential project -- a locked-in return of $115,500, Mr. Markham says.

The incentives drop over time, CPUC analyst Melicia Charles said in an e-mail, adding that the 22-cent incentive is "approaching" a decline to 15 cents.

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