Wind power costs released

But the cost is a little more complicated than that, since it doesn’t include the benefits to ratepayers of “off-system sales,” or the power displaced by wind energy that CPS is able to sell into the market, Cris Eugster, the utility’s chief sustainability officer, told the CPS board of trustees at their meeting Monday.

It also doesn’t include the congestion costs CPS must pay on days when the amount of wind power produced exceeds the capacity of lines that can carry it to San Antonio.

“What you’re really doing is investing in a generation resource that will serve San Antonio over the long term,” Eugster said after the meeting, “and to avoid the costs of a new power plant.”

The average cost per kilowatt hour for the utility’s portfolio of renewables — 97 percent wind turbines, with a little solar and landfill gas — is 5.2 cents per kilowatt hour.

By comparison, nuclear power costs the utility less than a penny per kilowatt hour; coal costs 1-2 cents, Eugster said.

But to do an apples-to-apples comparison, he said, “all-in” costs for new generation should be compared.

When you include the cost of building a new coal plant, for example, the cost for a kilowatt hour of coal jumps to between 7 and 11 cents.

Eugster’s presentation on the cost of renewable power sources was a first for the utility, which in the past has been more circumspect about the specific costs, often citing competitive concerns.

While CPS owns most of its generation, in the form of nuclear, coal and natural gas plants, it buys wind energy and solar power for a set price and time, generally 20 to 30 years. CPS’ goal is to have 1,500 megawatts of renewable generation by 2020, or about 20 percent of capacity.

Renewables now make up about 13 percent of capacity, but only 11 percent of actual generation. Nuclear, by contrast, makes up just 15 percent of the utility’s total portfolio, but because of its low cost, 40 percent of actual generation.

Wind power prices have varied since CPS began buying it in 2002. Prices hit a low of 0.7 cent per kilowatt hour in 2005, and a high of 7.7 cents in 2008. That was in large part because of $61 million in congestion fees CPS was forced to pay to bring the wind farm to San Antonio.

Since then, Florida Power & Light has built a transmission line that greatly eased congestion; costs were reduced to $13 million last year.

By Tracy Idell Hamilton,