CPS Energy will buy 200 megawatts of wind power near the Gulf Coast from Duke Energy Renewables for the next 25 years, the utility announced Monday.

The purchase will help move CPS toward its goal of 1,500 megawatts of renewable energy by 2020.

Duke Energy Renewables, a unit of Duke Energy based in Charlotte, N.C, plans to build and manage the wind farm about 20 miles from the Gulf of Mexico in Willacy County.

The agreement's timing, though coincidental, comes as high temperatures and high energy demand have stressed the state's power grid, which has received a much-needed boost from Gulf Coast-generated wind power.

In a conference call Monday, Trip Doggett, CEO of the Electric Reliability Council of Texas, which manages the grid, said wind energy generated from the coast played a significant role in offsetting some of the state's peak demand for power.

Doggett said that because Gulf Coast wind farms capture wind patterns that usually pick up toward the late afternoon, just when power demand starts to rise, coastal wind constituted about 70 percent of the roughly 2,000 megawatts of wind power generated last week.

A total of 1,216 megawatts of coastal wind power goes to the grid, Doggett said, adding that he hopes to see more wind farms developed along the coast, especially after seeing their recent performance.

Though most cities are still broiling, Doggett said ERCOT does not expect any power shortages or outages this week because temperatures are generally cooler statewide than a week ago. The high-pressure weather system over Dallas last week has shifted.

“It's amazing the difference 2 degrees will make,” Doggett said. But he warned that just because no power outages are expected, that doesn't mean some won't take place this month or that people shouldn't conserve, particularly between 3 and 7 p.m.

“I don't want to say we are out of the woods,” said Doggett, who added that ERCOT forecasts an additional two weeks of triple-digit heat.

Once the Duke wind project comes on line in December 2012, CPS will have 1,059 megawatts of wind energy capacity. CPS spokeswoman Lisa Lewis said that project plus a pending 400-megawatt solar farm could guarantee the utility meets its 2020 goal in the next couple of years.

The price for the Duke project was not released. It will generate enough power for about 56,000 households on average, CPS said.

The deal is the second energy purchase between CPS and Duke Energy Renewables, the first being the 14-megawatt Blue Wing Solar Project, which opened in November.

Most of the CPS' wind farms are in West Texas and the Panhandle. Duke's project will add to the 357 megawatts of wind energy CPS already gets near the coast. When the project goes online, CPS will receive more wind energy from the coast than from the west and the north, Lewis said.