Xcel Energy Inc. said Thursday it plans to quadruple the size of Windsource â¿¿ a voluntary program that allows business and residential customers to support wind-based renewable energy â¿¿ and cut the programâ¿¿s prices by more than half. Xcel (NYSE: XEL) also said it plans to create a new program within Windsource to allow large business customers to buy a minimum of 120,000 kilowatt hours of Windsource power with a five-year commitment. The purchase could work as a hedge if the price of coal and natural gas used to generate electricity rises in the future, according to Xcel. Xcel filed its plan Thursday with the Colorado Public Utilities Commission; if approved, the new plan could be implemented in the first quarter of 2012, said Steve Mudd, manager of the Windsource program. Windsource allows customers to pay a premium, on top of their regular monthly utility bills, with the extra money supporting wind-sourced power generation. Customers in the program can buy 100-kilowatt-hour blocks of Windsource power to offset their regular electricity usage â¿¿ allowing the customer to say that a percentage, or all, of their power needs are met by renewable energy. About 830 Colorado businesses are signed up with Xcelâ¿¿s Windsource program, Mudd said. Currently, Windsource encompasses about 221,000 megawatt-hours of power; Xcel is proposing to grow it to 850,000 megawatt-hours of power, Mudd said. On prices, Xcelâ¿¿s current premium for Windsource is $2.16 per 100-kilowatt-hour block, Xcel is proposing to drop that to $1 per block. A typical household uses about 632 kilowatt hours of electricity a month, which costs about $67 per month. Buying seven blocks of Windsource power, enough to cover the monthly use, would add $7 to the electricity bill under the new program, according to Xcel.