From an article by Kevin Murphy in the La Crosse Tribune:

MADISON — Xcel Energy customers could choose to have more of the electricity they use come from renewable sources if the Wisconsin Public Service Commission approves a request Xcel submitted Friday.

The Voluntary Renewable Energy Source program would allow Xcel to charge $1.15 per 100 kilowatts for power produced by wind, solar or biomass sources but not from hydro, said David Donovan, Xcel’s manager of regulatory policy.
For typical residential customers using 750 kilowatts of power a month, the “green pricing” premium would add $8.62 to their existing $81.57 bill.

Xcel is the last utility in the state to offer an optional green energy plan for customers, Donovan said, but the company generates 14 percent of its power from renewable sources and has added 1,200 megawatts of wind power in recent years.

“Now there is a demand for it. Not just from residential customers, but commercial and industrial customers are interested in renewables beyond our base rate,” he said.