Buried in a regulatory reform bill proposed by Gov. Scott Walker earlier this week lies a provision that wind energy insiders say could shut down 12 wind farm projects, cost investors billions and essentially kill the industry in the state.

In the bill announced Tuesday, Walker seeks to quadruple the distance between wind turbines and neighboring property.

The governor said the provision was written to protect homeowners, many of whom have complained about the encroachment of wind turbines in the rural parts of the state. Opponents of wind farms have complained of diminished property values, occasional noise pollution, moving shadows cast by the giant machines and loss of sleep from vibrations.

But critics this week called the provision a job killer and said it would earn Wisconsin a reputation for being hostile to alternative energy sources, such as wind.

"It would in essence shut down wind energy in the state," said Denise Bode, CEO of the American Wind Energy Association. "It is one of the most onerous regulations we have seen."

Bode said that, if passed, the measure would shut down 12 wind farm projects worth about $1.8 billion. Those projects, which are in various stages of planning, could produce about 950 full-time jobs for one year, she said.