Building all those windmills will be a major construction project, creating up to 14,000 new jobs and close to $2 billion in new investments, according to a study released this week by the labor-backed Apollo Alliance.

But to realize that vision, state lawmakers need to beef up minimum requirements for renewable resource development, advocates say.

To that end, Wisconsin lawmakers will soon consider a bill requiring at least 10 percent of the state's power to come from clean, renewable fuels by 2015.

If it becomes law (and a broad spectrum of industry and watchdogs are lined up in support), the state's power companies would have to more than double their current reliance on renewable fuels.

Economic sense Today, about 4 percent of Wisconsin's power comes from sources other than fossil fuels and nuclear plants - a figure that already surpassed the state's original goal of 2.2 percent by 2011.

Wisconsin was one of the first states to impose a minimum in 1999, and today is among 21 other states and Washington, D.C., to have a goal on the books.

Making it more demanding is an important step, according to state Sen. Robert Cowles, R- Green Bay, who said the $2 billion in wind development is too much to pass up.

"We can decide: Do you want to put roughly the same amount of money into coal and natural-gas plants, or conservation and renewables?" Cowles said. "We can change that equation."

But Wisconsin's proposed 10 percent target by 2015 is modest compared to many states. California, for example, has required 20 percent by 2017; New York is at 25 percent by 2013.

The joint industry- environmentalist task force that proposed the 10 percent level in a 2005 report sought to compromise on an "achievable" goal, said Dan Schoof, a staff member at the state Public Service Commission, who served in the group.

"It was a consensus," he said. "Many people would like a higher number . . . and some would say you shouldn't have any sort of mandate."

Comparing potential Some regions of the country are better suited to renewable resources - states with swift- flowing rivers, like Maine, have robust hydroelectric industries. Western states can make better use of the wind, too, Cowles said.

Because it is the most commercially viable, wind- generated power will almost certainly make up the majority of new clean-fuel projects for the foreseeable future, experts said.

Wisconsin ranks 18th nationally in its potential wind capacity, according to the American Wind Energy Association. That's higher than most, but 20 times less than the potential of leaders North Dakota and Texas.

Next-door neighbor Minnesota has set its minimum at the same standard of 10 percent by 2015.

"When you weigh all of those factors, a 10 percent by 2015 is a good target," said Dan Ebert, chairman of the PSC. "It is an aggressive target, but I think it's manageable."

Realistic target At Madison Gas and Electric Co., complying with the proposal would force the utility to quintuple its reliance on renewables, which currently stands at about 2 percent.

But it's a realistic target, said Greg Bollom, assistant vice president of energy planning.

"Getting there is not technically challenging," Bollom said. "It's not without its consequences, but it isn't so much the technical feasibility as it is the economic impacts."

Alliant Energy's local subsidiary, Wisconsin Power & Light, has the capability to produce just less than 7 percent of its power through renewables.

Today, wind power can cost up to three times more than typical coal-generated power.

But technological improvements and the long-term benefits of using free, unlimited wind - instead of expensive, ever-diminishing fossil fuels - means that building new wind farms isn't any more expensive than conventional plants, said Charlie Higley, executive director of the Citizens Utility Board.

As a precaution against excessive costs, the bill includes provisions that allow a utility provider like MGE or Alliant Energy to get a temporary extension on the 2015 deadline if the PSC determines it would harm ratepayers.

State Sen. Mark Miller, D- Monona, authored a different bill in 2005 that would have required a 15 percent minimum. He will support the current proposal but still thinks the state can do better.

"It reflects the political realities in this state," Miller said. "But my hope is that if we adopt a 10 percent standard, we will recognize in very short order that it needs to be higher."

The push for mandatory standards is spreading as industry-friendly conservatives latch on to the benefits of new technological developments, said Jennifer DeCesaro, an energy expert for the Denver- based National Conference of State Legislatures.

"It's becoming less of a partisan issue than it might have been five years ago," DeCesaro said. "It speaks to everyone, because it does have positive impacts on economic development."