Is Wisconsin too eager to invest in ethanol?

According to the Platts energy information service, government will mandate the use of 7.5 billion gallons of ethanol for vehicle fuels by 2012.

But the growing number of U.S plants will meet that demand and more by the end of this year, raising fears of too much supply.

Wisconsin is a big part of the growth trend. The Badger State is the country's seventh-largest ethanol maker, with seven plants running and eight more under construction or planning.

About 20 percent of the Wisconsin corn crop is now dedicated to ethanol. Metal fabricators have turned away other jobs because they're too busy making steel for the new ethanol shops.

Taxpayers have a stake, too, because of the millions they've spent here and elsewhere on promotion and production incentives.

Gov. Jim Doyle says Wisconsin will be left behind if the state does not invest in renewable energy.

Investors are smiling, at least for now.

Those who spent $1,000 for a share of the Badger State Ethanol plant in Monroe in 2002 are now sitting on almost $7,000, with solid dividends each year.

But the head of American Capital Strategies says the cost of ethanol plants has grown rapidly and it's got at least some equity firms being more cautious about funding new facilities.