The chamber organization's news release stressed that "allowing the PTC to expire at the end of 2012 would hurt local economies, send jobs and capital elsewhere and risk ceding America's clean energy leadership to our global competitors."

As anyone who has been following the PTC issue and the presidential campaigns knows, the tax credit at the very least faces an uncertain future. Republican presidential candidate Mitt Romney and his running mate Paul Ryan have both pledged to get rid of the tax credit if they get the chance. President Obama supports it.

The uncertainty is already putting a major damper on the U.S. wind industry. Siemens, a giant in the industry, announced Tuesday that it's laying off 615 employees in its U.S wind power operations located in Iowa, Kansas and Florida. Siemens cited "federal policy uncertainties," competition from natural gas and slow growth in electricity demand.

Siemens said that it remains committed to the U.S. wind market and to keeping manufacturing plants. The company hopes to increase its export business to Canada, Latin America and the Caribbean to help it use its manufacturing capacity in the U.S. Other companies, including Acciona, Gamesa and Vestas have been following the same strategy as their plants put on the brakes.

The group of 19 companies plan to put pressure on lawmakers in the weeks to come. As their letter says, "Extending the PTC lowers prices for all consumers, keeps America competitive in a global marketplace and creates homegrown American jobs."

In addition to the companies mentioned above, the group includes Akamai Technologies, Annie's Inc., Aspen Skiing Company, Ben & Jerry's, Clif Bar, Jones Lang LaSalle, New Belgium Brewing, The North Face, Pitney Bowes, Portland Trailblazers, Seventh Generation, Sprint, Stonyfield Farm, Symantec, Timberland and Yahoo!, according to a Sustainable Business article.

And while Romney's position on the tax credit has rallied Republican opposition in Congress, not all Republicans are against wind. Kansas Gov. Sam Brownback, responding to the Siemens layoff announcement, said "I have been and will remain a strong advocate for the wind industry. While the federal government struggles with its effort to create a balanced energy policy, my administration will do everything we can to support the industry at the state level moving forward – and to assist those Kansans affected by this announcement."

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