By Jesse Berst

In fact, just last week DOE announced billions of new loan guarantees for a variety of solar projects. This just months after California solar panel maker Solyndra – which received $535 million in DOE loan guarantees – filed for bankruptcy and soon thereafter became the target of an FBI investigation.

That was, of course, great ammunition for critics of the Obama Administration's clean energy policies – and others who simply question whether these loans are getting the due diligence they should.

Over the weekend Energy Secretary Steven Chu was on the defensive. The Associated Press quoted Chu as saying the U.S. can't afford not to invest in clean energy. "It’s not enough for our country to invent clean energy technologies, we have to make them and use them, too," Chu said. "Invented in America, made in America and sold around the world. That’s how we’ll create good jobs and lead in the 21st century." And Walter Streight Howes, a former senior DOE official in the Clinton and Bush Administrations who helped develop the loan guarantee program, appeared on Platt's Energy Week program on Sunday and defended the DOE's handling of the Solyndra loan.

But now we're hearing about yet another DOE loan recipient, Nevada Geothermal Power, facing financial problems at its only operating plant. The New York Times quotes the start-up's own auditor as expressing "significant doubt about the company’s ability to continue as a going concern." The amount of money at risk is much less than Solyndra; a loan guarantee of $79 million and some $66 million in grants, according to the Times.

Jesse Berst is the founder and chief analyst of Smart Grid News.com. He consults to smart grid companies seeking market entry advice and M&A advisory. A frequent keynoter at industry events in the US and abroad, he also serves on the Advisory Council of Pacific Northwest National Laboratory's Energy & Environment directorate.