When the solar manufacturing company Solyndra went bankrupt last September after receiving a $527 million loan guarantee, it sparked a politically motivated congressional investigation into the White House’s handling of the program — an “investigation” that critics admitted would “stop on election day.”

After acquiring 300,000 documents, holding a dozen hearings and official meetings, issuing two subpoenas, and spending more than a million dollars on the investigation, members of Congress failed to present any evidence of political wrongdoing.

Congressional critics have “not shown the loan was granted as a result of political favoritism, despite repeated campaign-trail claims,” reported The Hill.

That didn’t stop special interest groups from spending millions of dollars on television ads this campaign season to trump up the Solyndra bankruptcy and spread “over-the-top, ultimately ridiculous” claims about clean energy programs.

According to a ThinkProgress analysis of independent advertisements from Kantar Media’s CMAG system, outside conservative groups spent $10.78 million on presidential campaign ads between April 1 and Oct. 1 of this year specifically attacking the Solyndra loan or mentioning Solyndra as part of a broader attack on clean energy stimulus spending.

The ads were purchased by the American Energy Alliance, the American Future Fund, the Koch-backed Americans for Prosperity, Karl Rove’s Crossroads Grassroots Policy Strategies, and Let Freedom Ring.

However, the impact of those Solyndra ads on American voters mirrored the outcome of the yearlong congressional investigation into the company: minimal to nothing.

Despite the millions of dollars spent on Solyndra-related television spots over the last five months, polls show that a majority of American voters still don’t know about the company or are indifferent.

An NBC News/Wall Street Journal poll from early October showed that 58 percent of registered voters are unaware of Solyndra. The poll also found that one-quarter of registered voters had a negative view of the company and 15 percent had a neutral view.

A day earlier, Hart Research released a poll conducted for the Solar Energy Industries Association showing that 67 percent of registered voters are either indifferent about Solyndra or have heard nothing recently about the company. At the same time, 70 percent of voters said they would support more government incentives to help develop the solar industry.

In addition, an April poll from the Pew Research Center found that 52 percent of Americans believe that “alternatives” to fossil fuels are the most important energy priority for the country, with 39 percent saying coal, oil, and gas should be top priorities. That poll also found that conservative Tea Party males — many of whom would never vote for a moderate candidate to begin with — are the only voters likely to view some level of government support for clean energy negatively.

Special interest groups might be buying millions in clean energy attack ads. But voters sure aren’t buying them.

The wave of money promoting lies and hyperbole on clean energy has pushed the political conversation around energy to the extreme. But the actual impact is limited. Americans still overwhelmingly support clean energy, despite what well-armed political groups say.