Those loan guarantees will change how developers of wind, solar, geothermal and hydropower projects finance their construction, which in turn will determine returns for investors such as GE's EFS.
"In this environment, no one's going to get (financing) approval to do anything now," Tim Howell, head of EFS' power and renewable energy business, told Reuters in an interview.
EFS has $4 billion to spend on new energy projects, including renewables and conventional power plants, such as gas-fired generation, he said.
The company will be able to move more quickly with its equity investments than banks using debt financing for projects, he said. Debt financing typically takes at least two months to put in place.
Still, with the turbulence in the financial markets, Howell said there was not likely to be a flood of new renewable projects announced once the government's rules were released.
"I don't think that there is the capacity in debt or equity markets to just turn this on like a spigot," he said.
In April, EFS invested more than $200 million with Noble Environmental Power for 330 megawatts of wind power in New York State and has said it was considering buying into a 300 MW wind farm in British Columbia, Canada with Plutonic Power Corp, with whom it has also partnered for hydropower projects.
Wind power, which made up more than 40 percent of the new electricity generation built in the United States last year, remains the most competitive renewable energy versus conventional power sources, Howell said, but photovoltaic solar power costs were dropping fast and closing the gap with wind power.
"We'd love to do more solar, but it's tough because there aren't that many deals of scale," he said.
Most of the biggest U.S. solar projects have been financed by regulated utilities who have strong balance sheets they can leverage.
Still, EFS has linked up with solar power maker SunPower Corp for a 2.2 MW project that put solar panels on a California jail and two wastewater treatment plants under a deal in which SunPower sold the electricity output through long-term power purchase agreements.
EFS is also wary of concentrated solar power plants, which focus sunlight with mirrors to produce heat used to run a conventional electricity turbine.
"Concentrated solar is having a tough time getting out the starting blocks," he said, largely because of the complexity of the financing needed to fund the projects.