U.S. Sen. Maria Cantwell, D-Wash., told a solar conference audience Thursday that she will work on policies for building new power transmission lines and allowing consumers to get credits for excess electricity from their solar panels.

Cantwell was one of several politicians and representatives of Sens. Barack Obama and John McCain who used the well-attended Solar Power International in San Diego this week to tout their greentech credentials. California Gov. Arnold Schwarzenegger made a last-minute appearance and said nothing surprising (see Schwarzenegger: Solar Can't be Stopped).

Fresh from helping to pass an eight-year solar tax credits bill, Cantwell was gung-ho about what she plans to tackle in 2009. She talked about the thorny and complex issues that surround building a national electric grid as well as speeding up the approval process for building solar and other renewable energy projects on public lands. She also discussed making a loan-guarantee program that is run by the U.S. Department of Energy available to more mature technologies.

States have traditionally been tasked with regulating utilities and transmission-line projects, and dozens of states also have passed laws to promote renewable energy and energy efficiency technologies through rebates and tax breaks. But that should be changed, Cantwell said.

"We need to rethink the traditional sphere of policy making," Cantwell said. "Some policies can make a big difference in the deployment of renewable sources into the grid. These are policies of national interest."

Anyone who has followed the tortuous process it took to pass those solar tax credits knows that the federal government rarely moves quickly, except in the case of the $700 billion plan to rescue the faltering financial markets. Some would argue that the tax credits wouldn't have gained approval this year if they weren't attached to the bailout plan.

With a worsening economy and talks about using more federal dollars to prop up the financial markets, how likely will legislators be able to support measures that will cost businesses and consumers money to implement?

The growth of renewable energy will require expensive transmission lines because many solar and wind farms are located in sparsely populated areas. To support these new energy sources and the growing demand for electricity, $900 billion will be needed for building the transmission and distribution networks by 2030, according to the Brattle Group.

Cantwell already made it clear that creating a program to trade carbon emissions credits will be difficult. Such a program would require businesses – operators of power plants, refineries and other heavy industries – to buy credits to help them meet emissions requirements.

"Instability of the capital market will be front and center. It will be hard to take up this legislation," Cantwell said.

Convincing utilities and states to go along with a national grid policy will be tough. Cantwell acknowledged that she will have to deal with "touchy and controversial issues."

Getting Republicans to support her efforts also won't be easy. Howard Berke, executive chairman and co-founder of solar-panel maker Konarka Technologies, represented McCain at a debate with Google's Dan Reicher at Solar Power. Berke made it clear that the Republican presidential candidate prefers not to set federal requirements for renewable energy production and use.

"It's difficult to accept a national mandate that will be the right solution for all 50 states," Berke said. "You will find that it will set the lowest bar."