Despite the economic slowdown and the absence of any groundbreaking climate policy, renewable energy had a good year in the United States in 2011. According to the latest report from the Energy Information Administration, the government’s keeper of all energy-related facts, renewables grew at a record pace and squeaked out of last place in the country’s energy generation standings. In the first nine months of the year, renewables accounted for 11.95 percent of domestic energy production, pulling ahead of nuclear power, which contributed only 10.62 percent.

When you look at the electricity sector alone, renewables shine even brighter. Nuclear’s share of electricity generation dropped by 2.8 percent compared to the first nine months of 2010, while coal’s share dropped by 4.2 percent. In the same period, renewables’ share of electricity generation grew almost 25 percent.

Renewables’ big bump comes is attributable in part to its relatively small share of electricity generation overall. But the continuing success of renewable energy also points to its dynamism compared to energy sources like nuclear plants—which take years to build, require heavy investments at the beginning of their lifetime, and often face strong community opposition. While the price per unit of renewable energy has been dropping steadily, the price per unit nuclear energy has been sneaking upward.

Some supporters of renewables do see a role for nuclear energy in a low-carbon future. It is, after all, clean energy, and it poses little risk to human life and health compared to coal power. The nuclear industry is looking for different ways to build plants—new designs use nuclear waste for fuel, for instance, and plans for "mini-reactors" could make nuclear power a less-intimidating investment.

Nuclear power, though, is stuck between its past and its future; renewable energy is thriving now, and its share of power generation should continue to grow over the coming decades. For the foreseeable future, that trend might require support from the government: If Congress decides to keep rolling back subsidies, the solar and wind industry worry that growth could stall out. But private financiers are starting to realize that solar installations are strong investments that deliver steady, predictable profits, and the solar industry is starting to envision a time when its momentum won’t depend on the whims of Washington.

Right now, an agency like the EIA groups all renewables together under the same heading, and last-generation technologies like hydro power and biomass are helping to boost upstarts like wind and solar into the big leagues. But these newer energy sources are growing steadily. The larger the contribution they’re making to the country’s power, the more seriously policymakers and investors will have to take them.

Photo via (cc) Flickr user Jasmic