Clean energy use is at its highest level since the Depression by Katie Fehrenbacher @FortuneMagazine May 28, 2015, 8:48 PM EDT E-mail Tweet Facebook Google Plus Linkedin Share icons A building boom in solar and wind farms as well as the increasing use of biofuels in vehicles pushed renewable energy to nearly 10% of overall U.S. consumption last year, according to the Energy Information Administration. That’s the highest share since the 1930s, when wood burning stoves and wood used for industrial purposes was popular. Yes, the government considers burning wood to be renewable energy. Most people define clean energy as coming from carbon-free sources like solar, wind, and hydroelectric dams and generating electricity. But the EIA has a broader definition that includes energy generated from biomass and biofuels. That means ethanol used to fill up certain cars and wood pellets used to power industrial plants are counted as renewable energy. Oddly, wood for heating homes in rural areas is also counted. A rainbow forms behind giant windmills near rain-soaked Interstate 10 near Palm Springs, Calif.David McNew—Getty Images Still, electricity remains the biggest slice of the renewable pie with nearly half of all clean energy going to electricity, from solar, wind power and hydropower. But electricity generated from natural gas and coal dwarfs electricity made from renewables. In fact, clean energy only accounted for 13% of all of U.S. electricity consumption. The solar industry had a record year in 2014, growing over 34% from the previous year, according to the Solar Energy Industries Association. There are now more than 20 gigawatts of solar projects in the U.S. (1 gigawatt is like a really big natural gas, coal or nuclear plant), or enough to power more than 4 million average American homes. Their numbers continue to grow quickly. Last year, the SEIA says that there were 195,000 new solar projects installed. As for the wind industry, four times more capacity came online in 2014 than it did in the previous year, says the American Wind Energy Association. The industry added 23,000 jobs in 2014 for a total of 73,000. States like Iowa with a lot of natural wind assets can power almost a third of the state’s electricity with wind.