Prior to the growth of production and distribution networks for petroleum and other fossil fuels in the early 20th century, many homes used wood for heating as did industry. This reliance on renewable biomass historically satisfied a significant portion of the total domestic energy demand. But technological advances and the birth of the electric power industry led to greater use of other fuels. As a result, the EIA reports that renewable resources' share of total domestic energy supply peaked in the 1930s, then declined.
But recent growth in U.S. renewable energy use has brought the country's energy mix back to nearly 10% renewable. Indeed, from 2001 to 2014, renewable energy use grew an average of 5% per year, largely through increased use of wind, solar, and biofuels:
- Wind energy grew from 70 trillion Btu in 2001 to more than 1,700 trillion Btu in 2014.
- Solar energy (solar thermal and photovoltaic) grew from 64 trillion Btu to 427 trillion Btu.
- The use of biomass for the production of biofuels grew from 253 trillion Btu to 2,068 trillion Btu.