Nearly 2.5 million households (2% of all households!) used wood as their primary residential space heating fuel in 2013, which represents a 38% increase since 2004. About 8% of households use wood as a secondary source of heat in 2013, making wood second only to electricity as a supplemental heating fuel. That’s according to the new U.S. Energy Information Administration Short-Term Energy and Winter Fuels Outlook. Thanks to Pellet Fuels Institute for the information! The full report is available for you to read here as well.