The number of American households using wood as a primary source of heat increased 1.72% this year, continuing a decade long growth spurt for the renewable heating fuel, according to the U.S. Census 2011 American Community Survey (ACS). The survey estimates that 2.11% of U.S. homes use wood-derived fuel as their primary heating source, compared to 2.08% in 2010.
While the growth spurt is continuing, it is also showing signs of slowing down. In the last six years, wood heat showed its greatest uptick in 2005-2006, growing 8.5% in one year. On average from 2000 to 2010, wood grew 4.5% each year, so a 1.7% increase last year may indicate a softening of the market.
The US Census does annual surveys based on sample populations which are then extrapolated to estimate trends in the entire country. The margin of error is higher during these annual surveys than during the decennial surveys where the Census tries to contact all households. The slower rate of rise in wood heat in 2010 may not be connected to the warm winter of 2011-2012 as that winter occurred mostly in 2012.
The ACS does not track secondary heat use, but it is likely that more Americans are using wood to supplement their main fuel as well. According to the 2009 EIA Renewable Energy Consumption Survey, 7.7% of American homes used wood as a supplemental source of heat and wood was the second most common secondary home heating fuel behind electricity. When more homes use wood or pellets as primary heat, the number of homes using it as a secondary heat source grows as well, as far as we know.