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Residential Solar Spreading, But Outperformed by Wood Heat

By John Ackerly | July 01, 2013

The U.S. Energy Information Agency recently released 2011 residential energy generation data showing that solar is making gains, and added the equivalent of nearly 40 trillion Btu in 2011. Comparatively, wood and pellet stoves added just 30 trillion Btu in 2011, yet, according to EIA statistics, wood heating still produces three times more energy than solar panels and 11 times more than geothermal.


New EIA projections, however, predict solar may only produce the equivalent of .21 quadrillion Btu of energy in 2040, and that wood heat will produce .45 quadrillion Btu. This assumes a continuation of existing incentive policies that heavily favor solar. How many policymakers know that our government is predicting wood and pellet heating to still double the capacity of residential solar PV, even with all the rebates and incentives? I expect not many.


Residential solar and wood and pellet heat share some key attributes: both are distributed sources of energy powered by the sun. Solar panels convert the sun’s energy directly through photovoltaics, whereas wood and pellet stoves and boilers convert it through photosynthesis, storing it in the tree for later use. They complement each other beautifully, as one produces kilowatts and is inefficient to heat with, while the other produces Btus and is inefficient for electricity.


Solar is typically installed by urban, educated, wealthy families whereas wood and pellet stoves tend to be installed by rural, low- and middle-income families.  Policies that give generous incentives to wealthier families, and not to middle-income families, for their respective technology of choice are based on an array of values, perceptions, assumptions and choices. 


The growth differential is partially due to state, not federal, incentive structures. From 2010 to 2011, 70 percent of the growth in solar occurred primarily in California and Florida, states with healthy incentives. With wood and pellet heating, the growth is far more incremental and organic across many states. Five states provide some state-level incentives for modern U.S. EPA certified stoves, but are far less generous than solar incentives. Even without significant federal or state incentives or rebates, wood and pellet stoves added far more capacity than solar panels between 2006 and 2008. 


The EPA is about to announce new emission regulations for wood and pellet heating equipment, including furnaces and boilers that will be far stricter than existing regulations. Currently, wood and pellet stoves can emit up to 7.5 grams per hour. The EPA has floated a 1.3-gram-an-hour threshold to take effect 5 years after promulgation.  The emergence of cleaner and more efficient wood and pellet equipment is likely to help the growth of wood and pellet heating, as it has in Europe. There is also a green label for wood and pellet equipment being developed in the U.S., to help consumers easily identify the cleanest and most efficient heaters, and enable states to use that label in incentive programs. 


If the U.S. government predicts that residential wood heating will produce double the energy of residential solar PV, does this argue for even more aggressive solar subsidies? I believe we need to build on what works, and that means creating technology-neutral incentive structures. This would allow the consumer to decide what makes the most sense for their situation, based on their values, assumptions, and economic situations. Maine Sens. Angus King and Susan Collins just introduced S. 1007, the Btu Act of 2013, which seeks to include high-efficiency wood and pellet appliances in the provision of the IRS tax code currently giving  a 30 percent consumer tax credit only for solar PV.  Let the consumer decide, not the policymakers who seem to think solar PV is the only solution. 


The cleanest and most efficient wood and pellet appliances deserve incentives, otherwise consumers will likely buy less clean and less efficient appliances, or will keep using existing technology that is often very polluting and inefficient. It is time we guided the wood and pellet sector, as Europe has, maximizing its benefits instead of continuing to rely on outdated equipment.



Author: John Ackerly
President, Alliance for Green Heat
301-841-7755
jackerly@forgreenheat.org