top of page
Pile of forested logs

Why Wood Heat Should be Incentivized

B. Biomass for Heat is a Low Carbon Renewable Energy

As a low carbon source of energy, residential wood heating has the capacity to play a much larger role in the movement to reduce fossil fuel use in American homes. The sustainable harvest of biomass can accrue environmental benefits as well. This section will discuss the numerous ways in which biomass heat is a low-carbon energy source, a renewable fuel with the substantial capacity to displace fossil fuels, a powerful incentive to keep forests as forests, and a source of other environmentally beneficial effects.

Low Carbon Fuel Source

Biomass for heating use is considered a low-carbon energy source for many reasons. The primary reason is that the carbon released from combustion of wood does not add to the existing atmospheric carbon pool; rather, the carbon released during combustion would have been released due to natural forces of decomposition or forest fire. Given that the forest is managed sustainably, the carbon released from burning wood is re-sequestered by the next generation of growth. Since the scale of residential biomass heat is much smaller than biomass for ethanol or electricity, and has a more favorable carbon profile due to the increased efficiency of utilization for equivalent energy output, the initial ‘carbon debt’ from combusting trees is more easily replaced by sustainable re-growth.1

1 (1).jpg

Figure 14: Carbon Pathways (Washington Forest Protection Association)

While the period between the initial release and re-sequestration of CO2 is a concern, one study that recently explored this issue, the Manomet Center for Conservation Sciences’ ”Study of Wood Biomass Energy” in 2010 suggests that biomass for thermal use is climate positive.2 When paired with highly efficient heating technologies and sustainable forest management regimes, carbon emissions from wood combustion can be short lived in the atmosphere, providing substantial greenhouse gas reduction benefits over time by virtue of reducing fossil fuel use.

Burning fossil fuels takes carbon out of a stabilized form under the ground and introduces it to the mobile carbon pool, resulting in a long-term increase in the net atmospheric concentrations of CO2. On the other hand, burning a tree merely re-releases carbon that was absorbed from the atmosphere during the lifecycle of the organism.4 Because of this, clear definitions of sustainable forest management and effective policies that govern cordwood extraction and pellet production are viewed as an important component for maintaining a robust natural carbon cycle and thus ensuring that the low carbon benefits of wood heat are realized.

"Clearly, burning this wood for domestic heating is likely to result in very little net emission of CO2 per unit of energy generated."3

Renewable Energy Source/Displaces fossil fuels

Sustainable harvesting ensures the fuel used for heating is replaced with new growth. Questions of carbon aside, wood is an energy source that can be regenerated with sustainable forestry.

Fossil fuels combusted for energy are the largest source of greenhouse gases being added to the atmospheric carbon pool, and are the origin of many other pollutants such as the sulfur, which can result in acid rain. The destructive extraction methods of traditional fossil fuels pose an additional threat on top of the pollutants.5 The forestry activity associated with cord wood and pellet production has a very small environmental footprint and avoids negative impacts associated with the production of fossil fuels.

2 (1).jpg
3 (1).jpg
4 (2).jpg

Figure 15: Air emissions from residential heating: The wood heating option put into environmental perspective (EPA)6
Note: the results in all of these graphs reflect the energy trajectory of the fuels rather than just end point emissions

It is notable that wood heat has the lowest emissions of greenhouse gases among the home heating fuels (Fig. 14). The greenhouse gas emissions from the study, Air Emissions from Residential Heating are conservative in the estimate of the benefits of wood burning for CO2 reduction. Rather than assuming a nearly carbon-neutral cycle, the study reduced the CO2 emissions from wood by a reasonable 40% based on current standard wood harvesting practices (including the fossil fuels used to transport and process the wood).

Supports Responsible Forest Management

Consumer demand for fuelwood can create new markets for wood products, which can make it economically viable to remove trees that might otherwise have no value.

“The harvest and use of trees damaged by insects or thinning forests to reduce wildfires is the proverbial win-win-win of improving forest health, creating employment opportunities and producing a clean energy source.” –Al Steel, Forest Service Scientist, USDA Forest Service

5 (1).jpg

Figure 16: Pine bark beetle killed forest, Colorado (The Colorado Independent)

The wood heat industry can support forestry management activities such as controlling invasive species or mitigating fire hazards through forest thinning by providing a market for low value trees that provides enough money to help defray the often large expenses that these operations can incur. 7 8Reducing harvesting activities for the purpose of storing carbon can backfire by increasing the risk of a devastating forest fire or insect outbreak that would remove far more healthy trees than well planned cordwood harvest.9 Montana State Department of Natural Resources, for example, provides firewood permits (for a small fee) with a two cord minimum harvest in order to help the state manage the pine bark beetle killed trees.10

“Small diameter, crooked stem, or low value species that might be targeted for removal, often bring little or no value in the market place. This problem of finding markets for this material has been identified as a key goal by the landowners of the Massachusetts Woodland Cooperative.”- David Damery, Journal of Sustainable Forestry

Provides a Financial Incentive to Conserve Forests as Forests

Firewood harvesting provides an important revenue stream for many landowners, large and small which increases the financial incentives to retain forest land as forest land. 11One of the primary causes of U.S. forest loss is the transformation of privately owned forests to development. 12Pre-recession estimates showed that nearly 6,000 acres of forest and open space are converted to other uses in the US on a daily basis. 13Firewood harvesting provides an additional financial value to maintain forestland in its undeveloped state.

Additional Benefits

Biomass Heat has numerous other environmental benefits as well. Because cordwood is necessarily a local fuel source, the carbon footprint associated with transporting it to the end user is quite low14. Residential heating applications can also utilize low value sources of wood like sawdust and urban wood waste for pellet creation, thus preventing them from ending up in landfills. The value that residential wood heating bestows upon these types of materials also provides economic support for the local municipalities and the forest products industries that provide them. Finally, using wood in one or more stoves can heat the home very efficiently by providing warmth to the most used parts of the home. This is known as ‘zone heating’ and it can significantly save fossil fuel because the low traffic parts of the home are not heated as aggressively as the most used areas.

1 Walker et al. Biomass Sustainability and Carbon Policy Study. Manomet Center for Conservation Sciences. June 2010. Pg 7
2 Walker et al. 2010. Pg 7
3 Paul K. et al. Net Carbon Dioxide Emissions from Alternative Firewood-production Systems in Australia. Biomass and Bioenergy 30. January 2006. Pg 644
4 “Biomass: A Key Source of Renewable Energy.” <http://www.wfpa.org/pages/biomasspolicy.html>
5 Hester & Harrison. Pg 7.
6 U.S. EPA and Air Waste Management Association Conference. Emission Inventory: Living in a Global Environment, v. 1, pp 373-384, 1998. <http://basineducation.uwex.edu/centralwis/pdfs/hpawma.pdf>
7 Tsai, Katherine. Forest Service keeps eye on timber industry health. Associated Press. November, 2010.
8 Arnosti, D., D. Abbas, D. Current, and M. Demchik. Harvesting Fuel: Cutting Costs and Reducing Forest Fire Hazards through Biomass Harvest. Institute for Agriculture and Trade Policy, Minneapolis, MN. 2008. Pg 8
9 Canadell, Josep, Raupach, Michael. Managing Forests for Climate Change Mitigation. Science. Vol 320. June 13. 2008. Pg 1456
10 Montana Department of Natural Resources and Conservation. Sept. 2007. <http://dnrc.mt.gov/news/news_releases/2007/14Sept07.asp>
11 Damery D. Landowner Driven Sustainable Forest Management and Value-Added Processing. Universitiy of Massachusetts Amherst. 2005. < http://bct.eco.umass.edu/publications/by-title/landowner-driven-sustainable-forest-management-and-value-added-processing/>
12 Stein et al. Forests on the edge: housing development on America’s private forests. Gen. Tech. Rep. PNW-GTR-636. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 2005. Pg 16.
13 Butler, B. (2008) Private forest landowners in the United States, 2006. Newtown Square
14 Calculations may be higher with pellet fuel, which requires greater energy investment to process, although their densified nature can allow for enhanced shipping efficiency

bottom of page