Is forest-biomass electricity carbon neutral?

At The Energy Co-op, we only offer electricity from wind and solar projects. However, another form of renewable energy has been in the news recently: Biomass power – electricity generated by burning wood in power plants instead of coal – accounts for approximately 1.6% of US electricity generation and is increasingly used by states in the Southeast to meet renewable energy targets.

Wood, unlike coal, can be a renewable resource if the forests supplying that resource are managed sustainably. As long as the cycle is closed – i.e., forests that supply wood fuels are regrown – then the carbon released when the wood is burned to generate power should ultimately be reabsorbed which would make the cycle carbon neutral (not including any emissions associated with harvest, processing and transportation of wood fuels). The policy memo released by the EPA in April codifies this view on the carbon neutrality of biomass paving the way for the continued use of biomass as a strategy to meet renewable energy targets.

Despite the EPA’s finding, there are many stakeholders who are not convinced that biomass delivers carbon benefits. Non-profits such as the Dogwood Alliance and the Natural Resources Defense Council contend that biomass power is at least as carbon intensive as coal-fired generation. The core of their concern has to do with the timing of emissions – while trees may ultimately regrow and reabsorb carbon, during the intervening decades between harvest and regrowth to a mature forest, carbon concentrations in the atmosphere will be affected by the use of this energy resource.

Fundamentally, both sides are right. Over time, assuming the forests that supply the biomass fuels are regrown, carbon emissions should balance out. However, in the short term, it is possible that far more carbon will be added to the atmosphere than would be the case were the same electricity generated by wind or solar. At the moment, woody biomass is a very small player in Pennsylvania – there is only one power plant in the state that relies solely upon wood as a feedstock – but it is an interesting issue to follow as it illustrates the complexity of transitioning away from fossil fuels.