Biomass carbon emissions 115% lower than natural gas

A new study argues that carbon emissions are drastically lower when biomass is used to generate electricity instead of natural gas.

The new research was commissioned by the US Biomass Power Association. Dr. Madhu Khanna, professor in Environmental Economics at the University of Illinois, and Dr. Puneet Dwivedi, assistant professor in Sustainability Sciences at the University of Georgia, analysed the carbon intensity of a forest residue fuelled 50 megawatt biomass power facility in New Hampshire, and compared it with a typical combined cycle natural gas facility.

It was found that the biomass plant offered immediate carbon savings of 115%, with 98% savings over a hundred years.

The plant at the heart of the study uses organic residues to generate power supplied to the electricity grid. The fuels used at this facility are residues leftover from harvesting fibre for local lumber and paper mills: tops, limbs and other forestry byproducts. If not used by biomass power plants, these low-value, “waste-like” materials typically remain in the forest as slash piles.

Khanna and Dwivedi’s study took into account the rate of decay of forest biomass, and the carbon and methane emissions that would have occurred had the materials been left to decay on the forest floor instead of being used in power generation. Incidental carbon emissions from the harvesting, chipping and transportation phases were also accounted for.

The authors conclude that removing waste materials that decay from the forest floor and using them in biomass plants leads to a drastic reduction in greenhouse gas emissions. The natural decay of these materials on forest floors releases small amounts of methane consistently over a long period of time, with the global warming impact of methane gas 21 times higher than carbon dioxide.