by Christina Whalen
Producing electricity from biomass could potentially provide a back-up storage source for the intermittency that accompanies wind and solar energy production. Biomass electricity also provides a carbon-negative and efficient method for bioenergy production, which is important because of mandated restrictions on carbon emissions. Furthermore, biomass electricity also provides an efficient method for providing renewable transportation energy that could replace current liquid fuel approaches. Although bioenergy may be important in producing electricity and developing energy storage mechanisms, the economic and environmental effects are unclear. Studies have been conducted on abandoned agricultural lands to try to find a path of producing bioenergy that has reduced land impact. Campbell et al. estimate at county level, the magnitude and distribution of abandoned agricultural lands in the United States and attempt to quantify how much potential energy storage could be produced by the provided bioenergy.
GIS-modeling was used to develop maps of availability, biomass yields, and bioenergy production of the US counties studied. Abandoned agricultural lands were further divided into abandoned croplands and abandoned pastures. The new cropland estimates were compared to previous estimates based on data from other global gridded databases. Seasonal energy storage requirements were estimated using data from current electricity demand, wind production, and solar production from the Department of Energy’s (DOE) Energy Information Administration (EIA). Annual storage requirement is the storage capacity that is required to counterbalance energy deficits that result from seasonal intermittency. The current abandoned cropland estimate is 71 million hectares (Mha), which is about 41% of current cropland area.
The high-resolution land-use databases provided a 61% larger area estimate of abandoned croplands than previous studies reported. This large estimate resulted from using more spatially resolved data. The results also suggest that there is a larger uncertainty in abandoned agriculture than previous studies concluded. Future analysis and studies of bioenergy potential should consider availability of land resources, yield estimates, and energy conversion efficiencies. The collected data were used to consider the role of bioenergy in seasonal energy storage, which is necessary because of the intermittency of future energy production based on wind and solar energy. The results demonstrate that bioenergy could provide most seasonal storage requirements, but that a system dominated by solar energy requires positive assumptions about biomass yields to completely satisfy the energy storage requirement.
Campbell, J., Lobell, D., Genova, R., Zumkehr, A., Field, C. 2013. Seasonal energy storage using bioenergy production from abandoned croplands. Environmental Research Letters 8, 1–7. http://iopscience.iop.org/1748-9326/8/3/035012/article