A System Dynamics Study of Carbon Cycling and ElectricityGeneration from Energy Crops

摘要

The Climate Stewardship Act, a global warming mitigation policy calling for a cap-andtradeprogram, was reintroduced in the United States Senate this year. The EnergyInformation Administration analyzed the implications of the bill and found that undersuch a policy renewable energy will increase, with the strongest response coming frombiomass energy. Dedicated energy crops are one source of biomass that is expectedto contribute significantly to the future biomass energy supply. This paper describes asystem dynamics model of the carbon impacts from a dedicated energy crop. Thework relies on another carbon accounting model, GORCAM, which uses spreadsheetmodeling to investigate various land management regimes. We were able toreproduce the GORCAM results for a 20-year harvest rotation; we then simulatedseveral different harvesting intervals to gain insight into the carbon impacts of theserotations. Our results show that using energy crops to displace coal in electricitygeneration will have greater impacts on reducing atmospheric carbon than simplyplanting the crop for carbon sequestration. Furthermore, the harvest interval withoptimal carbon benefits was found to be 9 years. These results agree with previouswork that found long-term benefits were greater for scenarios where trees wereplanted for energy generation rather than specifically for carbon sequestration.