Estimating the environmental costs of the hydro fuel cycle using life cycle assessment techniques and economic valuation.

摘要

A Life Cycle Assessment model, with an integrated impact assessment, is used to estimate average external economic damages from the hydro fuel cycle. Aggregated average damage assessments of the hydro fuel cycle are complementary to marginal and site specific assessments, and are useful for general energy policy planning. For the upstream inventory assessment, detailed material input data from the Morrow Point Dam is used to estimate material inputs at 174 New England, and 4 Quebec, concrete hydroelectric projects. LCNetBase input-output life cycle assessment software, developed by Dr. Gregory Norris at Sylvatica, is used to estimate upstream emissions associated with material inputs and construction activities. Operations-phase emissions assessed include methane (CH4), carbon dioxide (CO2) and methyl mercury (MeHg), which are primarily associated with microbial activity in reservoirs. In the impact assessment, economic valuation is used to estimate the environmental impact associated with emissions from the hydro fuel cycle. Estimates of average externalities are as follows: small NE dams = {dollar}.0343/kWh, medium NE dams = {dollar}.0202/kWh, large NE dams = {dollar}.0193/kWh, Hydro Quebec, La Grande Complex = {dollar}.0461/kWh. Results indicate that the average external impacts from the hydro fuel cycle are less than, but similar to, the external costs from fossil fuel cycles. However, more detailed assessment of individual projects shows that emissions from the majority of hydro projects are very small as compared to fossil fuel cycles. In contrast, site specific characteristics at a small handful of hydro projects greatly exceed emissions per unit of energy for the coal fuel cycle, and increase the average estimates for small, medium and large New England dams.