A TOTAL FUEL-CYCLE APPROACH TO REDUCING GREENHOUSE-GAS EMISSIONS - SOLAR GENERATION TECHNOLOGIES AS GREENHOUSE-GAS OFFSETS IN US UTILITY SYSTEMS

Greenhouse gas emissions in the electric utility sector occur not only at generation facilities, but also during upstream processes that sup port the construction and operation of energy facilities. A total fuel cycle approach is used to evaluate the potential greenhouse gas savin gs that could result from the deployment of solar generation technolog ies in utility systems in the United States. Total fuel cycle analyses were completed for several renewable and conventional generation tech nologies to estimate the total greenhouse gas emission contribution fr om each generation technology. These results are used to develop total fuel cycle emission rates for planned electric capacity additions in the U.S., and these rates are compared with the emission rates that wo uld occur if solar technologies were substituted for fossil generation capacity additions. Current projections for solar technology deployme nt are low relative to total capacity additions. Hence, even doubling the planned additions of solar technologies produces less than a 1% re duction in annual CO2 and CH4 emissions from new generation. However, the total lifetime greenhouse gas savings from increased deployment of solar technologies can be substantial. Increasing planned solar deplo yment by only 25% up to the year 2010 can create up to six million ton s of CO2 savings over the lifetime of the solar installations. (C) 199 7 Elsevier Science Ltd.