The Indirect Greenhouse Gas Emissions Embedded in the Investment Goods for Emission-Free Power-Generating Technologies, Evaluated for Belgian Conditions

摘要

In absence of direct sources of greenhouse gas (GHG) emissions (combustion), other sources of emissions become dominant in so-called 'emission-free' power plants. In this sutdy the indirect GHG emissions, related to construction of nuclear plants, windfarms and photovoltaic plants, are estimated with two different types of life-cycle-assessment. The process-chain analysis divides an investment-good into its material components (x tons of material A, ...) and then unravels the entire production-process of each material product. The energy required in, and the GHG emissions related to, the construction of the power plant are obtained by integration over all process-steps and summation over all material products. The input/output analysis looks at the different economical sectors called on in the construction of the power plant. Each sector (machinery, construction, service, ...) represents a part of the total cost of the power plant and is responsible for an amount of energy used (and the corresponding GHG emissions) to provide its final product. A result is provided by detailed analysis of all relevant sectors, and fitting them into the construction phase. For construction of these powere plants, the following orders of magnitude are obtained for Belgium: nuclear: 2G_CO2/kWh_el; wind(coast): 8gCO2/kWh_el; hydro: 13 g_CO2/kWh_el; biomass: 12 G_CO2/kWh_el; PV(1996): 140g_CO2/kWh_el; PV(near future): 60g_CO2/kWh_el (g_CO2 stands for CO_2-equivalents emissions).