Greenhouse Gases from Geothermal Power Production

Fridriksson, Thrá ; inn ; Mateos, Almudena ; Audinet, Pierre ; Orucu, Yasemin

World Bank, Washington, DC

关键词: GLOBAL WARMING POTENTIAL;    CALCIUM;    PHOTOSYNTHESIS;    CO2 FLUX;    TOTAL EMISSIONS;   

RP-ID  :  106570

学科分类：社会科学、人文和艺术（综合）

来源: World Bank Open Knowledge Repository

【 摘 要 】

Geothermal is a renewable source energythat can be used directly for heating or for powerproduction. Geothermal utilization, particularly powerproduction, may result in some greenhouse gas (GHG)emissions. GHG emissions from geothermal power production isgenerally small in comparison to traditional base loadthermal energy power generation facilities. This is mainlydue to the fact that the large majority of installationsdraw their geothermal energy from geothermal reservoirs withlow GHG concentrations. However, as the geothermal sectorhas expanded, a wider range of geothermal resources havebeen brought into exploitation, including geothermal systemswith relatively high GHG concentrations in the reservoirfluid. There is a growing realization within the geothermalcommunity that geothermal power plants can, in rareinstances, release significant quantities GHG into theatmosphere. This interim technical note presents an overviewof the current knowledge on GHG emissions from geothermalsystems and geothermal power plants, and gives guidance onhow to assess GHG emissions from geothermal projects whenthis is required, depending on their stage of development.This note identifies critical knowledge gaps and presentsrecommendations as to how close these gaps and proposes aninterim methodology to estimate GHG emissions fromgeothermal projects that financing institutions, such as theWorld Bank, intend to support. The plan is to update thisnote when the methodology has been tested by application toactual projects and some of the current knowledge gaps havebeen closed as more information become available. This noteproposes a way to estimate future emission factors forgeothermal projects under development. For instance, if apumped binary power plant is planned, the emission factorwill be 0. Projects using other energy conversiontechnologies will result in some emissions. For projectswhere wells have been drilled and tested, formulas areprovided to compute emission factors based on the chemicalcomposition of the geothermal fluid and the designparameters of the power plant. For projects located in thevicinity of existing power plants in analogous geologicsettings, emission factors from the existing plants can be used.