Hydropower Results – Life Cycle Assessment Review
To clarify the state of knowledge on hydropower systems, NREL completed a comprehensive review and analysis of life cycle assessments on run of river, reservoir, and pumped storage hydropower systems published between 1980 and 2010.
The figure below summarizes the results of the systematic review and analysis. The majority of life cycle greenhouse gas (GHG) emission estimates for hydropower cluster between about 4 and 14 g CO2eq/kWh.
The outliers, which show reservoir hydropower estimates of over 150 g CO2eq/kWh—much higher than run-of-river or pumped storage—stem from studies that included assessments of GHG emissions from land use change (LUC) from reservoir hydropower, an area of active research. In comparison to fossil energy generation technologies, the life cycle GHG emissions from hydropower systems are low. Additional life cycle assessments on all hydropower technologies are needed to increase the number of estimates and the breadth of their coverage in terms of climatic zones, pre-impoundment land cover type, technology types, and dam sizes.