Accounting for GHG net reservoir emissions of hydropower in Ecuador

Hydropower is one of most important considered renewable technologies to provide electricity generation worldwide. Bearing in mind the lack of LCA studies and the development of several hydroelectric projects in Ecuador, the purpose of this paper is to present a complete environmental performance of two hydropower schemes (dam and run-of-river) located in this country, through the life cycle assessment combined with reservoir GHG emissions approach. The run-of-river scheme had better environmental performance than the dam scheme. Very high emissions were found, being 547 Kg CO2-eq/MWh for dam scheme, which most of those emissions were originated in the reservoir, while the run-of-river scheme only score 2.6 Kg CO2-eq/MWh. However, comparing with fossil fuel power plants, hydropower dam case still has lower emissions in its entire life cycle. The paper remark that the majority of LCA studies which focus on dam hydropower scheme only consider the emissions of the construction, putting aside the loss of the ecosystem and the emissions caused by the impoundment. Moreover, the analysis also included the impact associated to water uses since reservoirs are usually devoted to several purposes (flood lamination, irrigation, ecological flow, power generation).