Hydropower's Biogenic Carbon Footprint

• DOI: 10.1371/journal.pone.0161947
• Publication Date: 2016-09-14T13:30:02Z
• Authors: Laura Scherer; Stephan Pfister
• Keywords: Carbon Footprint; Hydroelectricity; Energy source

Global warming is accelerating and the world urgently needs a shift to clean renewable energy. Hydropower currently largest source of electricity, but its contribution climate change mitigation not yet fully understood. Hydroelectric reservoirs are biogenic greenhouse gases in individual cases can reach same emission rates as thermal power plants. Little known about severity their emissions at global scale. Here we show that carbon footprint hydropower far higher than previously assumed, with average 173 kg CO2 2.95 CH4 emitted per MWh electricity produced. This results combined 273 CO2e/MWh when using potential over time horizon 100 years (GWP100). Nonetheless, this still below fossil energy sources without use capture sequestration technologies. We identified dams most promising for capturing methane alternative source. The spread among ~1500 plants analysed study large highlights importance case-by-case examinations.