Quantifying net water consumption of Norwegian hydropower reservoirs and related aquatic biodiversity impacts in Life Cycle Assessment

Abstract

Compared to conventional energy technologies, hydropower has the lowest carbon emissions per kWh. Therefore, hydropower electricity production can contribute to combat climate change challenges. However, hydropower electricity production may at the same time contribute to environmental impacts and has been characterized as a large water consumer with impacts on aquatic biodiversity. Life Cycle Assessment is not yet able to assess the biodiversity impact of water consumption from hydropower electricity production on a global scale. The first step to assess these biodiversity impacts in Life Cycle Assessment is to quantify the water consumption per kWh energy produced. We calculated catchment-specific net water consumption values for Norway ranging between 0 and 0.012 m3/kWh. Further, we developed the first characterization factors for quantifying the aquatic biodiversity impacts of water consumption in a post-glaciated region. We apply our approach to quantify the biodiversity impact per kWh Norwegian hydropower electricity. Our results vary over six orders of magnitude and highlight the importance of a spatial explicit approach. This study contributes to assessing the biodiversity impacts of water consumption globally in Life Cycle Assessment.