The life-cycle water footprint of two hydropower projects in Norway

The life-cycle water consumption is calculated for two Norwegian hydropower plants, one is a typical run-of-river plant located in southern Norway (Embretsfoss 4) and the second a reservoir-based plant located in mid-Norway (Trollheim). Applying the net evaporation approach, the water consumption values are 0.15 l/kWh for Embretsfoss 4 and 0.19 l/kWh for Trollheim, which are very low compared to earlier published studies. Dividing the life-cycle phases, the water consumption originating from the operational phase constitutes of 37.9% for Embretsfoss 4 and 84.5% for Trollheim of the total net water consumption. The net water consumption rates are very low compared to the gross rates for the two projects, i.e. only 0.2% for Embretsfoss 4 and 4.2% for Trollheim and much lower than similar comparative studies. The water consumption is further regionalized and the impact calculated by use of five different characterizations ('water-scarcity') methods, lowering the water consumption rates further due to the low characterization factors of Norway. Three of the five applied methods and the life-cycle inventory (LCI) provide a consistent picture with respect to the relative contribution of water consumption from the various elements of the life-cycle phases.

The spatial boundaries of the study are set wider than most similar studies, by including a larger part of the regulated system than only the power plant and the reservoir located in the immediate vicinity of the plant. According the authors' knowledge, this is also the first well-documented study comparing the water consumption from the various lifecycle phases. Copyright © 2015 Elsevier Ltd. All rights reserved.