Samhällsekonomisk lönsamhetsbedömning av miljöåtgärder vid Älvkarleby vattenkraftverk, Dalälven

Sammanfattning: The Swedish hydropower needs to be adapted to new legislation requiring modern environmental conditions according to the EU Water Framework Directive. A national strategy suggests how to balance the need for improved ecological status to the need of hydropower and was submitted to the Government in October 2019. To make the adaption towards sustainable hydropower in Sweden, the Älvkarleby power plant needs environmental measures as fish passages to improve connectivity as well as an environmental flow in Kungsådran. The Water Authorities suggests environmental measures in Älvkarleby consisting of a nature-like fishway for the fish to move upstream, a net for guiding the fish downstream and an increased flow in Kungsådran to 20 and 30 m3/s for winter and summer, respectively. In addition, suggestions of measures have been formed by Vattenfall based on the results of a pilot study in the Dal river creating eight scenarios. The scenarios consist of combinations of two different techniques for fish passages (nature-like fishway and a technical fishway), two techniques for guiding the fish downstream (angled bar racks and a net) and two suggestions of flows in Kungsådran; keep the flow in today’s level of an average of 3 and 12 m3/s (for winter and summer, respectively) or 7.5 m3/s all year. In this study, the suggested measures are valued in a cost-benefit analysis (CBA), that includes all expected consequences for the suggestions given in the chosen time periods, to evaluate their socio-economic profitability. A CBA tool based on a research project called FRAM-KLIV is used to receive the net present value of the suggested measures. The results show that the measure suggested by the Water Authorities is not found to be socio-economic profitable, when compared to today. This analysis has not been able to monetarize two of the identified consequences. In the CBA eight scenarios are compared to the suggested measure by the Water Authorities, Scenario 1 is valued to be the most socio-economic profitable. Moreover, there are only two Scenarios (number 4 and 8) that is evaluated to not be socio-economic profitable. In this part there is one identified consequence that has not been monetarized. There are uncertainties in the methods of estimating the consequences, which are used as input in the CBA tool, thus affecting the result. In conclusion, to have a trustworthy result there is a need of more thorough investigation for the evaluation to be used in decision making of which measure is valuated to be socio-economic profitable.