AlternaFuture - Final Report
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AlternaFuture has been a multidisciplinary research project in Hydrocen to investigate the potential of extreme upgrading of existing hydropower system with a positive effect on the environmental conditions. The project is a desk study and is carried out through developing future scenarios of an extreme upgrading of an existing hydropower system, to create potential for new innovations and solutions from the multidisciplinary scientists within the project. The existing hydropower system in the Mandal river has been applied as a case-study, where the current situation has been the baseline for developing alterative future scenarios and evaluating the economic and ecological results. The project has been divided in three main activities; (A1) mapping the current situation and defining environmental restrictions for reconstruction, (A2) developing physical scenarios consisting of hydropower projects, environmental projects and use of new innovations, and (A3) economic and environmental evaluation of the scenarios. Three main scenarios were developed for the Mandal river; (1) triple installed capacity, (2) maximum flexibility, and (3) flood protection. The hydropower optimization program ProdRisk was used to compare the hydropower operation and water management in present situation with the three scenarios. Energy price forecasts from HydroCen where used to assess the economic income from hydropower production, which in turn where compared with the estimated construction costs of each scenario to consider the economic feasibility. Thereafter, the impacts on the environmental status and recreational value in different parts of the watercourse, including reservoirs, lakes and river reaches are evaluated for three hydropower scenarios and compared with the present situation. In conclusion, it is found possible to realize extreme upgrading of existing hydropower systems, and at the same time in sum have a positive effect on the environmental conditions. It is noted that the positive effects require a significant effort in mapping and planning the environmental measures. For such upgrading consisting of multiple projects, single projects that have severe negative ecological impacts must be cancelled and cannot be included in the final scheme. Planning of such upgrading projects therefore must include environmental experts from the very beginning. The main conclusions from the AlternaFuture research project are presented below. 1. Extreme upgrading of existing hydropower systems can be done while also in sum improving the environmental conditions. 2. Extreme upgrading of hydropower systems that include pumped storage plants are economically feasible if the energy price variability increases sufficiently. For the Mandal river, the necessary increase is in between the 2030 price forecast and the 2030-scaled forecast as described in Memo 1. 3. It is the pumped storage plants that generate the main increase of revenue in the upgrading scenarios. Extreme upgrading without pumped storage plants has not been found economically feasible for any price forecast. 4. The pumped storage plants result in a reduction of the total energy production for the hydropower system, but a higher income. In the current tax regime, the pumped storage plants result in reduced taxation to the local municipalities because some of the Norwegian hydropower taxes are related to produced energy. The taxation to the central government increases depending on the economic profit from the pumped storage plants. 5. There is potential to find new hydropower projects in existing hydropower systems. 6. It is possible to construct a flood power plant to mitigate the flood challenges in the Mandal river. The flood power plant is not found to be economically feasible only from hydropower production, and the remaining costs have to be financed by other stakeholders such as insurance companies or local municipalities. The flood power plant can reduce a 200-year flood to a 20-year flood. 7. The extreme upgrading scenarios have a positive impact on flood mitigation owing to new reservoirs and pumped storage plants. This positive impact has not been quantified in this project. 8. Recommended future work includes developing a best-practice guideline for environmentally friendly upgrading of existing hydropower systems based on the methodology developed and applied in this project. In addition, 18 new research projects have been proposed and are described in Memo 5.