Optimal water allocation for an alpine hydropower system under changing scenarios

The operating rules of water allocation in the alpine OFIMA hydropower network of the Maggia River basin (Canton Tessin, Switzerland) are investigated in response to changes in the production policy and environmental and climatic factors. The study was carried out by means of a nonlinear programming approach where the objective function is approximated to a quadratic form with linear constraints, and implemented on a monthly time scale. Two system configurations with different details were accordingly investigated and compared to assess the response of the hydropower network to changes in the production policy, in the magnitude of the inflows and to different environmental requests. The optimal solution of water allocation corresponding to the new hypothetical production policy shows marked differences but similar benefits when compared to the one of the present operating rules, thus suggesting the good flexibility of the real network under such change. In its whole, this paper therefore highlights the importance of supporting strategic decisions by means of informatics tools and, in addition, it provides a useful case study to test the performances of the software AQUARIUS implementing such a nonlinear programming technique.