Feasibility analysis of capacity expansion in Skjerka power station based on production simulation in ProdRisk.

Abstract

The Norwegian energy system has traditionally had an energy surplus with a large share of hydro power. Due to increasing demand of power from large scale electrification, the power system is estimated to experience hours of national power deficient in 2030 even with moderate increase of consumption. Extensive increase of variable production renewable power from wind and solar in Northern Europe has led to increased volatility in power prices and a need for larger amounts of balancing power. This thesis will research, through a socioeconomic perspective, the feasibility of two expansion alternatives with the net present value method: a 100 MW Francis turbine expansion or 100 MW reversible pump turbine expansion. Results are obtained through simulations by the optimization program ProdRisk, given three price scenarios with varying volatility and fixed average price. Simulations results indicates increased revenue when volatility increases. Pump usage of the reversible pump turbine also increases in line with volatility and leads to larger gross energy production and revenue compared to a Francis turbine expansion of the same installed capacity. The economic analysis utilizes the revenue and energy production difference compared to a reference simulation of todays installed capacity at Skjerka power station, of 200 MW. Due to the project investment cost, the only net present values that proved to be feasible where the ones obtained from the price scenario with largest volatility. The reversible pump turbine expansion proved to be the most feasible option using the results obtained in simulations, despite having a higher investment cost compared to a Francis expansion. In addition, it has the ability to be used in pump mode, thus providing valuable balancing power for an improved transition to a power system with larger share of variable renewables.