Analysis of the Profitability of Energy Storage for RES in an Equilibrium Model of the Power Market

Abstract

The motivation behind this thesis is to utilize complementarity conditions to assess the applications of energy storage in an energy system with high levels of renewable energy sources. A model of a perfectly competitive power market has been developed based on complementarity theory. The model includes firm demand, system operator, power producers and storage units. In addition, four different capacity remuneration schemes have been implemented: Energy only, strategic reserves, capacity market and capacity payment. These models have been subjected to a scenario with high levels of renewable energy in order to assess the impact of energy storage in these circumstances.

The methods used in this work are theoretical and highly dependent on the assumptions and parameters used. The documentation should give a good insight to complementarity modeling in general as well as describing the entire model all the way up to the full mixed complementarity problem formulation.

A large part of this work has consisted of improving the existing model from the project work and develop and integrate the energy storage with the rest of the model.

The findings show that the system can benefit from energy storage options. In general, energy storage will give better conditions to base load units such as nuclear power. The energy storage will smooth over variations and increase the amount of capacity a base load unit can run for a large portion of the year. Utilizing Norwegian hydro reservoirs for pumped hydro applications was found to be the most effective storage unit, increasing the amount of nuclear power by 18.8%. Pumped hydro was found to shift energy between large periods while the battery was found to arbitrage prices on a shorter term. This thesis can give an insight into which barriers need to be overcome in order to ensure investments in energy storage. For example high fixed costs of the storage and unfavorable conditions compared to thermal plants in a capacity remuneration mechanism can be the determining factor resulting in low or no installed storage capacity.