Integration of large-scale wind power and use of energy storage in the Netherlands' electricity supply

Abstract
The use of energy storage for increased operational flexibility is commonly regarded as a logical complement for systems with large amounts of wind power. The authors explore, the opportunities for energy storage for the integration of large-scale wind power into a future lay-out of the Dutch generation system, for which minimum-load problems are foreseen with high wind power penetrations. A central unit commitment and economic despatch model is extended with models for three large-scale energy storage technologies: pumped hydro accumulation storage (PAC), underground PAC and compressed air energy storage. Furthermore, an alternative solution is investigated, comprising the installation of heat boilers at selected combined heat and power locations (CHP) in order to increase the operational flexibility of these units. Results are shown for different wind power penetrations and scenarios. A cost–benefit analysis shows that the operation cost savings from energy storage increase with the amount of wind power installed. Taking into account the large investment costs, energy storage units are however unlikely to have a profitable exploitation. The installation of heat boilers at CHP locations is found to be more efficient and a promising solution for the integration of large-scale wind power in the Netherlands. A notable result is that for the Dutch system, the use of energy storage increases the system's overall CO2 emission levels because energy storage allows storing power from cheap coal plants for substitution of expensive gas during peak. Even though often proposed as a solution for wind power integration, energy storage in fact partly annuls CO2 emission savings by wind power.