The impact of operating reserves on investment planning of renewable power systems

To limit computational effort, current power system expansion planning tools typically consider limited detail on the technical constraints of power systems, such as the need for operating reserves. With growing balancing needs, this is likely to underestimate the technical barriers and integration cost of large shares of renewable generation. This contribution studies the impact of operating reserve requirements on generation capacity investments following the large-scale integration of intermittent renewable generation. Simulations show that operating reserves have a substantial impact on the generation capacity installed, and its operation, and result in a substantial increase of renewable integration costs. Furthermore, it is shown that the use of improved reserve strategies, such as dynamic reserve sizing, and the participation of renewables in the supply of downward reserves, is able to significantly reduce this cost increase.