European Case Study: Frequency reserves from wind power and PV in a large footprint: D5.4

This report is part of the EU-funded REserviceS project on ancillary services from wind power and PV (variable generation, VG). Several case studies were done studying procurement possibilities and the economics of ancillary services from VG. In this European case study ancillary services at transmission level are studied for a relatively large footprint containing Germany, Poland, Netherlands, Belgium, France, Great Britain, Denmark, Norway, Sweden and Finland. As the focus of the project is on future provision of ancillary services, scenarios with high annual penetration of variable generation (32%, 42% and 50%) were studied. Voltage-related ancillary services were not analysed, since the large footprint of the case study did not allow for the level of detail required for voltage management analysis. The results demonstrate that, if allowed, variable generation will replace considerable amounts of conventional generation from the frequency reserves. This will decrease curtailments of variable generation. This case study confirms the more detailed work in the REserviceS Iberian case study (D5.3): considerable economic benefits can be made from the use of variable generation in the frequency reserves. This case study also assessed the benefits of cross-border sharing of frequency reserves and compared them with the benefits of using variable generation for frequency reserves. Both of these approaches produce similar benefits. Utilising both of them concurrently gives a further increase in the benefits. The largest benefits were observed in the downward frequency containment reserve and in the automatic frequency restoration reserve. Upward frequency containment reserve was not as beneficial. The results indicate that it is not necessary to have frequency control capability in most offshore wind power plants, but due to the large study footprint and the consequent aggregation, it is not possible to be definitive about specific circumstances.