1. BMWi (2020). Germany on track for meeting eu renew-ables target.
2. Chuang, A.S. and Schwaegerl, C. (2009). Ancillary services for renewable integration. In 2009 CIGRE/IEEE PES Joint Symposium Integration of Wide-Scale Renewable Resources Into the Power Delivery System, 1-1.
3. European Commission (2020). 2020 climate & energy package.
4. Gerdun, P., Ahmed, N., Vernekar, V., Töpfer, M., and Weber, H. (2019). Dynamic operation of a storage power plant (spp) with voltage angle control as ancillary service. In 2019 International Conference on Smart Energy Systems and Technologies (SEST), 1-6.
5. German Environment Agency (2020). Renewable energy share in gross final energy consumption and gross electricity consumption.