Future Perspectives of Electrical Energy Supply -- Existing Energy System Studies -- Demand for Balancing Electrical Energy and Power -- Technologies for Balancing Electrical Energy and Power -- Technology of Electricity Networks, Economical Impacts and Policy -- Legal Analysis of Balancing Strategies -- Analysis of Economic Impacts -- Conclusions and Recommendations.

A significant problem of integrating renewable energies into the electricity system is the temporally fluctuating energy production by wind and solar power plants. Thus, in order to meet the ambitious long-term targets on CO2 emission reduction, long-term viable low-carbon options for balancing electricity will be needed. This interdisciplinary study analyses published future energy scenarios in order to get an impression of the required balancing capacities and shows which framework conditions should be modified to support their realisation. The authors combine their perspectives from energy engineering, technology assessment, political science, economical science and jurisprudence and address science, politics, actors in the energy sector and the interested public. Respectively, requirements for the balancing systems are analysed, considering the case of Germany as a large country with high ambitions to reduce greenhouse gas emissions. Additionally, an approach to investigate the optimal design of the technical system for balancing electricity over Europe is sketched. Looking at the challenges of a future energy system a mix of complementary technologies will prospectively become prevalent. In order to foster the needed innovation processes adequately, several funding mechanisms and legal regulations should be adapted. The authors give recommendations to handle major challenges in the development of the technical infrastructure, for the design of market conditions and for specific support of the application of balancing technologies.