The last years have brought a fundamental political change towards energy management in Germany: As soon as possible regenerative energies on all scales are to replace nuclear as well as fossil fuel energies. Electromobility is changing traffic profiles, in particular urban traffic. Decentralized compact power stations that save one portion of the inevitable thermodynamic degree of efficiency by consuming the heat at the generation site will have to be established and optimally linked. Apart from these individual topics, the overall topic of energy efficiency has gained a dominant importance. All of these topics induce numerous new quantitative problems of high complexity, which are the source of new mathematical challenges.Photovoltaics is one of the fastest growing regenerative energy sectors. In the focus of present interest are demands of higher efficiency with lower material usage and production costs.In the Action Plan for Electromobility 2020, Berlin sets the goal of becoming Europe's leading location for electromobility. As for the technological basis, the key words are fuel cells, novel batteries or plug-in hybrids. Of course, urban traffic will be the topic of main interest for Berlin.Decentralized power station networks. In the years to come, an increasing number of buildings will produce energy in a regenerative way, e.g., via solar cell roofs and walls. Whenever the produced electrical energy is not needed at the homes, the locally available electrical power will have to be fed into the communal electrical network systems. This gives rise to multiple problems of energy distribution and optimal network management, problems of utmost mathematical and computational complexity.