Our economy and society are fundamentally dependent on energy – and electricity is the crème-de-la-crème of our current energy sources. Without electricity, the likes of communication technologies, many household appliances, lighting, most engines, and even most industrial production would be unthinkable. Even in the heat and transportation sectors, it may in the future make sense to replace oil and gas with renewable electricity. Electricity thus plays a critical role in the ongoing restructuring of Germany’s energy supply.
In order to hit Energiewende and climate-protection targets, a shift of power generation to renewable energy sources is elementary. In the meantime however, over a transition period, renewables (above all wind and solar) as well as existing conventional power (coal, gas, oil, and nuclear power until 2022) are going coexist. Renewable energies currently take precedence over conventional power in Germany’s power supply; this is not only stipulated in German law, it is because with their low operating costs, they undercut fossil fuels on the marketplace.
That’s why conventional power plants are taking on a new role in Germany: They’re being used during the transition as back-up capacity. They jump in for renewables when the sun isn’t shining and the wind isn’t blowing and they balance the fluctuating residual load.
In Germany’s previous power system, conventional power plants did more than just fed electricity into the grid for purposes of end-user consumption. Indeed, conventional power plants also provided ancillary services for maintaining the power grid. For example, they supplied reactive (or idle) power, balancing energy, and so-called spinning reserves.
Renewable energy can also contribute to these ancillary tasks. In fact, today this is already the case, in part, through various schemes such as grid connection procedures, and special ordinance for wind power plants. In the future, renewable energy will shoulder the brunt of the power production in Germany, and thus also the aforementioned system services, either through renewable energy production itself or by other means, such as condensers. Also, the requirements for the production of electricity from renewable energy sources will have to change. The existing remuneration scheme for renewable energy, the Renewable Energy Sources Act (EEG) sets incentives in order to maximize the yield of clean energy generation. Following the successful and rapid expansion of renewable energies since 2000, the framework should now be further developed so that the costs of the whole energy system are minimized. This also means that compensatory measures (such as back-up power plants, load management, and storage) remain affordable.