Ensuring Secure Power Supplies by Increased Utilization of Fossil and Renewable Energies
In 2010, nuclear power plants still supplied about 22 percent of Germany's electricity requirements. Whether Germany can do without this energy source, whether the associated costs are justifiable and how the avoidance of CO2 emissions will affect the environment is still being debated. So far, the switch-off of eight nuclear power plants has not caused any shortages. It must, however, be taken into account that Germany currently imports 2000 MW of electricity from French nuclear power stations every day.
Voith estimates that the eventual exit from nuclear power in 2022 will necessitate a whole package of inevitable measures, in order to ensure adequate energy supplies: these measures range from power savings and improved energy efficiency to grid extensions and the increased recourse to other energy sources. Regarding the latter, Germany will probably not be able to do without the development of fossil power plants until further notice. The intensified utilization of coal-fired power station naturally implies higher CO2 emissions, while gas power stations would increase Germany's dependence on Eastern European gas imports.
At present, renewable energies provide about 18 percent of Germany's energy requirements. In the long term, so the latest legislation, they are to dominate within the German energy mix. So far, the development of renewable energies has concentrated on wind power and photovoltaics. Yet larger plants have already become quite controversial. Residents protest against disfigured landscapes and noise.
In order to achieve the ambitious goals of the German government, it will be unavoidable to take recourse to all kinds of renewable energy. Here, hydro power has so far been the only source of renewable energy with a baseload capacity. This is the scope on which the research, development and installation of new renewable energies should be promoted. Voith is, for example, a pioneer in the segment ocean energies. The generation of power from waves or tidal currents is technically demanding but ultimately rewarding: According to the European Ocean Energy Association, ocean energy plants in Europe might generate an output of 188 GW by 2050. Harnessing ocean energy is also climate-friendly: the European Ocean Energy Association (EU-OEA) argues, that the utilization of ocean energy will lead to some 2.6 Mt less of CO2 by 2020, and by 2050 to as much as 140 Mt CO2.
Whatever the speculations, the implementation of the German energy transition will definitely call for comprehensive public and private investment. Assessments made on behalf the German Ministry for the Environment estimate that the replacement of nuclear power will cost about EUR 200 billion.
Securing Grid Stability by Developing (Pumped) Storage Capacities
Along with the energy transition, securing the grid stability has also become a challenge. Baseload requirements used to be served by fossil or nuclear power plants, which supplied continuous outputs. Within the scope of the energy transition, wind power and photovoltaic plants are now to replace these continuous power feeders. Consequently, the supply of power will become difficult to predict and impossible to govern. There is already an imbalance between power availability and demand: on a sunny, windy day, German wind and solar power plants produce more electricity than used up during the 'lunch time peak.' This is why pumped storage power plants pump water to the surface at times where they would normally generate electricity, in order to absorb peak loads. Therefore, the grid is already subject to fluctuations strong enough for the Federal Network Agency having to intervene 300 times per week. In the past, such interventions were only required three times a week on average.
This means that (pumped) storage capacity is an absolute must for integrating renewable energies in the grid. Compared with other energy storage methods, pumped storage power stations simply provide the better arguments: they are highly productive, can be flexibly controlled and reach high efficiencies. As we say at Voith: no wind without water!
