Energy expert warns: Dismantling coal-fired power plants jeopardizes the energy transition

By Prof. Dr. Clemens Hoffmann

A key aspect of the target picture is that power plants will always be a fundamental component of a renewable energy system. A common misconception is that the expansion of renewable energies will eventually make power plants superfluous. This misconception leads to a polarization in the political discourse between the proponents of renewable energies and the defenders of the existing energy system. However, this polarization hinders a proper transformation.

In order to achieve the goal, the power plant structure must develop in the following steps: in the first step, the existing power plants must be made more flexible in their mode of operation. The concept of "base load power plants" will no longer exist in the future system. Renewable energies are neither "base load capable", nor do the power plants operate at base load. A new term "balancing power plants" needs to be established. In the future system, electricity demand will be met by permanently and dynamically balancing the output of renewables and power plants. In a second step, the output of the power plants must be increased beyond today's level. This is because motor vehicles and heat generation will be increasingly electrified. The expansion of the electricity system to include these two energy sectors will lead to considerably greater flexibility potential, which is of great importance for the interaction with the power fluctuations of renewables. In Germany, the current power plant capacity of around 70 GW will have to be increased to around 110 GW. In the third step, the fuel of the power plants can be switched from coal to methane (natural gas). The fourth and final step is to switch from coal and gas to electrolytically produced hydrogen. However, due to the low efficiency of hydrogen production, this fuel switch only makes economic sense once the energy share of the power plants has been reduced to around 15%. It is therefore also a misconception that electrolytically produced hydrogen can be the main component of the target scenario. Realistically, it can be assumed that this residual demand from balancing power plants can be completely replaced by hydrogen in around 30 years. In the context of the transformation of power plants, hydrogen is therefore not the most urgent issue.

The timetable for this restructuring of power plants is therefore determined by the expansion of renewables and not vice versa. The predicates of the energy transition are "expansion" and "conversion", but not "dismantling". The energy transition is an "investment transition" with a highly attractive risk-return profile. The existing power plant structure represents a high economic value that must be cherished and maintained. The building shell, electrical generator and control center are valuable assets that must be preserved. The balancing power plants of the future will evolve from the existing power plants through further developments in burner and turbine technology. It would therefore be economically fatal to destroy a functioning power plant infrastructure now, only to rebuild it in 30 years' time at great expense.

About Clemens Hoffmann

Clemens Hoffmann is head of the Department of Integrated Energy Systems at the University of Kassel. His research interests include business models for the energy transition, the digitalization of the energy transition and smart grids. Until 2021, he was Head of the Fraunhofer Institute for Energy Economics and Energy System Technology (Fraunhofer IEE). Previously, he held senior positions at Siemens in the field of renewable energies and smart grids.