In his study „Energiewende und Versorgungssicherheit – Dunkelflauten erfordern Handeln!“, Prof. Dr. Markus J. Löffler from the Westphalian Energy Institute (WEI) at the Westphalian University of Applied Sciences sheds light on the problem of fluctuations in renewable energy sources and the challenges they pose for security of supply. If there is no fundamental change of course in energy policy, there is a possibility that the planned power plant capacities will no longer be sufficient, the study concludes. Background: By 2045, the entire electricity demand in Germany is to be covered by renewable energies.
Markus Löffler, an expert in high-voltage technology, advises using the capacities of controllable power plants in order to optimise periods of oversupply and undersupply where possible.
„If we continue on the current course with the existing gaps in power plant capacities, we will be in the dark again and again in just a few years“, said Löffler. „As outlined in the position paper by the Westphalian Energy Institute, Germany is jeopardising its economic competitiveness and social peace with this strategy. Renewable energies may not be the panacea for an energy transition that secures supplies.“
Growing risk of blackouts: energy production from renewables fluctuates
Due to fluctuations caused by the weather and time of day, renewables do not produce a constant amount of energy, which can lead to oversupply and undersupply situations – and ultimately to permanent blackouts, explains Löffler.
Within a 6-year interval, the simultaneous occurrence of darkness with power deficits of over 150 GW and wind lulls lasting between 1 hour and 11 days is very likely.
Offsetting longer-lasting electricity deficits with battery storage and pumped storage power plants
According to Löffler, battery storage and pumped storage power plants could provide a remedy. These could easily compensate for these „short-term small deficits of up to six hours“, and this would also be possible for up to 18 hours under certain circumstances.
„To compensate for longer deficits of up to eleven days, we would need controllable gas or hydrogen power plants in Germany with at least 150 GW of available capacity. Only 10 GW of hydrogen power plants are currently planned by 2035, with 35 GW of gas-fired power plants currently available. Or, if necessary, we would have to resort to electricity imports, as the existing battery storage systems and similar technologies would not be sufficient“, the energy expert continued.
In the event of an electricity shortage, there is no alternative to providing reliable energy sources that are available at short notice.
Controllable power plants only economical in continuous operation
However, the use of controllable power plants – especially those with a hydrogen supply of currently unknown origin - with an average of 500 full-load hours per year is not economical and therefore unprofitable. Due to the sporadic utilisation, the production costs amount to up to 730 euros per megawatt hour of electrical energy. Only continuous operation would therefore make sense.
In order to counteract high electricity surpluses caused by the expansion of renewable energies, Löffler advocates the simultaneous use of controllable energy sources. It would be difficult for local hydrogen production: this would then be impossible, which would inevitably lead to imports.
Fundamental reorientation essential for the success of the energy transition
Prof Löffler concludes that security of supply can only be guaranteed by using „reliable, controllable power plants“ and calls for a reorientation in terms of a sustainable and secure power supply.
He considers the energy transition in its current form to be a failure – not least due to the major weaknesses of current planning and realisation processes.
Click here for the full study:
https://www.w-hs.de/fileadmin/Oeffentlich/WH-Institute/Westfaelisches-Energieins
