Cluster Energy industry | Umweltbundesamt

On the relevance of the action field

A secure, affordable energy supply, compatible with environment and climate requirements, is of elementary importance for Germany’s economy and society. The energy turnaround aims at converting our energy systems and ensuring the permanent supply of energy in a way that meets these requirements, by employing renewable energies and by using energy sparingly and more efficiently. In order to achieve the energy turnaround, a decision was made to end the use of fossil and nuclear sources of energy: The withdrawal from the nuclear energy programme was achieved in 2023, and by 2038 the generation of electricity and heat from the use of coal will be terminated. The conversion of the energy system requires far-reaching structural and infra-structural adaptations in all areas of the energy industry. This includes the expansion of transmission and distribution networks, the conversion of electricity, heat and cold supply systems into renewable energy sources, and making the energy system more flexible. Russia’s war of aggression against the Ukraine has made it necessary to take additional actions in order to secure energy supplies.

The priority use of renewable energy has led to an increase in the stock of plant and equipment which are exposed to the weather, weather patterns and consequently to changing climatic conditions. When planning and implementing the requisite measures, it is essential to take climate-related changes into account, in order to avoid – also with a view to the long-term return on investments – any negative impacts and the potential costs of adaptations required at a later date.

DAS Monitoring –what is happening due to climate change

Extreme weather conditions, that are expected to increase with climate change, are apt to confront the energy supply with challenges. This includes hot periods, as witnessed, for example in 2018 and 2022, when in Germany and other member states of the trans-European electricity network, the power generation in nuclear and coal-fired power stations was in some cases massively restricted. Owing to the high temperature of water sources, a two-fold problem occurred: on one hand there was not sufficient coolant water available, and on the other, coal supplies were restricted by low levels prevailing in waterways used by inland shipping. A renewable energy supply system brings about a distinct reduction in water-dependent risks. On the contrary, hydropower stations can indeed be affected as a user of renewable energy: their generation output decreased markedly for instance in 2018 and 2022 owing to drought.

Overall, Germany’s electrical energy supply is very secure. However, extreme events such as hot periods, storms, tempests with lightning and heavy rain, which are all becoming more likely in the course of climate change, are apt to lead to interruptions in the power supply. The indicator for weather-related unavailability of power supply illustrates the cumulative duration of weather-related interruptions to the supply. The hitherto highest value was recorded in July 2021, which was primarily a result of impacts from the ‘Bernd’ low-pressure system; this value amounted to an average of just under 23 minutes per end consumer within the meaning of the Federal Law on the Energy Industry (EnWG) (cf. Indicator EW-I-2). However, ‘Bernd’ did not have a marked impact on the frequency of weather-related disruptions as compared to the total of unscheduled disruptions recorded in that year (cf. Indicator EW-I-1).

Future climate risks – outcomes of KWRA

In respect of the DAS action field ‘Energy industry’ the 2021 Climate Impact and Risk Analysis (KWRA) found that, both for individual climate impacts and overall, the climate risk identified is low. For the assessment it is essential to take into account, amongst other factors, the withdrawal from nuclear energy in the run-up to 2023 and, according to current expectations, from coal by 2038. The conversion to renewable energies makes the power and heat supply in general less dependent – both quantitatively and qualitative – on the availability of sufficient water for cooling purposes or in terms of the transportation of primary energy sources.

In this context, energy demand is seen in terms of the essential climate-change related change in the demand for coolant energy. Apart from climatic impacts it is factors such as building stock and consumption behaviour which determine the amount of energy demand. Any concrete statements regarding the future coolant energy demand are therefore subject to major uncertainty. However, it is assumed that owing to the small amount of coolant energy as a proportion of the overall energy demand, it is not expected that there will be any power deficits. The 2021 KWRA did not identify any urgent requirements for action in respect of the climate impacts analysed.

Where do we have gaps in data and knowledge?

Implementing the energy turnaround involves the complete conversion of the energy supply system to renewable energies. In addition, the demand for electrical energy will increase significantly in order to replace fossil energy sources in various applications. For example, it is intended that increasingly electric heat pumps will be used for generating heat. As far a vehicular mobility is concerned, fossil-fuelled vehicles with internal combustion engines are to be replaced by electric vehicles. The reliability of electricity generation from renewable energies and any flexibilisation options available in the system will therefore acquire ever-more relevance.

There are uncertainties as far as any potential impacts of climate change on electricity generation are concerned, in particular with regard to the revenue situation. According to the findings of the 2021 KWRA it is understood that as before, strong wind events will in the future hardly ever lead to power supply disruptions owing to wind turbines. However, so far it has not been possible to make any sufficiently reliable statements in respect of wind energy in general, given that any projections regarding future wind speeds are subject to major uncertainty. Principally, it is assumed that wind scenarios will change only to a limited extent.¹⁵³ Nevertheless, a more precise presentation of wind projections would be desirable in future – especially at the turbines’ hub height – in order to have a better chance of estimating the impacts of climate change.¹⁵⁴ It remains to be examined to what extent it would be possible to obtain more specific projections with the aid of other meteorological measuring systems such as wind measurements recorded at wind turbines. Hydropower makes only a minor contribution to the renewable energies mix. In drought years such as 2018 and 2022 power generation from hydropower is sometimes severely restricted. Likewise, restrictions in the production of biomass are conceivable.¹⁵⁵ A more precise estimate of any relevant climate-change impacts would be helpful. In an energy system based on renewable energies, the market-related supply security can be affected, especially during long phases of cold dark doldrums, when a wintry weather scenario is accompanied by a lack of wind and solar energy. To date no research findings have come to light regarding the influence of climate change on the frequency and duration of dark doldrums. A data-based monitoring of dark doldrums would be desirable.

The resilience of renewable energy systems is closely bound up with their flexibility. Storage power stations and battery storage plant can provide flexibilisation options just as much as the generation of hydrogen or other energy sources emanating from surplus renewable electricity. Likewise, flexibly disconnectable or controllable consumption sites are included in these options. The further expansion of electricity networks and the trans-European electricity network play a relevant role in balancing electricity supply and demand at a large scale and in making it possible to buffer frequency fluctuations. In critical weather scenarios, meteorological data can help to indicate large-scale balancing opportunities.¹⁵⁶ Flexibilisation options support the resilience of the electricity system by protecting it from disruptions including meteorological extremes. In this context, the diversification of precautionary measures is of great importance as it enables the system or systems to react adequately to a variety of different situations. For the future it would be desirable to have a comprehensive monitoring system in respect of the actual utilisation of flexibilisation options thus illustrating the system’s responsiveness. However, this would first require some methodical deliberations.

What’s being done – some examples

In view of the challenges posed by the energy turnaround, climate adaptation – as a factor in further enhancing the energy supply system – tends to recede into the background. Nevertheless, the transformation process leads to a situation in which the climate risks involved in a largely fossil-based or nuclear energy supply for Germany will diminish in future – as shown with regard to coolant and low-water level issues – and measures are taken which increase the general resilience of the energy supply system. Part of the energy turnaround is for instance the expansion of the flexibilisation options mentioned above, for example by expanding battery and other storage capacities or by means of hydrogen production from surplus electrical energy. Such measures increase the resilience of electricity supply systems vis-a-vis fluctuations in electricity supply and demand as these are bound to increase owing to the intrinsic sensitivity of renewable energies to weather events. Likewise, the energy demand is also a focus of the energy turnaround. In a renewable energy supply system, reduced energy demand and increased energy efficiency can help to make it easier to safeguard the balance between energy conversion and application. In a similar way this is also true when changing climate conditions require reinforced balancing of electricity demand and supply.

^{153 - Füssel H.-M. 2019: Adaptation challenges and opportunities for the European energy system. Building a climate-resilient low-carbon energy system. EEA report, Band 01/2019. Luxemburg, 117 pp. doi: 10.2800/227321}

^{154 - Bär F., Kaspar F. 2023: Meteorologischer Jahresrückblick energierelevanter Wetterelemente für das Jahr 2022. Deutscher Wetterdienst, BMDV-Expertennetzwerk. 14 S. https://www.bmdv-expertennetzwerk.bund.de/DE/Publikationen/Pressemitteilungen/DWD_Baer_Kaspar_2022.html.}

^{155 - Drücke J., Borsche M., James P., Kaspar F., Pfeifroth U., Ahrens B., Trentmann J. 2021: Climatological analysis of solar and wind energy in Germany using the Grosswetterlagen classification. Renewable Energy, 164: 1254-1266. doi: 10.1016/j.renene.2020.10.102.}

^{156 - Drücke et al. 2021, cf. endnote no. 155.}