Impacts of Climate Change
Water availability and heat
As a result of climate change it is expected that summer precipitation will decrease while winter precipitation will increase. Furthermore, more frequent heavy rainfall is expected, especially in winter. At the same time, the temperature will rise in Germany. These changes affect the availability of water in particular.
High temperatures and marginal rainfall may cause a lack of cooling water in thermal power plants, such as coal, natural gas and nuclear power plants. Cooling water is essential for the generation of electricity in thermal power plants if no other cooling systems, such as air-cooling devices are available. In most cases, the cooling water is taken from flowing waters into which warm water is subsequently fed into again.
Long heat waves limit the availability of cooling water. The water volume decreases because of low water levels and rivers warm up with rising air temperatures. Since warmer water has a lower cooling effect, larger amounts of water are needed to reach a cooling effect. In case safety-significant or water law thresholds are met, heated river water may not be used as cooling water. Also the reintroduction of cooling water into warmed up rivers is problematic in terms of the rivers’ ecosystems. For that reason, it is restricted by law. In extreme cases, thermal power plants have to be shut down.
Low water levels in rivers reduce the output of hydroelectric power plants. In addition, low water levels affect the inland waterway transport and thus impede the transportation of fuels such as coal for thermal power plants. This can lead to fuel supply shortages. Heat also affects the efficiency of air-cooling systems of thermal power plants and gas turbines. High summer temperatures can limit the energy production as well as the energy distribution by causing damage to underground cables and transmission losses in overhead lines. During long periods of heat, all these factors can lead to an energy supply shortage. In this respect, conventional energy supply is particularly vulnerable due to its centralised power generation in large power plants. The failure of one or more of these systems can significantly affect the power supply.
Yet climate change can also increase the water level and the flow force temporarily. In mild winters when precipitation is not stored as snow but flows off as rain water instead, the greater flow rate can increase the output of hydroelectric power plants.
Extreme weather events
Climate change can have an impact on the frequency and intensity of extreme weather events. These include floods, heavy rainfall, storms, hail and thunderstorms. Already a single extreme weather event can cause huge damage to the energy infrastructure. Storms and lightning strikes, but also large snow masses (as in Münster in 2005) can damage energy conversion plants and power lines. This can endanger the electricity transmission and distribution. Since the 1970s, supply failures have increased. Increasing temperature decrease the efficiency of photovoltaic modules, which can also be damaged by hail or storm. During severe storms it can be necessary to turn off wind turbines. Furthermore, severe storms can affect the accessibility of offshore wind power plants and damage on- and offshore wind turbines. However, during long-lasting lulls, for example under stable high pressure weather conditions, wind turbines cannot produce electricity. Furthermore, snow layers affect the productivity of photovoltaic systems.
In addition, heavy rainfall and floods affect the operation of raw material and fuel production plants, for example, oil, gas, coal and lignite production facilities. At the same time, floods restrict the inland waterway transport of fuels and the transport on railway lines and roads that run parallel to the rivers. As a result, thermal power plants may suffer from a lack of fuel supply. Floods can also threaten power plants through flooding, including containments, and suspension of plants. High water levels can also affect the electricity production of hydroelectric power plants if the necessary drop height at barrages is reduced. Floods also pose a potential risk to transformer stations, substations and other network components: cable lines can be flushed out, poles can be damaged or water can undermine pole foundations. Floods can also have an impact on the gas and district heating network, for example by flooding transformer stations or gas pressure control systems. Apart from affecting the public energy supply, floods can also impair energy conversion and heating systems in private households. They can cause damage to boilers or power lines. Flooding of electrical components of photovoltaic systems can cause short circuits and thus damage the modules.
Floods can also significantly damage biomass production areas (see also Climate impacts in forestry and agriculture). Heat, droughts, hail and heavy rainfall are other weather conditions that are capable of affecting their output. Potential results are supply shortages and increased energy prices.
As a result of higher temperatures, the cooling demand of households and production facilities increases. Also the transport and storage of goods can increase the cooling requirements. The resulting increased electricity demand can lead to supply shortages, especially during periods of reduced production possibilities, for example during long periods of hot weather. Warmer winters, however, can reduce heating requirements.
- The German Federal Government (2009): Combating Climate Change. The German Adaptation Strategy
- UBA (2011): Themenblatt: Anpassung an den Klimawandel - Energiewirtschaft
Adaptation to Climate Change
Due to the fact that conventional energy supply has so far been dominated by centralised electricity supply provided by large power plants, it is particularly vulnerable to failures of individual power plants. Restructuring the energy supply with a focus on renewable energy sources, especially wind energy and photovoltaics, also entails a greater decentralisation of the energy supply, which is thus more resilient to individual failures and locally limited events.
A central problem for the conventional energy conversion under a changing climate is the supply of thermal power plants with cooling water. Renewable energies can reduce the demand for fossil-generated (peak) load during summer months that are problematic in terms of cooling water supply. In addition, thermal power plants should be equipped with innovative cooling concepts, such as combinations of wet and dry cooling systems. Due to their significantly higher fuel efficiency and their thus better production efficiency, facilities that operate with combined heat and power or with combined heat and power and cooling processes can also reduce their cooling water requirements. However, this is subject to the availability of suitable heat or cooling energy customers.
Another climate change-induced challenge for power plants is the increased risk of inundations due to heavy rain and floods. Although high safety standards already apply to power plants and endangered sites are equipped with flood protection systems, they can be impaired or even have to be switched off in individual cases, as occurred in Gera Süd in 2013. Already today, drainage systems are expanded as part of adaptation measures in central power plants. However, especially buildings outside of the actual plant areas are subject to flooding risks. Thus it is important to find suitable sites when constructing new buildings.
Especially conventional power plant operators may encounter logistical needs for adaptation. If the use of waterways for the transport of fuels for conventional power plants is restricted or interrupted due to high or low water, alternative supply and transport routes should be available. A more flexible approach to transport and logistics concepts as well as the development and new construction of local storage facilities are ways to adapt effectively.
Of course also renewable energies can be affected by the consequences of climate change: Since the feed-in of electricity from those renewable energies that will have the greatest significance in the future energy system (wind energy and photovoltaics) is subject to weather conditions, storms, calms, snow and hail are already relevant today. For that reason, several concepts and technologies, such as storm limitations in wind turbines that can respond to extreme weather events have already been developed. In the field of wind turbines, logistics, access and maintenance concepts are optimised, too. These measures also include remote maintenance systems for offshore wind turbines. Photovoltaic systems in flood-prone areas should have a switch for a controlled short circuit in order to prevent short circuits if electrical components are flooded. Hail damage can be reduced with the help of thicker protective glass for photovoltaic modules.
Electricity transmission and network security
Possible extreme weather events such as floods, storms and thunderstorms, which can cause damage to the networks, should be considered when determining the position of network elements such as overhead power lines and transformer stations. Both great snow loads as well as an overload of networks in case of extreme temperatures can be prevented with the help of technical measures: In addition to an overhead line monitoring, or a temperature monitoring, respectively, high temperature conductors can reduce the risk of excessive transmission capacity. Heating wires or PEDT (pulse electro-thermal de-icing) can heat pipes in order to provide protection against freezing.
Higher temperatures increase the cooling demand, especially during summer months. Therefore, energy saving measures that reduce the demand are necessary. This needs to be taken into account especially in building designs and urban planning processes. For example, building insulation or shading devices can reduce cooling requirements significantly. In addition, the energy efficiency of technical devices can be increased.
Political, legal and management measures
The energy demand can also be influenced through management measures, such as electricity consumption monitoring and supply-oriented prices. Very sunny and windy weather conditions can cause an overload of the networks. The so-called feed-in management ensures that individual power plants reduce their performance in case of network congestion. Pursuant to the Renewable Energy Sources Act, only facilities equipped with such power reduction devices shall be promoted.
Further research will result in findings on other possible management and technical adaptation measures. This is necessary in order to create a reliable information base for planning and investment processes and for the development of innovative adaptation technologies. Thus, further information concerning relevant climate changes such as the development of water temperatures or runoff amounts are required.
In order to successfully deal with extreme weather events, active risk management of energy companies is required. It is important to set up emergency plans at an early stage as well as raise awareness and provide training courses for staff members. In that regard, also the formation of crisis management teams can ensure that the required actions are taken quickly.
In general it is therefore important to raise awareness of climate change-induced changes and challenges within the energy sector and to link the relevant stakeholders. In the Working Group “Crisis precautions in the Electricity Industry” established by the Federal Ministry for Economic Affairs and Energy (BMWi), the federal government and state governments as well as energy sector representatives discuss different crisis scenarios for extreme weather events and possible measures under the provisions of the Energy Industry Act and the Energy Security Act.
Furthermore, the state has the opportunity to create incentives to preserve the functioning and the development of infrastructure in the energy sector. For example, new storage technologies are explored as part of the “Funding Initiative Energy Storage Systems” of the federal government.
If you are interested in obtaining information about concrete impacts of climate change in the field of action energy sector, please click here.
- The German Federal Government (2009): Combating Climate Change. The German Adaptation Strategy
- The German Federal Government (2008): German Strategy for Adaptation to Climate Change
- UBA (2011): Anpassung an den Klimawandel - Themenblatt Energiewirtschaft
- UBA (2011): Stakeholder-Dialoge, Chancen und Risiken des Klimawandels, 03/2011
- UBA (2011): Ökonomische Aspekte der Anpassung an den Klimawandel. Literaturauswertung zu Kosten und Nutzen von Anpassungsmaßnahmen an den Klimawandel, 19/2011