Editing IPCC:AR6/WGII/Chapter-13 (section)

==== 13.6.1.1 Energy Systems ====

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The energy sector in Europe already faces impacts from climate extremes ( ''high confidence'' ). Significant reductions and interruptions of power supply have been observed during exceptionally dry and/or hot years of the recent 20-year period, for example, in France, Germany, Switzerland and the UK during the extremely hot summer of 2018 which led to water-cooling constraints on power plants ( [[#van%20Vliet--2016b|van Vliet et al., 2016b]] ; [[#Abi-Samra--2017|Abi-Samra, 2017]] ; [[#Vogel--2019|Vogel et al., 2019]] ). Heating-degree days decreased and cooling-degree days increased during 1951–2014, with clearer trends after 1980 ( [[#De%20Rosa--2015|De Rosa et al., 2015]] ; [[#Spinoni--2015|Spinoni et al., 2015]] ; [[#EEA--2017a|EEA, 2017a]] ). Projected climate risks for energy supply are summarised in Figure 13.16.

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[[File:56ddd582c5484ea2bbb2b06db3552dd2 IPCC_AR6_WGII_Figure_13_016.png]]

'''Figure 13.16 |''' '''Projected climate-change risks for energy supply in Europe for major sources and under 1''' '''.''' '''5°C, 2°C and &gt;3°C GWL (Tables SM13.5–13.13)'''

New studies reinforce the findings of AR5 on risks for thermoelectric power and regional differences between NEU and SEU regarding risks for hydropower (Figure 13.16). In NEU and EEU, extremely high water inflows to dams are projected to increase flooding risks for plant and nearby settlements ( [[#Chernet%20Haregewoin--2014|Chernet Haregewoin et al., 2014]] ; [[#Porfiriev--2017|Porfiriev et al., 2017]] ), while increasing temperatures could reduce the efficiency of steam and gas turbines ( [[#Porfiriev--2017|Porfiriev et al., 2017]] ; [[#Cronin--2018|Cronin et al., 2018]] ; [[#Klimenko--2018a|Klimenko et al., 2018a]] ). Water scarcity may limit onshore carbon capture and storage in some regions ( [[#Byers--2016|Byers et al., 2016]] ; [[#Murrant--2017|Murrant et al., 2017]] ; [[#EEA--2019a|EEA, 2019a]] ).

Reduced surface wind speeds during 1979–2016 ( [[#Frolov--2014|Frolov et al., 2014]] ; [[#Perevedentsev--2014|Perevedentsev and Aukhadeev, 2014]] ; [[#Tian--2019|Tian et al., 2019]] ) support projected trends in decreasing onshore wind energy potential. Seasonal changes may result in reductions in many areas in summer (by 8–30% in Southern Europe) and increases in most of NEU during winter. Increasing probabilities and persistence of high winds over the Aegean and Baltic seas ( [[#Weber--2018a|Weber et al., 2018a]] ) could create new opportunities for offshore wind. The future configuration of the wind fleet will affect the spatial and temporal variability of wind power production ( [[#Tobin--2016|Tobin et al., 2016]] ). Total backup energy needs in Europe could increase by 4–7% by 2100 ( [[#Wohland--2017|Wohland et al., 2017]] ) with potentially larger seasonal changes ( [[#Weber--2018b|Weber et al., 2018b]] ).

There is ''low evidence'' and ''limited agreement'' on projections of solar power potential due to differences in the integration of aerosols and the estimated cloud cover between climate models ( [[#Bartok--2017|Bartok et al., 2017]] ; [[#Boé--2020|Boé et al., 2020]] ; [[#Gutiérrez--2020|Gutiérrez et al., 2020]] ). Studies on climate risks for bioenergy are also limited.

Energy demand is projected to display regional differences in response to warming beyond 2°C GWL, with a the significant southwest-to-northeast decrease of heating-degree days by 2100 (particularly in northern Scandinavia and Russia), and a smaller north-to-south increase of cooling-degree days ( [[#Porfiriev--2017|Porfiriev et al., 2017]] ; [[#Spinoni--2018|Spinoni et al., 2018]] ; [[#Coppola--2021|Coppola et al., 2021]] ). Under the present population numbers, total energy demand would decrease in almost all of Europe, whereas it could increase in some countries (e.g., UK, Spain, Norway) when considering Eurostat’s population projections ( [[#Klimenko--2018b|Klimenko et al., 2018b]] ; [[#Spinoni--2018|Spinoni et al., 2018]] ). There is ''medium confidence'' that peak load will increase in SEU and decrease in NEU ( [[#Damm--2017|Damm et al., 2017]] ; [[#Wenz--2017|Wenz et al., 2017]] ; [[#Bird--2019|Bird et al., 2019]] ). Beyond 2°C GWL, a shift of peak load from winter to summer in many countries is possible ( [[#Wenz--2017|Wenz et al., 2017]] ). Together with water-cooling constraints for thermal power, this change in load may challenge the stability of electricity networks during heatwaves ( [[#EEA--2019a|EEA, 2019a]] ). Technological factors, increased electricity use and adaptation influence significantly the temperature sensitivity of electricity demand and consequently risks ( [[#Damm--2017|Damm et al., 2017]] ; [[#Wenz--2017|Wenz et al., 2017]] ; [[#Cassarino--2018|Cassarino et al., 2018]] ; [[#Figueiredo--2020|Figueiredo et al., 2020]] ). Potential power curtailments or outages during climatic extremes may increase electricity prices ( [[#Pechan--2014|Pechan and Eisenack, 2014]] ; [[#Steinhäuser--2020|Steinhäuser and Eisenack, 2020]] ).

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