Specialized climate indices for the energy sector in Ukraine based on the Euro-CORDEX projections

In Ukraine, the consequences of climate change are exacerbated by the military aggression of the Russian Federation (RF) not only in the temporarily occupied territories but also for the entire country, since all resources are primarily directed at strengthening defense capabilities and confronting the enemy. Nevertheless, climate change has not stopped and rather intensified in recent years. At the same time, due to the massive and targeted shelling of RF, almost all generating capacities at thermal power plants in Ukraine have been destroyed, the largest hydroelectric power plants have also been damaged and destroyed, and nuclear plants often cannot operate at full capacity, especially in the summer due to the heatwaves, when temperature in water cooling reservoirs increases significantly and the efficiency of nuclear power plants decreases. On the other hand, due to the same heatwaves, the demand for electricity increases significantly due to the need for air conditioning, which requires redistribution and other planning of electricity generation in the system. That is why Ukraine needs to solve problems simultaneously and plan development strategically, taking into account changed climatic conditions. Moreover, renovation of the country's infrastructure, in particular the energy and communal sectors, needs thorough consideration of the climate changes that are inevitable in the future.

To analyze climate change to date, the E-Obs database of the European ECA&D project was used, and to estimate future changes in indicators, data from 34 regional climate models of the International Coordinated Scaling Experiment for Europe (Euro-CORDEX) were used, which were calculated under two scenarios RCP 4.5 and RCP 8.5 until 2100 with a high resolution of 0.1^o.

We analyzed specialized indicators (Climatic Impact-Drivers – CIDs) for the energy sector as follows: heating period (in Ukraine with t<8^oC) duration, start and end dates; number of days per year which require the air conditioning (t>22^oC); mean temperatures of the heating and cooling periods and heating and cooling degree days (HDD and CDD); as well as the temperatures of the warmest and coldest 5-day periods to determine peak loads on the power system for 3 future periods (2021-2040, 2041-2060, and  2081-2100) vs 1991-2010.

In general by the end of the century, under the RCP 4.5 scenario in Ukraine, all analyzed CIDs may be the same as in the middle of the century under the RCP 8.5 scenario. As for degree days, their decrease in HDD does not compensate for the increase in CDD in the warm period for the high-concentration scenario. Moreover, the changes will occur in different regions differently with a significant decrease in the demand for thermal energy in winter in the north-eastern regions and a significant increase in costs during the air conditioning period in the southern and south-eastern regions with maximum values in the Autonomous Republic of Crimea.

The results obtained are the basis for the development of climate change adaptation strategies for almost all sectors of the economy and should become the basis for further assessment of risks and vulnerabilities of the energy and other economic sectors in Ukraine.