In the post-war reconstruction, the power sector, as a fundamental industry, will play a key role in the stable growth of the economy.

Decentralized generation from renewable energy sources (RES), located closer to consumers, is less vulnerable to aerial attacks.

Nearly 18 months of fierce resistance against the Russian invader have shown that the power sector is much more than just an economic industry; it is essential for survival in wartime conditions. This has led to a shift in the approach to energy, focusing on guaranteeing its security. The colossal destruction of infrastructure, which resulted in significant economic losses in Ukraine (according to the UN, in 2022, it decreased by 35%), and in its foundational industry of power generation, led to a global energy crisis. This crisis has already brought about substantial changes in the development of the energy sector, accelerating the development of green energy across all continents, especially in EU countries.

The European Union now understands that its future is only possible with energy independence from Russia. Energy security has become an additional strong motivation for speeding up the commissioning of facilities that produce electricity from renewable energy sources (RES). According to the International Energy Agency, in the next five years, RES will surpass coal and gas to become the largest source of electricity worldwide.

Unlike centralized energy systems, decentralized RES generation, located close to consumers, ensures local electricity supply to cities, communities, and large enterprises, and is less vulnerable to missile and aviation attacks. This decentralized generation could play a major role in the post-war rebuilding of our energy system, making it less vulnerable to conflicts. Therefore, decentralization of the energy system and the creation of backup capacities should ensure its high resilience.

It is worth noting the significant role of cooperation during the war with the European energy system ENTSO-E, which helped stabilize the unified energy system of Ukraine (UES) after massive destruction caused by missile strikes. The war with the Russian aggressor has shattered the global order, showing that for the aggressor, there are no rules or international obligations. For example, the terrorist act of blowing up the Kakhovka Hydroelectric Power Station (HPS), carried out by Russian occupiers at one of the largest reservoirs in Europe with a volume of 18.2 km³, led to the largest technological and environmental disaster of the 21st century, not only in Ukraine but also in Europe. The destruction of the Kakhovka HPS caused significant damage to our economy, resulted in severe consequences for industry, energy, agriculture, and the environment, and caused serious problems with water supply for the population in the southern part of the country.

In wartime conditions, when Russian occupiers damaged or destroyed 50% of the energy system (according to the government), captured the Zaporizhzhia Nuclear Power Plant and several thermal power plants, it was critical that hydropower plants (HPPs) and pumped-storage hydropower plants (PSHPPs) played a major role in stabilizing the UES, ensuring a significant share of electricity production to cover peak loads and regulating frequency and power in the UES.

During almost daily emergencies due to constant shelling and destruction of energy infrastructure, high maneuverability HPPs and PSHPPs provided the necessary additional capacities in the shortest possible time to balance the energy system. More than 500 days of war with the Russian invaders showed that hydropower remains the main fast-acting generation necessary for the UES, ensuring its survival in critical situations.

Equally important is the fact that during the war, it was the reservoirs of HPPs that ensured a constant water supply for industry, agriculture, and the domestic sector, as well as ecological water releases.

Renewable energy is not only a green transformation but also energy security and the stability of power supply.

In seeking ways to restore the country, it is essential to rethink the further development of our highly energy-consuming economy and its basic sector—power generation. We must focus our efforts and investors’ funds on the new realities, creating conditions for a rapid energy transition and industrial transformation.

Ukraine’s integration into the new EU strategy, the European Green Deal, the integration of Ukraine’s energy system with the European ENTSO-E, and the real prospects of our EU membership, with unprecedented financial, economic, and technological support from the EU, the USA, Canada, and other countries, create significant opportunities to make an innovative breakthrough and achieve ambitious goals, based on the latest technologies, to position ourselves as leaders globally and create a powerful economy on par with the developed European countries.

At the same time, it is important to consider the significant changes associated with the war with the Russian aggressor, which has led to the relocation of over a thousand enterprises from the eastern, northern, and southern regions to the western regions of the country. Hundreds of thousands of internally displaced persons have already found new homes and jobs here. Therefore, the accelerated development of the economy and the energy sector based on RES will take place here. Moreover, the integration of Ukraine’s energy system with the European system will create new conditions for its operation, improving reliability, and will play a key role in the stable growth of the industrial potential of western Ukraine. In the future, it will guarantee an increase in electricity exports.

Regarding renewable energy, it is not just a green transformation but also energy security and the stability of power supply, with decentralized, safer generation. An important point: according to a report from the Rocky Mountain Institute (RMI) from the USA, by 2030, wind and solar power will account for up to 33% of global electricity production, nearly tripling the share of RES, which currently stands at around 12%. European countries will significantly increase their RES production as well. According to the Ember analytical center, in 2022, wind and solar accounted for 22% of electricity production in Europe, and hydropower plants (HPPs) 7%. By 2030, they predict that RES production will increase to 45%.

Nuclear energy will remain the foundation of the UES, with a gradual reduction in the capacities of thermal power stations.

In the post-war reconstruction of the country, with changes in the structure of power generation capacities in the energy sector and the use of innovative technologies, nuclear energy will develop and remain the foundation of the UES, with a gradual reduction in thermal power stations and a rapid increase in RES, which will account for the main share of electricity production. The system will be regulated primarily by increasing the capacities of PSHPPs and HPPs, as well as the development of decentralized generation. Following the USA, the EU has classified nuclear energy as green generation alongside RES.

The war has shown the dangerous vulnerability of centralized systems. Therefore, in the new post-war conditions, it is important to ensure the transition to a decentralized, more flexible, distributed generation system in Ukraine, which is becoming an important development direction for both global and European energy. Additionally, the use of hybrid energy hubs, technologically combining wind and solar, hydropower, PSHPPs, industrial batteries, and hydrogen production, offers substantial technological and financial advantages and is gaining increasing development globally.

Such distributed generation, which operates on local grids and large individual consumers of electricity, will provide significant advantages for the more stable operation of the UES, improving primarily manageability, reducing transmission losses, increasing survivability and resilience of the UES in case of system-wide failures, and overall enhancing energy security. Decentralization is a matter of our security in the face of threats from Russia. Ukraine has large enterprises (metallurgical, mining, and beneficiation, etc.), cities, and communities that are planning local power supply based on RES.

According to Blombery New Energy Finance, distributed generation will take the main share of the energy market by 2040, with 40% of the world’s electricity to be produced from wind and solar power. For us, it is essential to consider another significant detail: according to Ukraine’s Ministry of Energy forecasts, by 2032, electricity demand in the country will exceed twice the demand before the full-scale war with the Russian invaders.

Thanks to the rapid increase in the capacities of wind and solar power, and the de-occupation of Zaporizhzhia region with the revival of the Zaporizhzhia NPP, Ukraine can cover the growing electricity demand, not only domestically but also largely for the EU, and become a hub for producing green electricity. It is worth noting that Ukraine’s Ministry of Energy plans to expand the transmission capacity of high-voltage power lines with EU countries, increasing their capacity from the current 1 million kW to 6 million kW by 2032 and 10 million kW by 2040, as some EU countries are forecasting an electricity shortage.

The war has shown the significant role of hydropower and pumped-storage hydropower plants in ensuring the stable operation of Ukraine’s UES and its survivability in critical situations. In our country, in the context of the energy transition, where RES development is prioritized, and given climate change with increasing extreme phenomena such as floods and droughts, the importance of hydropower is growing. It comprehensively addresses the issues of the economy, particularly in energy, water management, flood and drought protection, environmental issues, and more.

Like everywhere else in the world, our hydropower will continue to play a crucial role in balancing the UES, providing frequency and emergency reserves, and overall ensuring its stable operation in the future, with rapid growth in the capacities of solar and wind power stations and their intermittent electricity production. It is also important to consider another point: in Ukraine, where water resources are very limited, particularly in the south, the reservoirs of multipurpose HPPs are of vital importance for the economy. With a total annual river runoff of approximately 87 km³, only 52 km³ are formed on the territory of Ukraine, and in dry years, the annual runoff decreases to 30 km³. The volume of river runoff per capita is among the lowest in Europe.

Given the uneven distribution of river runoff across the country and seasonally, 1,090 reservoirs with a useful volume of 25.3 km³ have been created for its regulation and rational use. Rivers with reservoirs and very limited underground water resources are the main sources of water supply.

Thanks to the water resources of the Dnieper River with a cascade of HPP reservoirs with a useful volume of 18.4 km³, water supply is provided for the population, industry, agriculture, and irrigation in areas where nearly 70% of the population lives. Water from the Dnieper reservoirs is channeled to water-scarce areas such as Donbas, Kryvyi Rih, and the Azov region, irrigating more than a million hectares of arid land in the south of the country.

In recent decades, the years 2015, 2018, and 2019 were dry and low-water years. It was only thanks to the reservoirs that full water supply was ensured. The useful volume of the Dnieper cascade reservoirs is a strategic reserve of fresh water, ensuring that the population and the economy will be supplied with water in critical situations. Water supply is a matter of national security.

The destruction of the Kakhovka HPS with a capacity of 334 MW and a useful volume of 6.8 km³ reduced the total useful volume of the Dnieper cascade reservoirs by 37%, leading to severe consequences for the country’s economy.

Our institute, PJSC “UkrHydroProject,” together with the customer PJSC “UkrHydroEnergo,” is already working on a project to build temporary dams that will ensure the filling of the reservoir to a temporary mark of 12.7 m, allowing water intake for the Zaporizhzhia NPP and other water intakes, ensuring the further restoration of the HPS.

The operation of the Dnieper and Dniester cascade reservoirs has demonstrated their reliability in providing protection against catastrophic consequences, significantly reducing the risks of floods, and mitigating the damage to the environment, population, and economy.

In the Carpathian region, the country has the largest unused hydropower resources.

One of the reasons for this is that the issue of flood protection is complex. The authorities should not address it locally but rather in conjunction with water management and hydropower utilization of mountain rivers, as the Carpathian region possesses the largest unused hydropower resources in the country. Here are just a few figures: currently, these unique resources in Ukraine ensure an annual electricity output of all hydroelectric power plants (HPPs) averaging 11 billion kWh, with a total capacity of 4.8 million kW. Specifically, small HPPs (up to 10 MW) contribute only 0.1 million kW (2.1% of total capacity). In EU countries (such as Austria, France, Italy, Poland, and Switzerland), the capacity of small HPPs accounts for 8–20% of the total HPP capacity.

We have all the opportunities to improve these figures. Based on preliminary project developments and studies, the unused technical hydropower potential in Ukraine could amount to 4 billion kWh, including 1–1.5 billion kWh for small HPPs. Most of this potential is in the Carpathian region. For example, in the Lviv region, it was recommended to further explore prospective small hydroelectric power plants with a total capacity of 37 MW, generating 130 million kWh. The rational use of this vast potential requires, of course, well-balanced decisions considering environmental impacts as a key factor.

As global experience shows, among modern technologies for balancing electricity in the Integrated Power System (IPS), pumped storage power plants (PSPPs) are the most efficient and widespread worldwide (accounting for almost 94% of all regulating capacities). PSPPs have significant advantages in cost, capacity, and operational lifespan over industrial batteries. Therefore, where favorable natural conditions exist, PSPPs are primarily built.

Unlike conventional HPPs, PSPPs not only generate electricity but also consume its excess (for instance, the surplus generated by nuclear power plants at night or by wind and solar power plants throughout the day) by pumping water from the lower reservoir to the upper one. This process allows for regulating load schedules within a wide range.

Globally, PSPPs have a total capacity of approximately 170 million kW, with over 53 million kW in Europe alone (Germany – 5.7 million kW, France – 5.7 million kW, Italy – 4 million kW). In Ukraine, the current PSPP capacity is around 2 million kW.

In countries with favorable conditions, large-scale PSPP construction continues. According to the International Hydropower Association (IHA), their capacities are expected to double by 2030.

Ukraine has sites for new prospective medium (up to 350 MW) and large (500–1300 MW) PSPPs in the western, southwestern, central, northern, and Dnipro regional energy systems, with a preliminary total capacity exceeding 10 million kW. These PSPPs could significantly contribute to balancing Ukraine’s IPS amid the further development of renewable energy sources (RES). In the south, PSPPs are being considered with reservoirs utilizing depleted stone and mineral quarries.

Given the current electricity shortage in the country and the rapid growth of wind and solar power capacities, it is crucial to promptly introduce new high-maneuverability balancing capacities in PSPPs. First, it is necessary to complete the construction of the Dniester PSPP by commissioning its final units No. 5–7 and the Tashlyk PSPP with units No. 4–6, which will collectively provide 1.4 million kW, as per project specifications, and to initiate the construction of other PSPPs.

The mountainous terrain of the Carpathian region offers highly favorable conditions for PSPP construction. For example, in Lviv region, there are sites for the construction of medium high-head efficient PSPPs with a total capacity of nearly 2 million kW, which could ensure grid balancing along with further integration of wind and solar energy in the region.

An important aspect of PSPP construction is that investments remain in Ukraine, covering all necessary work, including technological equipment. This, considering the multiplier effect, will further stimulate economic growth, domestic industry, job creation, and socio-economic development of the regions.

Moreover, integrating Ukraine’s IPS with the European system and implementing a joint electricity market will provide a significant boost to the country’s economy and that of the western region. Under the current conditions caused by the war, this region has highly favorable circumstances for the rapid expansion of RES and PSPP construction. Ukraine could become a leading player in the European electricity market, significantly increasing exports of carbon-free electricity, particularly the most needed and valuable high-maneuverability balancing electricity from PSPPs and their ancillary services.

Doctor of Technical Sciences
Chief Advisor, PJSC “Ukrhydroproject”
Yuriy Landau