• Winter demand [for electricity in Ukraine] is 18 gigawatts, but Ukraine is currently able to generate only 12–13 gigawatts domestically. This leads to frequent outages. Ukrainian sources report that household electricity outages in 2024 totaled nearly 2,000 hours: In November, power was down 25 percent of the time, and in December that rose to nearly 40 percent. Ukraine can make up some of the deficit by importing electricity from neighboring E.U. countries. Under existing agreements, however, Ukraine cannot import enough to meet demand. Widespread residential blackouts are frequent across the country, even when power plants and the grid are not under immediate Russian attack.
• And supply seems constantly under threat: There have been over 1,000 attacks on Ukraine’s power grid since the start of the war, with Russia escalating its energy-focused attacks in 2024.  A new round of bombardments in August undermined the efforts of Ukrainian authorities to restore the power supply over the summer. By September, the grid was reportedly generating only one-third of its pre-February 2022 level. Due to the repeated bombings of thermal and hydropower plants, the majority of Ukraine’s remaining electricity generation now comes from nine nuclear power plants arranged in three complexes: Rivne (four reactors), South Ukraine (three reactors), and Khmelnitsky (two reactors). Russia has been reluctant to attack these facilities directly due to the risk of releasing radioactive contaminants into the surrounding environments.
  • Ukraine’s damaged electrical grid is 70 percent reliant on three complexes of nuclear reactors.
• Russia does not need to attack the three remaining nuclear power plant complexes to collapse Ukraine’s electricity supply. The national grid is connected by 103 substations, which used to integrate electricity from several sources (e.g., nuclear, coal, gas, and hydro) but now rely mostly on nuclear power. This lack of source diversity weakens the grid, increasing the chances of cascading failure.
• The substations are a vital part of the entire system. Without them, nuclear power plants can neither supply the grid nor retain the backup supply of power that is essential for reactor safety. Therefore, the loss of offsite power to a nuclear power plant is a serious problem. To make matters worse, many of Ukraine’s substations are exposed and vulnerable, lacking adequate protection against Russian air attacks.
• Forcing a shutdown of a nuclear power plant by attacking the surrounding substations is straight out of the Russian playbook: In September 2022, Russia compelled  the closure of the Zaporizhzhia Nuclear Power Plant using similar means. By attacking nearby substations and thereby frequently interrupting the steady flow of power across a period of several weeks, Russia drove the facility to decrease output, then to supply power only to itself, and finally to lose connection to offsite power. This loss of offsite power happened repeatedly during the attacks, raising the perceived risk of an accident enough that the International Atomic Energy Agency intervened, encouraging Ukraine to close the facility, which it did in September 2022.  Russia declared that it had taken control of the shuttered plant on Oct. 5, 2022. It remains in Russian hands today.
• From that experience, Russia learned how the International Atomic Energy Agency might respond to a situation of heightened danger to a nuclear power plant. In fact, the agency has played a leading role in helping Ukraine manage its nuclear power since the start of Russia’s full-scale invasion in February 2022. Thus, the prospect of using the agency as a tool to compel shutdown offers a potentially attractive option to the Kremlin.
  • Since Ukraine has submitted to heightened oversight by the International Atomic Energy Agency, the decision to shut down its nuclear plants if the perceived risk becomes too high may not be entirely its own.
• International advisors and Ukrainian energy experts agree that the best measure Ukraine can take to avoid grid collapse is to concentrate air defense systems on protecting the key substations: Defending the grid is as critical as defending the remaining megawatts. Even the International Energy Agency, which typically focuses on the infrastructure and market development of its members, has included “bolster the physical and cyber security of Ukraine’s critical energy infrastructure” first among its priority recommendations for getting Ukraine through the rest of the winter.
• If keeping Ukraine’s electrical grid functioning seemingly requires huge investment, consider the cost of a failure to do so. Ukraine’s ability to keep the lights on is closely tied to both regime survival and European stability. Ukraine is 70 percent urban, with five major cities having over 900,000 residents each. Large urban areas such as these rapidly become ungovernable without electricity. The highly centralized systems in Ukraine mean that a loss of electricity puts water, sewage, and heat at risk as well, increasing the likelihood of large-scale population displacement. An estimated 6.8 million refugees have already left Ukraine, with an additional 4.0 million internally displaced. A catastrophic outmigration would create a refugee crisis across Europe, especially in neighboring states.
• A grid collapse, should it occur, would reflect the ongoing role played by energy in this war. From the 2015 severing of Crimea from Ukraine’s electricity grid, to the 2015–2016 massive cyber attacks on Ukraine’s grid, to the destruction of the Nord Stream II pipeline, energy has factored heavily into the grievances and the ends, ways, and means of the Russo–Ukrainian war from its outset. We now find ourselves in a moment in which a slow war of attrition could come to an abrupt end, resolved by the triumph of cold and darkness. Ukraine’s survival now turns not on megatons, but on megawatts.
• Protecting the grid’s key substations is now the single most important priority for the survival of the Ukrainian state. By targeting electricity, Russia has made the current phase of the war an urban battle between darkness and light — and there is a clear scenario whereby darkness could triumph.

Read the full article at War on the Rocks.

Opinions expressed herein are solely those of the author. Photo by AP Photo/Evgeniy Maloletka.