Key findings

As Ukraine enters its fifth winter since Russia’s full-scale invasion, the country has worked to strengthen resilience, invest in passive protection measures for critical energy infrastructure and expand distributed energy resources, but the threat has grown faster. Russia’s drone technology and attack patterns have also continued to evolve, presenting an ever-growing threat to Ukraine’s energy system at a time when interception rates have declined. Ukraine’s system is better equipped than it was going into last winter, but more advanced jet-powered drones have already begun to erode the summer’s repair efforts. Air defence remains essential for maintaining the energy system.

Last winter confirmed the value of electricity imports and decentralisation, but neither was used to its full potential. Imports from Europe and decentralised supply have been two of Ukraine’s main strategies to keep the lights on since the full-scale invasion. Imports covered a growing share of the deficit, and local cogeneration and boiler houses kept heat and water running, where they were deployed. Yet, connecting delivered equipment has often taken months, and few local generation units or batteries can operate in island mode when the grid is cut.

Since last winter, Ukraine has added around 0.4 GW of distributed gas-fired generation and more battery storage, and set up a strategic reserve of energy equipment, while its repair crews have gained another winter of experience. Repairs, however, remain constrained by a shortage of replacement equipment. Meanwhile, Ukraine's gas storage is at a six-year high going into the winter, despite repeated attacks on production.

Ukraine has learned from the past four winters, but significant risks remain:

• Russia has begun using faster, jet-powered drone models that have already weakened generation, networks, gas and fuel supply before the heating season.

• Large-scale attacks on industry over the summer have lowered Ukraine’s electricity demand but they are also reducing the flexibility of the system to manage winter peaks. Industrial load was the first to be curtailed in shortages. A cold spell or damage to district heating could push evening peaks up again.

• Power shortages are likely this winter, and their depth will depend on attacks and weather patterns. Imports from Europe remain vital, but the import limit of 2 450 MW for the Ukraine-Moldova block cannot close the gap. Internal bottlenecks leave the eastern regions most exposed.

The measures most likely to make a difference this winter rely on assets already in Ukraine. Connecting delivered equipment adds capacity within weeks. Letting batteries and consumers reduce the evening peak relieves pressure during the scarcest hours. Keeping district heating running prevents households from turning to electric heaters and aggravating the electricity gap. Co-ordination between cities lets crews and reserves move to where an attack hits.

Equipment for winter 2027-2028 must be secured now. Critical equipment such as small cogeneration units and substation equipment takes six to nine months to deliver. Pooled procurement and the establishment of pan-European strategic stocks of equipment and spare parts could shift preparation from reactive to proactive ahead of next winter.