However Russia's troops probably rely on Ukrainian electricity in their temporary bases. Without it they have to bring even more fuel with them, especially in the winter, creating new logistic problems. On the other hand most of Ukraine's trains are electric, so moving war machinery and industrial supplies will become more difficult for Ukraine. Yet if Ukraine can't use the rails they will likely damage them to keep Russia from using them, which again will create logistic problems for Russia. Seems like both sides are harmed by cutting electricity. An obvious response will be to cut power to Crimea and other occupied territories as well.