I wouldn't say that. Those generators are quite expensive to run. Businesses turn them off whenever grid power is available, which at the moment is 100% of the time (in late August and early Sept Russia spent ~$1 billion on missiles and drones attacking energy infrastructure, but Ukraine has managed to mitigate that attack since then; Kyiv hasn't had a power outage for about 2 weeks).

It's also notable that Ukrainians aren't responding to this by installing solar on a large scale. In this climate it's just too expensive for not that much power. There is a bit of solar. But it's pretty minimal. Wind isn't being installed either.