>>528388847
Generators are not efficient when they're not working at 100% power, read the tooltips. It's best to put them on full throttle to charge up the flywheels and turn completely off while they discharge.

Protip: If you have for example 2 generators, each producing 4kw, and you're constantly consuming more than 4kw, disable auto balancing thing for one of the generators, so it works always, instead of having two of them constantly cycle on and off (losing efficiency when starting up)