Allow normal generators accept Overclocker upgrades, each upgrade increases EU output by 5.
Fuel is consumed faster due higher output. for example a generator with 2 OC will burn stuff 2 times faster (20EU/t)
or
Allow normal generators accept adjacent blocks (like LESU, GregTech addon) to increase output/fuel usage.
Adjacent blocks should be a new block, non-tile entity. Recipe could be Machine block + 2 circuit
These would allow consume of higher amounts of fuel easier. Normal gens are too weak if compared to others nowadays.