Mining gens = more money, it also = less energy. Money is essentially worthless on here. But to run a cell it's a expense in energy, a big expense. Meanwhile, mining in a cell pays less energy than mining meteorites or in the mines. The reward for having a cell? Less energy acquired for time spent mining, and more expenses.... seems wrong. You should be getting extra energy for cell mining, that in the long term (1 month+) pays more than the mines. The expense of guards is absorbed in the short term for long term gain for running the cell.