Renewable energy was a major theme at MIT’s 100K business plan competition this year. One of the two top winners, announced last night, was a group called Bargazo, for a process it’s developing to turn corn cobs and other agricultural waste into affordable cooking fuel for the developing world, as an alternative to wood or oil.

The other big winner was Robopsy, a remote controlled robot that can assist radiologists in targeting tumors. Both winners will receive $30,000 each.

Two of the four runners-up were also energy related. C3BioEnergy would produce propane and hydrogen from crop material. Promethean Power would build a solar power generator that can heat, cool and generate electricity.