Abstract: The present invention relates to a combined interdependent fish and plant factory. An embodiment of the present invention includes a fish house connected to a greenhouse, a biofuel source, and a generator connected to the biofuel source and to at least one of the fish house and the greenhouse, where the generator is adapted to utilize biofuel as a fuel source and to provide electrical power to at least one of the fish house and the greenhouse. An embodiment can also include a waste heat recovery boiler or an algae reactor. Another embodiment includes a method for growing plants and farming fish in a combined interdependent fish and plant factory including a fish house connected to a greenhouse, including the steps of utilizing biofuel from a biofuel source to create electric power, and providing the electric power to at least one of the fish house and the greenhouse.