Patent ID: 7905049

Claim:
A method of producing algae, comprising: providing at least one open body of water having an algae population in suspension, wherein the open body of water consists of at least one of: a lake, a river, a natural pond, a man-made pond, and a stream; heating the open body of water with a heat exchanger located in the body of water and connected to a waste heat source, the waste heat source being selected from the group consisting of: a power plant, an industrial process, a cement plant, a kiln, an agricultural product processing plant, a processing plant, an incinerator, a furnace, an oven, an oil refinery, a petrochemical plant, a chemical plant, an ethanol plant, an amine treating plant, a natural gas processing plant, a steel plant, a metals plant, an ammonia plant, a coal gasification plant, a refinery, a liquid synthetic fuel plant, a gas synthetic fuel plant, an industrial plant, and a manufacturing plant; wherein the heating the open body of water with the heat exchanger comprises moving a fluid from the waste heat source through the heat exchanger, the fluid being selected from the group consisting of: hot gas, hot vapor, and hot liquid; wherein the fluid from the waste heat source does not come into direct contact with the algae population in suspension in the at least one open body of water; and growing the algae population.