At least one embodiment relates to a cogeneration system configured to be coupled to an electrical input of a building and configured to be coupled to a heating or cooling system of a building. The cogeneration system can comprise a generator configured to generate electrical energy. There can be also a fluid output and a fluid input that passes through the generator and configured to absorb heat from the generator. There can also be an electrical output coupled to the electrical input of the building wherein when the generator is operational, the engine creates both heat and electricity. There can also be a processor in communication with the generator, wherein the processor controls when the generator turns on and off based upon the amount of heat or cooling needed, the cost of fuel and the existing electrical rates. These costs can be obtained using communication with real time rates over the internet.