Abstract: Instead of supplying all electrical current for residences or similar buildings from a single central station by way of distribution power lines, each building is also provided with its own engine-driven electrical generator the output terminals of which are connected to the power lines. The heat from the engine in each building is used in satisfying the thermal load for that building, for example to heat the building and the domestic hot water, and/or to supply heat for heat-input forms of air conditioners or refrigerators. Thermostatic control is used to turn the engine on and off as needed to perform its heating function. The electrical current generated while the engine is running is used to supply part or all of the electrical load in the building, and any excess is supplied to the distribution power lines. A two-way watt-hour meter registers the net electrical power flow in or out of the building to enable securing of credit for the current delivered to the power lines from each building.