Abstract: An energy management system includes one or more electric power generators located at or near a consumer's premises, to provide power which is dedicated to the needs of that consumer. The power provided by the on-site generators complements that which is delivered via a centralized power grid network. In the event that the power grid is disabled, or is otherwise unable to provide adequate power to the consumer, the on-site generators are switched to provide power to critical equipment. In one embodiment, a computer-driven control facility selectively actuates the on-site generator to intelligently arbitrage between the locally generated power and that which is provided via the grid network, based on a variety of factors. The instantaneous cost of power supplied via the grid network is compared against stored costs of operating the on-site generators, such as the price of fuel required to run the generators, maintenance expenses, other types of service and installation expenses, and finance charges.