A thermal source provides heat to a heat engine and or one or more thermal demands, including space and water heating and heat storage. Additionally the output of the heat engine may be used for local in situ electricity needs, or directed out over the grid. A system controller monitors conditions of the components of the system, and operates that system in modes that maximize a particular benefit, such as a total accrued desired benefit obtained such as reduced electricity cost, reduced fossil fuel use, maximized return on investment and other factors. The controller may use past history of use of the system to optimize the next mode of operation, or both past and future events such as predicted solar insolation.