Daylighting, a Trombe wall for passive solar heating, and downdraft cooltowers for natural ventilation cooling save about 10 kilowatts of electrical demand. An energy management computer collects weather data and ensures that all the features work together. It controls the cooltowers, radiant ceiling panels, lighting, and windows. A roof-mounted photovoltaic system provides electrical power, reducing the amount of power purchased from the utility and supplying backup power when grid power is not available.