A supervisory system controller for controlling and monitoring the generation of electrical energy from renewable sources and management methods for the storage of energy so generated and interconnecting the energy-generating elements, storage and load. The supervisory system controller operates to maximum the power transfer from a wind turbine to a battery by automatically varying the threshold levels at which turbine dump loads are switched based on system inputs and measurements. The method conserves generator fuel by delaying a scheduled generator maintenance running period such that it occurs when renewable energy availability is predicted to be low and battery is in a reduced state of charge. Further modifications and management methods are also provided.