A computer processor implemented method of measuring utilized generation of at least one at-premise power system to a consumer, the method comprising the steps of; providing at least one at-premise renewable power system, at least one meter in communication with at least one said at premise renewable power system and at least one wireless communication node in communication with at least one meter; determining usage from each meter, wherein at least one of the meters collects usage data from at least one at-premise renewable power system. A first meter collects data input from a pulse meter to provide primary input, a second meter collects data input from a secondary source meter to provide secondary input and the utilized generation is arrived at by subtracting the secondary input from the primary input.