The paper presents an error driven controller for maximum energy utilization of photovoltaic PV renewable energy interface schemes. The error driven comprises of regulation loops ensuring on-line dynamic tracking of the maximum power point under different variations in solar insulation levels or sudden mechanical load excursions. The bang–bang regulator limiter block is self-adjusting as it is driven by the error excursion vector magnitude. This ensures that the control signal is modulated in magnitude by the distance of error deviation in the error hyper plane. The paper details a digital simulation MATLAB/SIMULINK model of a PV−PMDC motor utilization system driving a ventilation, pumping or air-conditioning mechanical load. © 1998 John Wiley & Sons, Ltd.