Maximum power transfer by conductance comparison

Most scientific satellites to date have utilized solar cells as the main power source for the spacecraft payload. Two basic methods have been utilized for operating a solar cell array at or near the maximum power point of its I-V characteristics. These two methods may be categorized as either an open loop system or a closed loop system. An open loop system makes use of design parameters of the solar array whereas a closed loop system constantly monitors some system parameter in order to determine maximum power point operation.