I'm working in the Power Systems team of CubeSAT. It is concerned with building a small student satellite with dimensions of 10x10cm. Our basic block diagram is as follows Solar panels-> In parallel Shunt Regulator -> Buck Converter->PRU (MAX8934A)->DC-DC Converters->Loads The shunt regulator used is a Power MOSFET that is turned ON only when the operating voltage of the panels increases above 14V. The major doubts I have are listed as follows: 1. Excess power dissipation : If at a particular time my system power requirements are lower than what the solar panels are able to generate in that particular condition then will the panels automatically generate lower power or is it necessary for the shunt regulators to dissipate the excess power? The professors guiding us on this project are mainly from CS Engg. and believe that the solar panels only generate what is required. I believe otherwise. Am I wrong? They may be true in Solar Panels connected in Direct Energy Transfer connection but how about when connected with a Buck Converter in series? The operating point then should depend on the input impedance offered by the converter(hence the operating voltage) and hence power developed will vary. So don't we need a current and voltage monitoring system and with continuous monitoring dissipate the extra energy by using the Power MOSFETs that are connected in the shunt? 2. Maximum Peak Power Tracking - In this system with changing duty cycle, the impedance as offered by the converter defines the operating voltage of the panels. What I don't understand is how do we control the duty cycle of the converters that are available in the market?