Why limit the use of the exquisite CAN bus to in-vehicle sensorics? That’s what the author thought when customers, installers and authorities bickered about disappointing results from a 25 kW solar cell array on commercial exploitation. Here’s how an electronics system got designed to read out the power yield of each PV panel individually along with its number so the serviceman can pinpoint it and clear the source of the problem (literally — read on).