PV Array

A funny thing about this project: The Solar Panel/Battery Bank/Inverter system, which in the wider world might be considered new and untried technology, is in our case the solid, standard, tried-and-true platform on which we built the really new and untried hydrogen fuel cell system.

We have a PV (photovoltaic) array of ten 150 watt panels. The array sends current at 48 volts DC to an Outback Charge Controller. This is designed to constantly monitor and alter the output voltage in order to maximize output power. It also prevents over-charging of batteries.These charge controllers are total black magic. The one we hooked up to the fuel cell (see 24 vs 48 Volts) extracted 1300 watts from a 1000 watt fuel cell (!).

The charge controller sends current to the batteries at 24 VDC (nominal-really 26 to 31 volts). Thus properly speaking the PV array charges the battery bank rather than running the electrolyzers directly.

When the sun is shining and the batteries are full the electrolyzers turn on (see Remote Operation) and the PV array power then runs the electrolyzers. All solar power still runs through the charge controller into the batteries first. It then goes to the inverter which provides AC current to the electrolyzers.

The main panel. The inverter is the shoebox-sized thing between the two large panels; the charge controllers (one for the array and one for the fuel cell) are on the far right.
An Outback Charge Controller