People have tried running water to cool solar panels. It is a bad fit. Plumbing is a source of trouble; the more fittings involved, the worse it gets. Somebody

People have tried running water to cool solar panels. It is a bad fit. Plumbing is a source of trouble; the more fittings involved, the worse it gets. Somebody is selling plastic frames you attach your panels to, to blow air through to cool the panels and claim the excess heat. Air ducting makes less trouble than plumbing does. The air can go through a heat exchanger attached to a heat pump to concentrate it. Keeping the panels cool increases their efficiency enough to pay for the fan and heat pump, and makes them degrade much more slowly; and, you get the heat if you want it.