We have passive thermal heat tubes on our roof to heat our pool. It works amazingly well. I want to put PV on our roof, but that’d mean having to pull up those tubes first and replacing our pool heater with something electric.
Turns out there’s companies that do hybrid systems! Water is used to cool the PV, increasing the efficiency of the panels in the process, and then the heated water is used wherever you need it.
Unfortunately it seems there’s only a couple of providers, it’s rare to find installers that do it, and it’s ssuuuppppeeerrr expensive relative to the normal options. Such a shame. I wish there were more options here. It seems like a great approach.
It's more claim than reality. The addition of water radically increases install costs (the main cost driver!) and dramatically reduces reliability.
If you fully price it out you'll find it's more cost effective to just spam more PV and use a heat pump, unless you've reached space limits.
We just did the opposite and ripped up our solar hot water system. We have a metal roof and a salt water pool. Problem is that these systems can and do leak. Salt water on a metal roof makes creates rust.
With photovoltaic panels being dirt cheap, we decided to rather heat our pool with a heat pump that is powered by our own electricity.