A few years ago, solar panels dropped a lot more than 10% in efficiency when they got hot. I can see investing in water cooling them back then, but suspect tha

A few years ago, solar panels dropped a lot more than 10% in efficiency when they got hot. I can see investing in water cooling them back then, but suspect that technology trends have already made this product obsolete. If they really can cool the panels at a price + reliability + installation complexity comparable to conventional panels, it might be worth it. However, our heat pump water heater is under 10% of our electricity bill, so if it's cheaper to just add 10% more panels + batteries, then this product seems like a non-starter to me. I guess it's possible this would make sense for heating swimming pools (they create an extremely large reservoir for the waste heat during the summer).