Check out https://solar.lowtechmagazine.com/

If I didn't live in the woods (and thus mostly in shade all day) I'd totally build a solar hot water heater. I've managed to reduce my showers to about 3 gallons, heating that much up with some black pipes on my roof or driveway would be extremely doable.

This post was duplicated twice (that's what the other user's were informing you of in the other duplicates). I removed the two other duplicates and kept this one as it had the most upvotes.

I only submitted it once but noticed it took an exceptionally long time. Apologies.

How do you connect it to your existing hot water system though? Already got a heat pump too, when you have the most sun the heat pump barely uses any power for hot water and don't need much.

I have wondered about solar/fire heated pool or hot tub, but that is adding energy demands in the first place. That said with the heat lately a cold pool could be nice. Can get 5000L for just under £100, 3-4m wide. Heating it could make it usable into autumn though.

There's different ways to do it iirc. It can either remain as a separate system for hot water or connect directly into the hot water heater and offset the energy costs for running it.

My showers are about three gallons because I'm not actually using my plumbing, I'm using a separate camp shower. It'd be pretty simple to just dump the hot water from the solar heater into the shower bucket in that case.

I thought that was next year's samsung s27

This idea also appeared very strongly in Technology Connections' recent video on ceiling fans, which fell out of use with the rise of air conditioning. Even though they work really well together with air conditioning...