Recycle solar thermal??

deegs

So I just picked up 20 solar thermal tubes on a mount that had been cut off a roof by PV installers last year. I just picked them up yesterday but there is no controller, expansion or pump with them. I have a brand new joule twin cylinder with solar thermal input but I've no idea what I need now to connect them up? Not much on the old thermals online... Is it worth my bother. I have almost unlimited space for PV... Is it worth hassle to buy all the extras to run the thermal, can anyone rec omed what I need... Hope I didn't stumble into a money pit!

deegs

Installed in 2016 on a new build so newish. Not sure on make but there was a joule solar stainless tank. No sign of any other kit.

Jonathan

https://www.boards.ie/discussion/2058333547/recycle-solar-thermal

People dismiss solar thermal but it is still the best way of heating water during the summer months, saving more PV for export rather than divert. The other thing to consider is the location and the length of the immersion element in your joule twin cylinder. My element is half way up the side of my twin cylinder so the immersion alone can't heat the whole tank (unless you look at a destratification pump or an external Willis heater).

If you're up for doing the plumbing yourself, all you need is an expansion vessel, a circulation pump (both of these could be second hand from a wet heating system) and something to turn the pump on and off when the sun is out. That thing could be a proper pump controller, yourself switching it on/off manually, or automate it using a smart relay and something like home assistant.

Keep an eye out on adverts, pump control stations pop up from time to time.

deegs

Great insights, much appreciated! I like the diy approach to using a wet system pump... Thought I'd have to fork out a new controller.