So last year I put a 25w solar panel on the shed roof, ran some charging points from it and an inverter for the kids pool filter.
This year I wanted to see if I could heat it for free aswell. Now I don’t expect a bubbling cauldron but if I can get the 3000litres of water to be 2 degrees C warmer it will extend pool time a few weeks.
So I built a solar heater after making a test one, that warmed 100 litres of water to 32 degrees C in 2 hours. The final one I built has double the pipe work and a proper K Glass double glazing panel. I’m flowing roughly 4 litres a minute with 1 pump and 6 litres a minute with 2. So in 10 hours on a warm day I should have run all the water, 3000 litres, through the solar heater. Hopefully this is actually noticeable and not just a complete waste of time
The panel is 75 x 120cm and weighs a ton. I’ve used water irrigation pipe throughout as it’s both cheap and the eating point is lower than the flash point of the wood. So if the worst should happen the pipe will fail and fill the panel with water. It weighs about 45kg though which was more than expected.
This is the distribution panel, 4amps of usb power, inside and outside LED lights, a feed to the inverter and a feed to the heater pumps. These are run through the solar controller output though so they turn off at 11V, the 5v loads would be unlucky to kill the main battery but if the pool filter or pumps were left on all night they could hurt it. It’s only a 115ah lead acid leisure battery. I’d like lithium iron phosphate but it’s far too spends for this stuff.
Super cheap solar controller, I think this was £15 from Amazon, I may get a MPPT controller as they are more efficient than this PWM one, if the battery is marginal after a week of use then an MPPT would be worth spending £40.
I found 2 brass bodied pressure washer strainers, it will stop them being knocked by the kids and floating up.
Twin pumps, each has its own feed but a linked outlet, I used normal snap on hosepipe fittings incase the system
Wouldn’t self prime, then you could easily do it with a hosepipe, I think I’ll change this though as it has too much restriction.
So currently with both pumps and the pool filter running I’m drawing 8 amps and only putting 1.5A in. This should be ok as the pool filter won’t be running permanently but I think after about 4 days of all day use the battery would be pretty much spent. So I added a paralell solar connection through a Ctek connector to add our camping panel in which puts out about 4amps on a sunny day.
It will be an interesting experiment and as the plan is to run out next houses workshop purely away from the grid it’s exciting in general.
Dave!
I’m sure it works to retain heat a bit, but we can’t use it because the cats think they can walk on it.
