I made a solar
panel on my previous boat.
It was 13" x 50" size with 1/2" copper pipe, parallel flow.
It was covered with plexiglass on top and 1" styrofoam and peel and stick shelf cover vinyl on the bottom.
It was incorporated into my solar
panel arch over the aft area of the cockpit
A 12 volt differential controller with a sensor on the output of the panel and another on the top of the pressure water
tank controlled a magnetic drive March pump.
The hot water output from the panel was teed into the hot water output of the boat's hot water tank, and the cold input of that tank was returned via the March pump to the panel.
The system was transparent as far as operation was concerned.
The pump only ran when the panel was hotter than the tank.
We always had hot enough water on tap to take a shower
, even in the middle of the night.
I took another direction on my current
By using Aerogel in our refrigerator
build and also using it by reinsulating our hot water tank, we now make hot water by turning on the inverter
I must say it's a much more streamlined and less cumbersome way to get hot water.
We never need to run the engine
for electricity, but LiFePo4
batteries also made a sizeable difference in the equation.
See the LiFePo4
for house batteries thread.