Solar Hot Water

[senormechanico]

I made a solar hot water 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 boat.
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.

[onestepcsy37]

we use the duckworks sprayer tank. cost about thirty bucks. liked it so much i built a second smaller one for about twenty bucks. we also have the common plastic solar shower they sell in camping stores for ten bucks. that works well too.

you can put the sprayer on deck to heat up the water. or you can fill it half with tap water and then half with boiling water from the stove.