Solar water heater update

It became apparent that the solar hot water heater I built from recycled materials had a problem. I noticed that there was always moisture on the lower sides of the tank and a small puddle on the bottom. I gave it over a week to dry but it never did. Obviously, it was leaking. All the plumbing joints were tight so there was some sort of problem inside the tank. I decided to remove the tank and replace it with another recycled one that was in better shape. I closed the valves to remove the heater from the system and was quite excited when I broke the connection on the hot water side at the tank. The water that spurted out was hot enough to shower in! I drained the tank and used the water in the garden. Even the water at the bottom of the tank was lukewarm. This was after only a half day of sun. I'm sure that the constant moisture on the outside of the tank was cooling it as well so I have high hopes for the system with the new tank.

A simple recycled materials passive solar batch water heater, in Bermuda

The 30 gallon water heater tank and mirrors came from a bathroom renovation and were headed for the dump, the double pane windows from an apartment renovation, the lumber from two separate home renovations, the insulation lining the bottom, top and sides came from various packaging materials destined for the dump. The only materials purchased, to the tune of about $200, are the screws used to assemble it, the plumbing supplies, sealant and paint, as yet uncompleted as you can see.





We plumbed it entirely on the cold supply side of the regular electric water heater, this water comes directly from the rainwater harvesting tank under the house. The hot water line from this tank to the electric tank is fully insulated. As hot water is pulled from the water heater it is replaced by preheated water from this little tank, thus causing the electric hot water heater to run less. Valves will allow the solar heater to be dropped out of the circuit without shutting off the water system.

I don't have figures yet but the simple things I did when I moved in, turned down the hot water heater and put an electric crisper on a timer, reduced usage by 60kwh/month. I'm expecting more from this project. I hope to get my Killawatt from the UK to measure usage at some point.

I should also say that I got two contractors to provide quotes for a solar thermal panel system. One was just over $10,000 for a single flat panel and an insulated water tank. This did not include the plumbing. A similar system in the UK would be less than half that. The second contractor never got back to me with a figure. Judy, my landlord, could not afford that size of investment. At that point I began collecting materials.