Passive Solar Hot Water Heater

Kaxil Kiuic is “off the grid”, meaning its power is self sustaining. The electricity comes completely from solar power stored in batteries. As well, there is a well pumped by the solar energy and then stored in tanks through out the camp. The only hot water found on site is heated on the stove.

So, one of our projects was to build a passive solar hot water heater. The way it works is quite simple. This cool piece of machinery takes no power and the water runs through it because of physics. As you can see from the photos a snaking form of pipes sits on top of a stand. The stand angles toward the southern sun, which provides the warmest solar heat. The pipes are painted black to absorb more heat.

Cold water flows into the pipe form and then (if the sun has warmed the pipes) heats the water. The solar heated hot water then flows into the shower or faucet through a another pipe at the top of the form. The nifty part about the heater is the cold water enters at the decline of the pipe form and then the hot water rises through the pipes because of physics. Dr. Galicki explains this part but it becomes extremely confusing, so I cannot explain the full process.

This type of water heater provides hot water only during the times when the sun is shinning. So showers at night will most likely still have cold water. We have discussed different ways to insulate the pipes, especially local alternatives. This is an interesting part of the course and permaculture, discovering sustainable ways through cultural history. The Maya used a certain type of construction called dobb and waddle. This process involves creating walls using alternating long sticks. Then the inner area is coated with a mud paste which hardens and creates a solid surface. This creates an insulation barrier. We discussed using this to have an insulator for the hot water and be able to use it more often.

The construction of both hot water heaters taught each of us a lot. Dr. Galicki helped each of us learn something new through the construction. The assembly took group work and patience. The lab activity taught us more than just the possibilities of alternate energy, it teaches the process of team work and effective planning.

Photos helping to explain the process: