Storing Energy As Heat

For storing heat to heat a home, it's a closed system. You only need to fill it once, topping it off once in a while if/when needed. Typically people use a few 55 gallon drums. The water is cycled through a pipe contained in a solar collector outside to heat the water, then stored in the 55 gallon drums which are inside, with an outtake running the water back through the pipe in the solar collector.

I suggest using a garden hose to fill the system, but you can haul water from a lake, river, ocean, etc., if you think it's best, although salt water is very corrosive.

There are open solar water heater systems to replace/supplement traditional gas/electric hot water heaters. These can be as simple as painting a garden hose black, placing it in a solar collector like the ones used for the pop can heaters, and hooking it up to the hot water pipe system. These solar water heaters are also useful for heating pools and hot tubs, recycling the water that's already used in both.

There's a number of designs for making DIY solar water heaters that anyone with basic skills and materials has, as well as commercial products, both of which are just as "sustainable" as the hot water heater you're using right now.

Solar heating of any kind isn't dependent on the outdoor temperature. The only thing that really matters is the amount and degree of sunlight.

This video shows the most basic solar water heater. With a few simple enhancements it could be even better, such as putting the tubing in a solar collecting box and insulating that box, like shown in the pop can air heater videos. I'd also spray paint the plywood used black.

The water temperature created with this system is much hotter than most typical water heaters and can save a lot of money by filling a typical water heater with hot water heated from the sun.

Now I get it...sounds like a good idea and is similar to my comment about how the Monguls heated clay.


I'd be tempted to use a parabolic dish array so it could "track" the sun throughout the day better. Either way, during the summer just cover or remove the solar concentrator.


I haven't tried it myself, as I don't have a good southern exposure, but I've heard people simply painting a window shade black so it absorbs the heat and not reflect it back out the window. There's a gap of an inch or two between the shade and the wall, so the heat rises. They say this is pretty effective.


When I lived in Las Vegas, I noticed a few homes put aluminum foil on their windows to reflect the sunlight, so I tried it myself. This simple thing had a pretty dramatic effect on the temperature in my bedroom.


Simple things like this can be very effective. I bet the 50 cents I spent on foil saved me hundreds of dollars on my electric bill over the years, not to mention the environmental benefits of using less energy.