Latest posts by Stephen Lloyd Webber (see all)
- Writing From the Inside Out – now available as audiobook! - January 17, 2017
- Live Culture Hot Sauce – Fermenting peppers to make a spicy sauce - April 7, 2016
- The Ergonomics of Emacs (with Colemak and Ergoemacs) - March 10, 2016
A cold shower is pretty straightforward. But a hot shower — that’s something else. To get hot water, you need a water heater of some kind. We opted for an on-demand propane water heater. For the on-demand water heater to work, we needed to boost the water pressure, so we needed a water pump. To power the water pump, we needed a battery bank. To keep the battery bank charged, we opted for a 45 watt photovoltaic panel and a charge controller. Most everything can be ordered from Amazon, though I recommend Real Goods for the solar equipment.
Maybe that all seems a little complicated. Maybe you want something simpler, something for occasional use. Here’s a brief rundown of some options to help you achieve your loveliest shower goals.
First, Other Options
There are other good options available for solar hot water. The most basic solution starts with the basic camp shower, which is, well, a black plastic bag with a spigot:
It’ll do the trick.
The irony with rudimentary solar hot water is that when you most want the water to be hot, it’s cold, and when you most want a cold shower, the water is scalding.
What About Solar Thermal?
Solar thermal is a great option because it eliminates the propane use. We didn’t go that route because it was a slightly more complicated system than we wanted.
Solar thermal systems use panels that water circulates through, heating up in the sun. They often make use of a really small pump to circulate the water into an insulated storage tank (you can repurpose an old water heater tank for this).
These panels are great. One potential downside is not having sufficient hot water storage so that you run out of hot water while you’re showering.
An ideal all-year setup would use solar thermal as a pre-heater, relying on propane as a backup. If you size the system correctly and get enough of those solar thermal panels (and a big well-insulated hot water tank), the propane heater would not be necessary. How to configure such a system would need to be based on how much your shower gets used, amount of sunshine, ambient temperature, and such. Much depends on your situation and your desire.
The Propane Heated Shower With Solar Pump
If your water source is already pressurized, you don’t need the solar cell or the water pump. You can simply connect your water line to the propane heater and it will work fine.
As mentioned above, our water pressure was gravity-fed and so not high enough to get the propane shower unit to kick on. So we needed a pressure booster pump.
Most any 12volt pressure booster pump will work. This one is rated at 2.9gpm 50psi. It’s pretty quiet for a water pump. The noise is not unpleasant. Putting the pump in any sort of enclosure will significantly diminish the pump noise. Just don’t put it in the same container as the battery bank. That would be unwise.
As a temporary thing in a good climate, you can use a really simple container (above) to keep the batteries and connections water-tight but vented. Be sure to connect a fuse between the pump’s positive wire and the battery connection.Here, the water pump is mounted on the outside of the battery bank. (Yes, those are stinging nettles.)
The Tweak: Hard-Wired Ignition
The shower’s little electric ignition thing is powered by a couple of D cell batteries. I removed the little enclosure where the D batteries go and hard-wired it to my battery bank. My battery bank is 12 volt, and so I connected a 3 volt DC-to-DC converter in between the battery bank and the shower. It works great, it’s always at max voltage and you never have to change batteries.
What’s a DC-to-DC converter? Lots of options here. I had a spare 12v cigarette lighter adapter kit that I set to 3v.
It’s a lovely shower, and the water from the shower goes right into a shower garden.
No pipes. The water runs right off the slate through a concrete channel and into a small reed bed.
Be sure to only use good soaps (like Dr Bronners)