There are a surprising number of possible solutions for producing solar heated water when you are off grid. So many in fact that I could have easily written a 20 Ways or even 40 Ways list, but I decided to distill this topic down to the top 10 ways to make an off-grid hot shower, to give you an overview of the possibilities and potential of this topic. This article will explore my favorite ideas for a portable water heater which include the following methods:
- Portable tankless systems – electric
- Portable tankless systems – propane
- Convection system – passive
- Batch heater system
- Convection system – active or pumped
- Evacuated tube system
- Flat plate thermal system
- Drainback systems
- Pressurized antifreeze systems
- Other assorted solutions
In my experience, which includes time in the deserts of the American southwest and Mojave, as well as the Sahara in north Africa – with its 135 degree daytime temperatures, it is the simple hot shower that has the single most civilizing affect on ones psyche after extended periods in this, or any harsh environment.
Because of the many portable shower products available for the camper or cabin dweller, covering a broad cost spectrum, I thought it would be best to cherry-pick the best product in each category, including DIY, and let my readers decide what would work best for their situation and budget.
Obviously, if your plan is to be wilderness fishing for 10 days and an ‘occasional' shower would be nice, but somewhat optional (please stand downwind), then you will gravitate toward the simple, lower cost end of the solution scale. Conversely, the full-timer or extended off-grid warrier is more likely to move toward the more elaborate products, but this direction will produce the most grid-like hot shower experience. I will start with the least expensive and easiest solution as I see it and move toward the more expensive as the list unfolds. On your marks, get set, go!
1. DIY using a common, coiled garden hose.
This is the simplest, cheapest and easiest passive convection method to create a hot shower because there is no tank or pump or anything other than the collector (hose), which doubles as the shower head, and also does triple duty as a humble hose. I have several black rubber hoses of 100 – 150′ each at my home in Florida. Even on mild, 70 degree days, a coil of one or two of these together in the sun will, after a couple hours, produce gallons of very hot water. Enough to take a quick shower. I have a shut-off valve on the hose end which lets me keep the spigot on at the source, which is my well pump.
When boondocking, the only logistical hurdle is filling and capping the water-filled hose. The best way I've ever seen this accomplished is by dunking the entire coil in the lake or stream and then capping the ends, or in my case, closing the shutoff valves. If this creates too much weight for you, just place the hose coil where it will collect solar heat and fill it by hand using a funnel.
Advantages: takes advantage of existing equipment, the garden hose, and coiling it in the sun is the extend of the preparation. Very easy to pack a 100 foot or so hose in most any vehicle to take along on that ten day fishing trip.
Disadvantages: no temperature control and the water is often scalding hot. Limited capacity, however this can be extended by simply attaching additonal hoses.