Energy independence . . . for your overland vehicle

This will come as a shock to many of you, but it is actually possible to camp without electricity. 

Reliable visual records from the Middle Ages (1950—1985) clearly show families surviving—even, at times, apparently enjoying themselves—in campsites lit only by white gas or propane lanterns, retrieving food from insulated boxes cooled only with ice, and engaging in such non-electrically dependent activities as fishing, swimming, climbing trees, and reading books manufactured in the ancient Gutenberg manner, on paper. (A few disputed images even purport to show family members talking to each other.)

Of course it’s easy to idealize scenes in vintage Kodachrome transparencies. What isn’t so apparent are the tragic effects of those primitive times: respiratory problems from second-hand kerosene smoke, salmonellosis caused by eating chicken stored at above-optimal temperatures, blindness brought on after repeated attempts to read Field and Stream by the light of a candle lantern (not to mention the devastating tent fires also associated with open flames), ugly cases of fratricide sparked when siblings were forced to interact directly with each other. (“Where’s Timmy?” “I don’t know, mommy. Maybe a bear ate him.”)

We can thank the advances of civilization—the Cree, the Engel, the earbud—for the blessedly longer median life expectancies now enjoyed by overland travelers. But LED lanterns, 12V fridges, and the myriad of electronic entertainment and communication devices now virtually grafted to our persons—they all require electrical power. Those of us who’ve moved even farther upmarket with such things as truck-mounted campers need yet more, for water pumps, vent fans, heater blowers . . . although personally I’ll draw my line of sympathy this side of anyone who wants to power a flatscreen TV in the wilderness.

An auxiliary deep-cycle battery has become nearly standard equipment for a well-sorted overland vehicle, and with good reason. It keeps the starting battery free for its critical duty, and serves as a starting backup as well if connected with a selectable isolator such as the National Luna (although the advent of the brilliant Micro-Start and similar products has made this function nearly redundant). With a battery monitor it’s easy to keep track of usage and voltage.

However, depending on load (especially that fridge), you can run down even a high-quality Group 34 AGM battery in anything from six or seven days to less than one. If you’re on the move day to day, it’s likely your engine’s alternator will be more than adequate to bring the voltage back up to an ideal float level of 13.4 volts or so. But what if you’ve found the perfect beach or forest campsite and don’t want to move for a week, or two? Idling the engine is a notoriously poor (slow) way to recharge a battery, irrespective of the fact that you’re pointlessly burning fuel, causing pollution, and spoiling your ideal campsite with noise. You need a different power source—and the finest one you could ask for is a mere 93 million miles away.

For years auxiliary photovoltaic (PV) solar panels for vehicles fell into two broad categories and capabilities: You either had a permanently mounted rigid unit or units of decent (50 to 200 watts) output installed on the roof with brackets, or you made do with much smaller flexible PV panels which clipped directly to your battery and could be laid out on either the hood, roof, or ground. The former, while sometimes capable of maintaining auxiliary battery voltage nearly indefinitely, were bulky and heavy, and created serious overhead hazards for tree limbs, etc. The latter were rarely if ever capable of doing more than delaying the necessity for running the engine.

That’s all changing. Roseann and I now have two 100-watt semi-rigid PV panels on the roof of our Four Wheel Camper; attached directly to the roof via stout adhesive backing, they create essentially no windage or clearance issues, and over many trips have proven to keep our auxiliary fully topped up to run the camper’s fridge, (LED) lights, vent fan, and water pressure pump, and recharge capabilities for our extensive array of journalist-oriented electronic devices and cameras.

And now it’s possible to get that same level of input with a completely portable kit displayed by P3Solar at the Overland Expo. Their 200-watt flexible panel weighs barely five pounds, and rolls into a 35-inch by 5-inch tube. While it obviously takes more time to set up than a permanently mounted panel, you can use it on different vehicles, and if you want to park in the shade you can run the panel out into the sun (although since the panel is equipped with bypass diodes it handles partial shade quite well). Your roof is also now free for bicycle or kayak racks, or a roof tent.

The P3Solar panel connects with standard 2-pin SAE plug. You could run that through alligator clips and simply hook it up directly to your battery, but with that much input you’d need to monitor the system very carefully to avoid exceeding maximum voltage. Much better to run it through an MPPT (maximum power point tracking) charge controller, which will optimize the unit’s 24-volt output. A standard charge controller will work as well, but will pull the voltage down a bit and thus not exploit the panel’s full output.

The panel can be deployed by laying it flat on the ground; however, the company also offers a clever folding aluminum frame that positions the panel at a more optimum angle for those in latitudes above the tropics. It expands accordion-like in about five seconds and snaps into place; the panel then attaches to it securely with Velcro. The frame can be (that is, should be) staked to the ground with included stakes that are stouter than anything I’ve ever seen included with a family sized tent. Impressive. Thus anchored the assembly shrugged off a 20mph breeze out at our desert camp; Wally Stoss at P3Solar assures me it’s been tested at over twice that. The EZ-out kit include a larger diameter bag and a rigid tube to separate the panel and frame, and the whole kit is still under 20 pounds. 

On a very warm (95ºF) summer morning with the sun still low, I recorded a bit over 100 watts out of the panel mounted on the frame. Since PV output is lower in high temperatures, and obviously lower when the sun isn’t directly overhead—and since most PV panels never see their theoretical maximum—this is astounding performance. Most fridges draw in the neighborhood of three amps (36 watts at 12volts—and of course only intermittently), so I was already well ahead of that. 

It’s clear the P3Solar panel would give most overland vehicles complete electrical independence—and then some—for as long as you wanted to stay and enjoy that beach. I’m curious what the output of this panel will be in colder temperatures with the sun overhead. Imagine selling your excess electricity to fellow campers . . .

P3Solar is here.