We interviewed an engineer and a couple on a road trip, both of whom travel in solar powered van conversions. They share tips on equipment, charging, cost, and more.
For Tressie Word, living in a solar-powered home in Portland, Oregon wasn’t enough: she wanted her van for short adventure trips to run on solar power as well. So she added solar energy to her 2015 Ford Transit, to power its cooler-sized refrigerator, fan, recessed lights, movie projector and electric blanket.
“It was 100% DIY,” says Word, who hired no installer and did the work herself, from drilling holes in the van roof to attach solar panels to choosing all the components needed.
The senior engineer in stream and wetland restoration at Portland’s Bureau of Environmental Services bought her solar equipment from Renogy, a California-based company, and also bought an external 1000W inverter. Her solar array, which cost about $3,500, took two days to install in 2020 and ensure everything worked properly, including wiring, testing and troubleshooting, she says.
Minor issues included switching and resoldering cable ends, as she didn’t get all the right cables, and the van engine underneath the driver’s seat was hard to reach.
Since then, it’s “worked seamlessly,” she adds. “It’s amazing – a wonderful way to travel. In addition to the solar, every time you drive the van the alternator charges the batteries.” The things she loves most? “The fridge – it’s so awesome to travel on the road with a fridge that makes solar ice – and the giant electric blanket for winter ski trips.”
The first step is to size your system, to figure out how much electrical power you need based on your desired appliances, charge capacity and lighting in your van, to see how many panels and batteries to use.
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System sizing guidance and descriptions of solar-powered van conversions (and a photo of Word hard at work on her solar installation) are in To Catch the Sun, a free e-book about DIY solar power. The 207-page how-to book is by Lonny Grafman, lecturer in environmental resources engineering at Cal Poly Humboldt in northern California, and Joshua Pearce, chair, information technology and innovation at Western University’s Ivey Business School in Ontario, Canada.
- Place your solar equipment for easy access, so you can see your controller and get to switches easily. The box with controller and inverter is tucked affixed to a wall under her king-sized bed, along with bikes, surfboards and paddleboards. (“The bed takes up lots of space in the van but it’s great for storage.”)
- Parking in the sun is important, since the amount of solar power to charge the batteries is inconsistent, and much less if parked in the shade or during cloudy weather.
- Connect the solar batteries to the car battery using a smart isolator, so the van charges the solar array while the engine is on.
- Keep the solar panels clean, free of dirt, leaves and pollen. She uses a soft brush.
- Store a ladder in your van for maintenance of the roof panels.
- How you wire panels is important. Parallel systems handle shade better than series.
- Be thoughtful about the kind of batteries you use and how much to draw down. While lithium batteries last much longer, can be drained much more and are much lighter, they’re expensive, so she uses lead-acid batteries. A 120 amp-hour (Ah) lithium battery costs about $700. Her two lead-acid batteries cost $300 each.
- The external 1000W inverter connects directly to the solar batteries, which requires manually checking to see how much the batteries are drained. Other products may integrate an inverter into the controller system to automatically prevent draining the batteries.
- Always check how much appliances need to run before plugging then into the inverter. Her 1000W inverter cannot power a typical blender or coffee maker.
- Renogy 480W flexible monocrystalline panels (three panels, 160W each)
- Rover Charge Controller (connected two lead-acid batteries)
- Keyline Iso-Pro140 smart battery isolator (allows charging from the van engine, and protects the car battery if the solar batteries fail)
- Xantrex PROWatt SW 1000W inverter
- Maxxair MaxxFan Deluxe fan
- Dometic CFX fridge with ice maker
Word is a professional engineer, who currently manages restoration and treatment plant projects in Oregon, designed natural wastewater treatment systems in California and Mexico, and worked in Guam on storm water planning at the airport and expanding a commercial port after getting her engineering degree at Cal Poly Humboldt.
But you don’t have to be.
Another solar van conversion story
A young couple who chronicle their road trip from Canada to Argentina on the Pan-American Highway, living in their solar-powered van conversion, on their blog Asobo Life weren’t. But Eric Yu and Yuko Shimokawa embraced the challenge.
“As urban Asians from Hong Kong and Japan, our DIY abilities were zero. ZILCH. Nada,” says Yu, who explained that after years of computer work, they craved creating something tangible with their hands, not digital, for their journey, which began in 2019. So they learned woodworking, electrical work and plumbing to broaden their skills, have new experiences and travel the world without leaving their home, a 2018 Ford Transit.
The Asobo (“let’s play” in Japanese) duo discuss calculating how much solar power your van needs, based on battery type, in this post.
Merely adding up the electrical requirements of all the devices in your van – which may include a laptop, hair dryer etc. – is erroneous, “because solar panels power batteries, not devices,” they say. If you have lithium batteries, aim for a 1:1 ratio minimum of solar watts to total battery amp hour (Ah), they suggest. If you have lead-acid batteries, aim for a 1:2 ratio. Their van has 300Ah of lithium batteries and 350W of solar power.
Their solar installation was more expensive than Tressie Word’s, and cost almost $6,000, including two solar panels, lithium batteries, inverter, charge controller, battery monitor, wires, circuit breakers etc., Yu says. But solar van conversions for different budgets are described in Asobo Life.