MAILBOX: Solar Bus

Electric VW bus
Daniel Theobald’s PV-powered 1966 VW Bus.
The business end of the VW EV
Daniel Theobald’s PV-powered 1966 VW Bus.
Electric VW bus
The business end of the VW EV

Blue skies, not a cloud in sight. A great day for driving a typical 1966 VW Bus; a perfect day for an electric bus with 10 solar-electric modules affixed to the roof. I bought the bus to convert it to electric, and took it a step further—with solar. The bus might look a little funny, but it’s proving that solar powered vehicles can be practical.

The conversion process was a lot simpler than I expected and took only a few days. The first thing I did was connect a potentiometer to the throttle. Then I removed the engine and replaced it with an electric motor. After that, I connected a motor controller and the batteries. It was then ready to drive!

The components used are:

• Elmo motor controller

• Moog brushless motor

• Solbian solar-electric modules (10, 130-watt modules on the bus; 20, 100-watt modules on trailer)

• Genasun solar controllers

• Manzanita Micro battery charger

• Boston Power’s Swing 5300 lithium-ion batteries

This vehicle is great for city driving. Slower, flatter routes are best. Driving this vehicle has made me think about the routes I take when driving a normal vehicle. There’s a big hill on the shortest route to my kids’ school, and I watch the battery drain as I accelerate up the hill. Taking a slightly longer, but much flatter route uses just a quarter of the energy. Avoiding hills and opting for routes at slower speeds yields optimal results. Routes with more sun and less tree overhang also increase the range.

The bus can go 74 miles per hour, but again, going that fast wastes a significant amount of energy due to wind resistance. It has a range of about 35 miles if there’s no sun, based on energy stored in its batteries. Range could be increased by simply adding more batteries, but would also add weight and cost.

The bus gets a lot of attention. When I first bought it, my kids would not go near it. They were so embarrassed, but their friends thought it was so cool. I also often get notes left on the windshield when it’s parked somewhere, sometimes because it’s an old VW bus, other times because it’s solar powered. People have actually stopped in traffic to wave or ask me about it.

Daniel Theobald • Cambridge, Massachusetts

Comments (9)

OceanPlanet's picture

Hi Daniel,
Great to see the Solbian panels in action (we sold them to Vecna!). What is the most output in watts you have seen?

Daniel T.'s picture

Haven't measured it per panel directly. We have each panel feeding directly into the battery bank. We are going to do some work this summer that will provide precise energy measurements throughout the entire system. Thanks for the panels, they are awesome.

OceanPlanet's picture

Very are going direct to the battery, but though a controller, right? What voltage is the battery?
Ok to show pics of the van? It's a classic!

Daniel T.'s picture

We charge through Genasun boost MPPT controllers. Currently the bank is 24 12V batteries in series. We are upgrading to a Vecna built 768V lithium pack in the spring. Sure, show away.

Winnen's picture

We neet to step up and teach the kids life im of the grid in San Diago we need to love our planet

Winnen's picture

way cool i think in hawaii would be perfect

Kevin Shea's picture

How you secured panels on a roof is a mystery.

Michael Welch's picture
The modules are Solbian flexible. It looks like he built a rack with some good gutter clamps, and adhered the modules to the rack.
Daniel T.'s picture

Michael, you are right. That is how I attached the panels.

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