E-Bikes Turned Solar Car

There is something to be said for a vehicle that gains range just by standing outside in the sun. In the video after the break, [Drew Builds Stuff] demonstrates how he turned a pair of bicycles into a solar-powered vehicle.

The inspiration for this build started with a pair of 20″ steel framed fat tire bikes [Drew] picked up in a liquidation sale. He welded up a simple steel chassis, and attached the partial bicycle frame and forks to the chassis, using them as steerable front wheels. A short arm was welded to each of the fork, linking them together with threaded rods and rod ends that connect to centrally mounted handlebars. The rear driving wheels are from a 20″ e-bike conversion kit, with the disk brake assembly from the cannibalized bikes.

The solar part of this build comes in the form of three 175W flexible solar panels mounted on cedar frames, coming in at 10 lbs per mounted panel. [Drew] considered using conventional rigid solar panels, but they would have been 4-6 times heavier. The two panels mounted to the rear of the vehicle are on a hinged frame to allow easy access to the electronics below. Battery storage is made up of two 24V 100Ah batteries wired in series, connected to a 60A solar charge controller and the e-bike motor controllers.

The vehicle has a top speed of about 45km/h and 100km range on batteries alone. It might not be fast or engineered for maximum efficiency, but it looks like a ton of fun and relatively simple to build. As [Drew] says, it’s not a how-to for building a perfect solar-powered vehicle, it’s how he built one.

You don’t have to build a solar-powered vehicle from scratch, you could just add solar panels to your existing e-bike or electric car.

20 thoughts on “E-Bikes Turned Solar Car

  1. Brilliant! Not sure how you’ll do in Canadian winter ( ho ho ho) but I did love the refering to the “main frame” in its original sense, not the IBM-mega-computer sense. Great job. Now, does it come in different colours?

    1. Average year-round CoP for a solar panel in Canada or Scandinavia is about 0.05 – 0.07. In southern California it’s somewhere around 0.15 – 0.20.

      The power consumption of the thing is about 48 Wh/km. In Canada you could get around 40 km over the average day. Obviously it would be zero in December and about 80-100 km per day in June. In Southern California you could plausibly go several hundred km in a day.

    1. I’m being generous and assuming you’re not trolling.

      yes if it were standing still and it was windy then it would help to charge the vehicle.
      If it is spinning the turbine because you’re driving, and you expect that to charge the battery; no that would not help.
      That is because:
      1) spinning the turbine takes energy. So it takes more energy to drive with a turbine than without.
      2) energy conversion between wind input and electricity output is not 100% efficient; you would lose energy
      3) energy transport to the battery charger is not 100% efficient; you would lose energy
      4) charging a battery is not 100% efficient; for lead acid the loss can be 50% from charging and then reclaiming the energy later
      5) running a motor is not 100% efficient. So powering a motor to move a car forward which causes fan blades to spin which generates energy for a motor would also lose energy in the motor.

        1. someone who doesn’t know something is not necessarily a moron. You’re not being kind and respectful by using what looks like a straw man attack, which is putting words into someone’s mouth and then attacking them for something they didn’t say.

          I was being helpful by explaining.

          1. It’s not the first time he’s (using alts) setout to waste peoples time by asking to be spoon-fed junior high school science. It is his schtick.

            On a site like this, the third option to troll or moron is middle schooler.

            If an adult hasn’t gotten conservation of energy yet, (s)he is a moron and will never get it. Only adds noise, no signal.
            Worse, editors only see clicks and add views. HackADay morphs into ArtsAndCraftsADay. History!

          2. Haha,
            It’s possible to make use of a wind turbine on a moving vehicle without any problem with conservation of energy though – however only if there’s wind blowing. Test vehicles that just mechanically couple the wheels and the turbine have gone over double the wind speed when going directly up or down wind. And of course sailing exists.
            Doing it electrically mightn’t be as good, but in theory there’s a limited set of circumstances where it would technically work. It’s just not particularly practical sounding.

    2. While wind powered vehicles can move faster than the wind with a sufficient turbine, and aren’t perpetual motion machines, it does seem difficult compared to solar. They have to be able to transfer power both directions depending if they’re headed upwind or downwind, and that means a large size if you’re going to run continuously. (In one direction you thrust against the wind and in the other you operate as a regular turbine) I don’t know how crosswind will go, although I can guess that it will not work as well, unlike with sails.

      Also, if you’re much faster than the wind, then the dominant airspeed is barely different from the groundspeed, and so you get drag from the airspeed without being able to extract much power from a difference in speeds. You’ll probably want to be able to take down any such turbine when driving in low wind. Much like how it’s always solar and batteries rather than solar alone, the power density of an simple normal boxy vehicle that isn’t slow will generally be higher than the power that can be captured from its footprint at once.

  2. I found your build really nicely done, thank you for sharing. I particularly enjoyed the way you implemented the throttle control of two controllers. By the way I subscribed to your channel. Looking forward to your projects.
    Sincerely Greenerwheels.

  3. @Drew: putting the switches in the negative is a bad idea. When you turn it off the whole controller will be at 48V. If you have (now or in the future) some data / control signals going around the ~48V on that will fry your controller or monitoring device. Put the switches in series with the fuses, after the fuse.

  4. A most interesting build. I wish you lived near me Drew.
    $5000 Canadian? That’s actually not too bad. Do you have a manifest? Like where you got all your parts and batteries etc. along with cost of individual materials?

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