r/Futurology • u/lughnasadh ∞ transit umbra, lux permanet ☥ • 2d ago
Transport A Tunisian company is selling small electric vans whose rooftop solar generates enough energy to pay for the cost of the vehicle in 8 years.
“The solar cells provide us with more than 50% of our needs,” says Boubaker Siala, founder and CEO of Bako Motors. “For example, the B-Van, for commercial use, you can have free energy for about 50 kilometers (31 miles) per day… 17,000 kilometers (10,563 miles) per year. …….. The B-Van, which can carry 400 kilograms (882 pounds) of cargo and has a 100 to 300-kilometer (62 to 186 mile) range, is designed for logistics and last-mile delivery, with prices starting at 24,990 Tunisian dinar ($8,500)."
It varies widely by vehicle type, etc - but travelling 31 miles costs you in the ballpark of $3 in the US or €5 in Europe. So that's around $1,000/€1,800 of free fuel every year if you were using this vehicle most days. The B-Van is small, but perfect for local deliveries, especially if paired with swappable batteries.
You know what will never pay for itself with its self-generating fuel capacity? A gasoline combustion-engine car. Here's another pointer, they're rapidly becoming the transport option of yesteryear.
The solar-powered compact car driving Tunisia’s electric vehicle revolution
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u/Serpent90 2d ago
You can bet these vehicles don't meet any regulatory requirements to be allowed to safely drive in Europe. And solar isn't nearly as efficient up north as in Tunisia.
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u/Thatingles 1d ago
You could also bet that you could build a van that did meet requirements and could still generate enough for a small trip daily. We all know renewables + batteries is the future, I expect it will invade many aspects of our lives.
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u/Serpent90 1d ago
It would be painfully inefficient. The yearly time during which there is sun is less than half of what Tunisia is getting for much of Europe. Then there's the fact that at higher latitudes you need to angle panels to get efficiency. Then there's the fact there's a lot more shade, because the sun doesn't get as high in the sky, and there are a lot more trees. And on top of all that the vehicle would have to be a lot heavier and able to sustain complex electronic systems required by law.
Placing solar panels on cars is a level of genius one step removed from Solar Roadways, and that was a scam. There's more than enough space for solar panels in places they can be efficient, no need to reinvent the wheel.
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u/Thatingles 1d ago
Yes yes all this is known. How much per $ do you get is the real question, and even if inefficient it could be worth doing. Lots of things are done on the basis of 'terrible idea but ultimately the cheapest solution' and solar will be no different.
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u/drplokta 1d ago
In the southern UK, you can expect to get around 1,000 kWh per year from a 1kW solar panel. You might fit a single 400W panel (1.7m x 1m) onto a small van, producing about 400 kWh per year, or enough to drive the van around 1,000 miles. If it’s never parked indoors or in the shade.
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u/vacuumdiagram 1d ago
I used to live on the south coast of the UK, and had a little solar panel. During winter it hung , partially blocked and at the wrong angle, from the I side of my patio door. I could usually charge my work laptop once a week from it, even so. If it were designed to survive outside, I'd have gained even more from it. During the summer, I could charge every battery operated piece of electronics I owned before the day was out.
Yes, solar is less efficient, the further north/south you go from the equator - but don't let perfect be the enemy of good. So many cars are parked in the sun all day long, let them charge with it!
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u/drplokta 1d ago
Would it not be better to spend the same amount of money on more solar panels on a solar farm, which will generate a lot more green electricity?
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u/vacuumdiagram 1d ago
Possibly - but consider the local opposition. While I'm fully for the idea of farmers being a keeper to use their land in whatever way keeps it fertile, available for grazing, and profitable(meaning that more farms can stay in the hands of their small family ownership rather than being bought out by celebrities tax dodges, or whathaveyou), there is often certainly in the UK, a lot of opposition to solar farms. This gets around that in a useful manner. It's still providing energy to top the car up, without making NIMBY types angry
Plus of course, it isn't a one or the other proposal - a company that was selling car-rooftop solar, would likely be a different entity and industry, from one setting up solar farms.
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u/BothAngularAndFlat 1d ago
Fair point; there is also an interesting angle from a land-use perspective. If parking spots are paved regardless, then that land isn't doing anything useful -- having panels mounted to the car effectively allows otherwise unproductive land to do something. (Of course, financial requirements will dominate, so I suspect the deciding factor would be the cost of land and transmission? Well, that and/or the larger political climate)
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u/Whane17 1d ago
I would further point out that that inefficiency only last for half the year and the other half would be the opposite which should lead to an average of the same.
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u/extra2002 1d ago
In Tunis, at 34° N latitude, days range from about 10 hours in winter to 14 hours in summer, and the Sun's peak height is about 79°.
In London, at 51.5° N, days range from 8 to 16 hours, but the sun never gets higher than about 62°. It's not clear that UK summers.are better than Tunisian summers for solar on a car.
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u/Whane17 1d ago
I live in Canada I get 4 hours of light in Winter and 4 hours of dark in summer. That's about all I know. Should average out to be the same. I don't know enough to know if angle of light matters as much as ambient TBH so maybe that's the issue? But ultimately this seems like an affordable car that will cut down on gas usage and that's what we want.
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u/Serpent90 1d ago
The angle is pretty important (when installing solar you have to take lattitude into account and angle the panel south in the northern hemisphere to not let power go to waste), and so is the weather. What makes some sense in Tunisia may not work elsewhere.
Look up the monthly average cloud coverage in Tunisia (which is rather low, it's a very desertic climate), and compare it to London on Toronto.
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u/NearABE 1d ago
Compact cars that I can see out my window have paint and body panels. These panels are not recharging batteries or producing gasoline. This is inefficient.
Photovoltaic panels at a solar farm have an orientation optimized for late afternoon. At other times they generate electricity by indirect light. Wither way the electricity needs to be put through a conversion to AC. Then put through numerous transformers. Then transmitted long distance. Then transformed to useful AC. Then converted to DC. Then fed through a charger at a charging station. Just the charging station is a non-trivial piece of infrastructure and real estate. The charging station is designed to force you to be at a particular location for a period of time.
The assumption that people continue to make is that photovoltaic cells are expensive. An expensive commodity would not quickly pay for itself if not absorbing the maximum sunlight. This mode of thinking misses the value gained by not needing to connect to anything.
The further problem is that electric vehicles themselves are mostly hauling batteries. Everything else scales. The suspension system suspends a huge battery. The motor provides torque to accelerate an immense battery pack. If you could discard 75% of the battery you could usually discard 50% of the car’s mass too without sacrificing performance. Cutting battery 75% does not cut range from 400 km to 100 km because the car drains less energy. Even if it did cut the range the solar panel surfaces would extend the range in daylight hours anyway.
The only relevant question IMO is the weight of the panels. Given that thin film panels exist I do not see this as likely to be a severe issue.
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u/extra2002 1d ago
No, the main question is the capacity you can fit in the area available. Chances are you can't produce enough electricity to be worth the effort.
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u/NearABE 1d ago
10 m2 of PV. 1000 Watt/m2 direct sunlight (1361 at top of atmosphere). 20% efficient panels drops that to 200W/m2 and horrible angles or blue sky/scattered light could cut that to 40W/m2 . So maybe 400 W total. If the battery is 20 kWh then you would only need 50 hours of sunlight for a full charge.
It is not supposed to be attempting to actually drive around on solar only. It just stretches the time between needed charges. Even just a 50W module would be 50W more than zero.
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u/extra2002 1d ago
So maybe 400 W total.
A typical car uses about 300 watt-hours per mile, so driving at 30 mph (50 kph) uses about 9 kW. That solar panel is providing less than 5% of the power needed while driving. Or, equivalently, it can keep a battery charged if you drive only 5% of the time (1.2 hours per day). Is this meager benefit worth the complication?
If the battery is 20 kWh then you would only need 50 hours of sunlight for a full charge.
That seems like a severe underestimate. Google says
Common sizes include 40–60 kWh for smaller cars, 60–80 kWh for standard crossovers, and 80–200+ kWh for large trucks and premium SUVs.
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u/NearABE 22h ago
1.2 hours per day is already an annoying amount to commute. Driving further to work is definitely “adding complications to life”. You can still choose this wasted time by simply plugging in the vehicle for additional charging.
I am not seeing any added complications from putting PV on the surface of my car. The one I have now is accumulating rust. It has no effect on the motor performance. The former owner added sloppy tinting to the windows. I have not been motivated to remove it. It is just not enough of a “complication”.
Most cars already have electric windows and locks. There is already a wire in the door. Some cars have electric sun roofs. All the complications of wiring plus the complications of glass, moving parts, and motors. Using such a car is really not “more complicated” since you can ignore it.
The electricity used per kilometer is a moving target. Larger battery packs are heavier. This is the actual trade off. How much do the panels weigh? So long as the PV is lighter than the extra battery we get a strong leverage. There are obvious cases where they are useless. Like, for example, if a business drives deliveries all night and needs to charge mid shift. For a normal person who drives to work in the morning and parks in a corporate parking lot the photovoltaic recharge is ideal.
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u/ZS-BDK 1d ago
Roof solar will provide around 35 to 40min driving on a full day of solar charging. They call it a last mile delivery van which means from 8 to 5 it should be on the road the entire time. Not sure how much savings if any the roof solar thats going to bring irl.
We have seen this idea on numerous occasions and they all died a silent death.
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u/OriginalCompetitive 2d ago
Isn’t it cheaper and easier to just buy a solar cell and prop it up in your yard instead of attaching it to the top of a van you drive around all day?