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t1_jbjjjps wrote

>It's an absolutely absurd marketing gimmick.

Doesn't matter, now that the majority accept climate change is an issue the car manufactures have to invent and push the idea that "cars are part of the solution".

Expect a lot of these stories in the coming years and very little challenge to the viability of the ideas in them.

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t1_jbjp1f0 wrote

If some boffin manages to create a car that can entirely create its energy from photosynthesis then suddenly it drives converting CO2 to oxygen.

That I would hail a breakthrough miracle.

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t1_jbjx87h wrote

The problem is that moving a big thing fast and for long distances is energy intensive. So solar power is just not enough if you are expecting it to be self contained on a personal vehicle.

More to your point though, photosynthesis is an energy capture mechanism. In order to derive mechanical energy from the molecules produced (sugar and oxygen) the car would then need to react the sugar with oxygen. So in effect, you'd just be making a bad solar panel with extra steps.

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t1_jbjyxbk wrote

Thinking about the maths of it, I reckon a car with current level solar panels built into the roof would be a serious suppliment to the energy required.

I'm in the north of England and the 2.5kW, suboptimal panels on my roof generate about 15kWh on a sunny day.

Going by the size of the panel, I reckon at leat 1kW of capacity could be embedded on the average car roof, boot and bonet.

So a sunny day would then provide 5-6kW. So that's like 15-20 miles of driving?

Obviously the car would need external energy for the most part, but I don't think that's an insignificant amount of energy. And considering a concern for electric cars is still range and availability of charge points, knowing that you can get free mileage just by parking in an unshaded location for a few hours would be a big selling point to me.

I imagine the electrics of it are the most difficult part though.

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t1_jbk203p wrote

For a super efficient car your math seems about right. A gallon (~4L) of gasoline is roughly 33kW/h of energy, so 100-120 miles per gallon equivalent car is possible, but difficult (sorry for US units, that's how we measure car efficiency).

It may be good as a supplement like you said, or can possibly keep the AC running or something like that.

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t1_jbk7kzx wrote

Just so you know, when it comes to car efficiency the UK uses miles per gallon. Petrol stations however show prices by the litre, oh and we use miles and yards for distance.

TlDR: mpg is fine to use with us.

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t1_jbk8xai wrote

Yeah I went off Google's estimate of electric cars tend to get 3-4 miles per kWh (which I guess will actually vary massively)

And the car panel will be less optimal as the panels will be flat. Although unlike roof panels you could potentially move the car around to stay in the sun for longer.

For me, this would actually be an ideal car. I need a car for where I live, but I only use it a couple of times a week and almost always journeys of 5-6 miles or less. I'd only need to charge the car from mains in the depths of winter!

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t1_jbkvesv wrote

The amount of energy generated is lower than the loss of efficiency due to the added weight of a solar panel. It’s significantly more efficient to mount a solar panel on top of a pole wherever you spend the most time parked (house for personal vehicle, office for business vehicle).

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t1_jbm65ts wrote

Hmm, going by Googling the weight of a Tesla (1600 - 2000kg), and going by the 100W camping solar panel I have that ways 3kg...

I could maybe fit 6 of these rectangles on the roof of a car, so 18kg for 600W. 600W would generate 3kWh/sunny day.

So we've increased the weight by 1%, and get about 5% extra range per sunny day.

Seems like a decent trade off? You could probably even offset the weight by reducing battery size a little, as you need to carry less charge if you can top up power as you go?

Self charging from solar allays the fear that if you can't charge your car you won't be completely stranded. Fitting solar charging stations everywhere is a different use case really.

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t1_jbk8dey wrote

Solar(+battery) at home and charge there. That's where things are going for charging completely green in the near future as grids get greener every day.

On the road, batteries at the site of the charger that refill passively when not in use, supplemented by grid power when needed.

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t1_jbnpam5 wrote

Have two batteries, one at home being trickle charged by solar panels and one in the car being used. Make battery swapping easy to do and just swap them every night.

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t1_jbo7ipa wrote

That wouldn’t be viable for the same reason that animals don’t have chloroplasts. It would take more energy to carry them around than they could possibly produce, which is why plants are sedentary.

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t1_jbjtoy2 wrote

>"cars are part of the solution"

I mean zero carbon emitting cars are at least a part of the solution. Personal vehicles are far too efficient for many applications to ever be fully replaced. On top of that the world isn't going to perform 50 years-worth of public transport infrastructure construction in the next 10 years.

So yeah, electric cars / trucks are one part of the sustainable future we want to target (of course the smaller part of it they are the easier some things like city management, waste management etc. become).

It's just that this gimmick solution in the article makes no sense.

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t1_jbjvljo wrote

I don't think it's meant to be a sellable product, the undergrads built something for a resume. It got attention and some big company will hire them now.

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t1_jbkrnxr wrote

Yes, "marketing" was a poor word implying this will be for sale. It is however, as you stated, promotion of the university and the team.

While the project as a whole, the materials design and the car as a whole is absolutely fantastic, the carbon filtration part is a deliberate promotional gimmick that has no other academic or pratical purpose.

The statement by the team lead from the article: "We are cleaning the air while driving" and the fact that they put the filters in the car, most likely knowing they are just making it less efficient points to the idea that it was something done to catch attention (and was obviously successful to some degree). That is, of course, both an understandable and often necessary thing to do to promote the university etc.

I just wanted to remark on how pointless of an addition to the project car it is.

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t1_jbki6vw wrote

It's not a bad idea for short distance driving. Even if it takes 2-3 Years to remove a Tree's worth of carbon, it is a valid technology to look at.

It is not the solution, not the magic bandaid. But it's a tool and to scoff at it doesn't help the problem when we're supposedly already past a point of no return.

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t1_jbke6p3 wrote

Yup. Makes me think of a ad that comes on the radio. Boils down to "our hybrid car uses 40% less gas", well yeah of course it does because 40% of it's power comes from the electric motor, so your car isn't technically better. Know what reduces gas usage by an even bigger amount? Not having the car in the first place.

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