Toyota Testing Improved Solar Roof For Electric Cars That Can Charge While Driving (techcrunch.com) 93
An anonymous reader quotes a report from TechCrunch: Toyota is testing a new and improved version of the solar power cells it previously launched on the Japan-exclusive Prius PHV, in a pilot along with partners Sharp and Japanese national research organization NEDO. This demo car's prototype cells can convert solar energy at 34% and up, which is much better than the existing commercial version's 22.5%. And, unlike its predecessor, it also can charge the car's driving battery while the car is actually moving, recouping significant range while the vehicle is in use. The new system will provide up to 44.5 km (27.7 miles) of additional range per day while parked and soaking up sun, and can add up to 56.3 km (35 miles) of power to both the driving system and the auxiliary power battery on board, which runs the AC, navigation and more.
Using a redesigned solar battery cell film that measures only 0.03 mm (that's 0.001 inches), the vehicle's engineers could put the film over a much broader surface area of the vehicle compared to the existing production version, with solar cells that wrap around covered body components, the rear door and the hood with relative ease. And as mentioned, the system can now work while the car is actually driving, thanks to changes in how generated power is fed to the system, which is a huge step up from the last generation, which could only push power to that auxiliary battery to run the radio, etc. when in motion. This new test vehicle will hit the road in Japan in late July, and perform trials across a range of different regions to test its abilities in different weather and driving conditions.
Using a redesigned solar battery cell film that measures only 0.03 mm (that's 0.001 inches), the vehicle's engineers could put the film over a much broader surface area of the vehicle compared to the existing production version, with solar cells that wrap around covered body components, the rear door and the hood with relative ease. And as mentioned, the system can now work while the car is actually driving, thanks to changes in how generated power is fed to the system, which is a huge step up from the last generation, which could only push power to that auxiliary battery to run the radio, etc. when in motion. This new test vehicle will hit the road in Japan in late July, and perform trials across a range of different regions to test its abilities in different weather and driving conditions.
Electric cars will be an environmental catastrophe (Score:1)
Horses are the future.
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Chevalines [technovelgy.com] to be specific.
Re:Electric cars will be an environmental catastro (Score:4, Interesting)
Horses for transportation were an environmental disaster.
https://www.historic-uk.com/Hi... [historic-uk.com]
This problem came to a head when in 1894, The Times newspaper predicted “In 50 years, every street in London will be buried under nine feet of manure.”
https://enviroliteracy.org/env... [enviroliteracy.org]
Benjamin Franklin complained in the late-eighteenth century of the “thundering of coaches, chariots, chaises, wagons, drays and the whole fraternity of noise” which assailed the ears of Philadelphians. Boston and New York both passed ordinances banning traffic from certain streets to protect hospitals and legislative chambers from the noise.
http://evworld.com/urban.cfm [evworld.com]
One contemporary British farmer calculated that each horse consumed the product of five acres of land, a footprint which could have produced enough to feed six to eight people. Probably 15 million acres were needed to feed the urban horse population at its zenith, an area about the size of West Virginia.
no, expensive (Score:2)
Horses are the future.
Not if PETA can stop it
Anyway, such cars will be so expensive that only rich elitists will be able to lease it: it won't ever be bought. Also, will it be driverless? If yeah, then such cars will mainly be used by the likes of Uber, not normal people
Re: no, expensive (Score:1)
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Re: Electric cars will be an environmental catastr (Score:1)
deploy it on solar arrays, not the car (Score:2, Informative)
800W was the output of the solar panels as quoted in the article (impressive for a small area), and a vehicle battery is, give it approx. 80kWh? That would take 100 hours of charging (~10 days sun) to charge full.
A nice contribution, but negligib
Re:deploy it on solar arrays, not the car (Score:4, Informative)
"The new system will provide up to 44.5 km (27.7 miles) of additional range per day while parked and soaking up sun, and can add up to 56.3 km (35 miles) of power to both the driving system and the auxiliary power battery on board, which runs the AC, navigation and more.".
Which is more than the average person drives in a day.
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*When parked on the equator during summer solstice.
This is going to be excellent! (Score:1)
This little car comes with 800W of solar power designed-in and built from the factory? Fuck yeah!
People living out of their cars will finally be able to legitimately charge their cell phones using their own electricity. They can download the latest porn to jack off to and eventually they can drive themselves to the next Wal-Mart parking lot when they inevitably get kicked out of the one they're currently staying at! All without using any expensive fossil fuels to speak of!
Re: This is going to be excellent! (Score:1)
I'm thinking what you're thinking - the driving range is a nicety but having 800W available for electronics is the bigger deal. Any car battery that can drive you 200 miles on a charge can probably keep a laptop running indefinitely as long as there's a few hours of peak sun to top it off every day. For tech heads this concept is appealing...drive out to buttfucking nowheresville, tether to phone, hit the VPN, all-day long work from anywhere there's a cell tower and some sun.
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Re: deploy it on solar arrays, not the car (Score:1)
How do you get from 45km to 1km?
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There is something wrong with the data here.
I think it probably adds 35 miles as long as those are down hill with a tail wind and your AC is switched to fan only level 1.
Solar is fine but hard to keep a car clean as well as most driving is not in the midday sun all day (We have these things called shadows, underground parking, etc.
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The real benefit is environmental control for the large battery - prolonging its service life.
Re:deploy it on solar arrays, not the car (Score:5, Insightful)
Much as I'm a supporter of EV technology, and while this is a nice development, one must confront the reality that cells on the top of the car roof or hood will *never* make much of a difference in driving range.
It provides up to 27.7 mi/day, while many EVs only do 100mi/charge and the gold standard is getting around 200mi/charge. That's a pretty big percentage. It will provide for most of most people's needs if it even gives two thirds of that.
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> while many EVs only do 100mi/charge and the gold standard is getting around 200mi/charge
You're a little out of date. *Most* EVs on the market today are rated 200+ miles. Premium options/models are up over 300 miles now. :)
=Smidge=
Re:deploy it on solar arrays, not the car (Score:4, Insightful)
An additional 15-30 miles/day isn't going to make a difference in the overall range.
But it will make a big difference in how frequently the car needs to charge (without solar cells). Most people don't drive 300-400 miles per day.
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It's not negligible. If you assume 12 hours of daylight per day, the solar panel recovers 8.3% of the vehicle's battery capacity per day. Right now I only refuel my car once a month, so with a car like this, I might never need to plug it in at all.
Re:deploy it on solar arrays, not the car (Score:4, Insightful)
The best real-world examples of highway capable EVs with integrated solar charging are the Sono Motors Sion [sonomotors.com] and the Lightyear One [lightyear.one].
The Sion bills itself as "up to" 34km of additional range per day.
The Lightyear One has a little estimator on their website based on your location. For me it'll get 18-44km per day depending on time of year.
This is small, but not negligible. Even going by your own figures, 800 watts is equivalent to about 3 miles of additional driving per hour of charging at that rate. That's not nothing, considering such a car could be spending literally all day in the sun while you're at work or whatever... 20+ miles of range per day is enough to cover a lot of people's daily needs.
That said I don't think it's really worth it, but if they can do it without compromising the rest of the vehicle or bloating the price too much, free (as in beer) energy is free energy.
By the way 80kWh is very much at the top end of things; Good job cherrypicking.
=Smidge=
OK, provided it is not a dark colour (Score:2)
Dark cars should be banned. Or at least have to pay more insurance. They are so hard to see.
So what we need is white or yellow solar cells that are easy to see while absorbing the light.
(Not entirely fanciful as I think most cells absorb in the ultraviolet.)
That said many years ago I knew someone that had solar cell on their aeroplane. Worked really well. It was a 1930's Tiger Moth that had no electrical system, and the cells were used to keep the radio battery charged.
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"So what we need is white or yellow solar cells that are easy to see while absorbing the light."
It exists. http://www.lofsolar.com/About-... [lofsolar.com]
"Not entirely fanciful as I think most cells absorb in the ultraviolet"
Photovoltaic cells are sensitive to incident sunlight with a wavelength above the band gap wavelength of the semiconducting material used manufacture them. Most cells are made from silicon. The solar cell wavelength for silicon is 1,110 nanometers. That's in the near infrared part of the spectrum. So
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They are so hard to see.
Huh? Hard to see when? Certainly not in rain or fog. Certainly not at night when all you can see is headlights. Please don't make up arbitrary silly statements. And while you may drive a monstertruck among European microcars 99.999% of people can't see the roofs of other cars making it completely irrelevant what colour the solar panels are.
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The problem with your assertion is that... all solar panels are black.
I think it might have something to do with absorbing light, whereas white reflects it more. That's why you wear white in the full sunlight on hot days.
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But if the car's round trip is less than the amount it charges each day, it will always be full. Then you start talking about charging stations in parking lots where the cars feed back to the grid.
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800W was the output of the solar panels as quoted in the article (impressive for a small area), and a vehicle battery is, give it approx. 80kWh? That would take 100 hours of charging (~10 days sun) to charge full.
So basically perfect then if you park your car outside and realise that many people don't actually drive the full range of a car in 10 days. I don't consider this a niche.
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Dude, stop and think for a change, just fucking once. So what difference will a solar panel make with a car with a flat battery, just waiting a day, to get to the charging point, that is simply too far to push the car and way, way cheaper than paying for a tow truck. Simply come back tomorrow and drive that 50 kilometres but sure, you can try pushing a car that far instead or be happy to pay for a tow truck. Solar panel for an EV is common sense, gees.
Again? (Score:2)
Cruising along a flat highway, you are expending 15-20 Kw. How much does the solar array provide - 4-500W on the best possible day at noon. In a practical situation (i.e. hills, slowing and accelerating), the extra weight of the cells and the charging method is going to be a wash.
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Even regular flexible solar cells [ebay.com] available today are lighter than a bag you might have in the car - let alone an additional passenger.
Weight is not an issue at all.
Hell... even charging while driving and efficiency are not an issue.
Back of an envelope calculation will tell you that should you jury-rig some old school roof solar panels to an electric car's roof and trunks that you are covered for most daily city driving.
Add weekends and we're in the territory of "fully charging only once per season... twice
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4-500W on the best possible day at noon.
Their claim is double that: 860W.
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Lil BOTE calculation tells me that a panel of these the size of what I currently manufacture would be about 510 watts under best conditions.
I wonder if I can get my boss to order a couple sample crates.
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General rule with solar power: Whatever the manufacturer claims, halve it.
The manufacturer claims are for a panel carefully positioned in optimal orientation. On a very cold day. With the atmosphere removed.
Re: Again? (Score:2)
Most of the time, cars donâ(TM)t move.
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I love backing up our Sprinter with the rear view camera. It's basically the cheapest camera available with the cheapest monitor that people said was worth buying. I have the brightness cranked way up, but everything has auto brightness/gain control, so I can always see. And because it's turned up, I can see clearly (like daylight) well after it starts getting visibly darker out. But I wish I'd spent more on the camera, not to get better quality, but just to get a hood. Backing through the gate where we liv
Time to go back to the classic (Score:2)
Make something like this
https://www.streetsideclassics... [streetsideclassics.com]
make it light, maybe a bit more boxy and cover it with solar panels. With the right trade-offs you could have a car that is actually practical in a sunny climate, especially for short commutes.
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On second thought, for drivers with short commutes just make a solar version of this
https://www.amazon.com/FirnFos... [amazon.com]
Futures (Score:1)
We think of hybrids as a halfway step to full battery-electric vehicles (BEV), but that doesn't mean BEV is the final endpoint.
Solar-assisted BEV and Solar-assisted Hybrid are among the most promising options for a post-BEV powertrain, for around the 2030's or so.
It's true that you only get like 2-3 horsepower direct from the sunlight, but if the car is parked all day in the sun, it builds up over time to an amount that still isn't enough to do 100% of your driving, but does cover maybe 30-50%. Which does
Does not compute (Score:5, Informative)
While sitting still, it provides an additional 22.5 km range.
While driving, it provides an additional 56.3 km range.
Say what? Something isn't right here. The first link in TFS is the somewhat more technical announcement from Toyota, and contains a hint of a suggestion for the testing / calculation schemes in the asterisks on the two numbers:
Maximum amount of charge generated by the solar charging system while the vehicle is parked or being driven, converted into travelling distance according to the JC08 Japan test cycle. Calculated based on the Japan Photovoltaic Energy Association Labeling Guidelines (FY2016), taking into account the various losses incurred in onboard systems. Solar radiation amount calculated based on the daily data of the average year between 1990 and 2009 in the Nagoya district (source: NEDO).
Ah, the "various losses incurred in onboard systems" -- in other words when the car is sitting still, the solar panel is charging the battery, which is not 100% efficient, and then driving some time later discharges the battery, which is also not 100% efficient. But, when driving the solar panel's output is being sent directly to the power bus to drive the wheels and accessories, bypassing the charge/discharge inefficiency.
And for a moment, I thought it was backwards day!
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I wondered that myself. Thx for RTFA.
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Its not charging while driving... full stop.
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That still doesn't compute. I highly doubt the charging / discharging system contributes to a 50% energy loss. That would make it 1960s era battery technology.
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That still doesn't compute. I highly doubt the charging / discharging system contributes to a 50% energy loss. That would make it 1960s era battery technology.
The panels may be a bit more efficient when the vehicle is moving, because the flowing air will keep them cool. PV efficiency declines as the panels get hotter. That still doesn't explain the discrepancy, but it might close the gap a bit.
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GP post misread the numbers -- it's 44.5 km of range per day while stationary. (The 22.5 is from the 22.5% efficiency of the solar panels originally on the car they modded to make this demo car.)
This works out to 21% losses in the charge/discharge system, which is a lot more realistic. It roughly matches the values in Table 6 of this paper [sciencedirect.com] I found, especially at the low charge rates that these solar panels will result in.
Lightyear 1 (Score:2)
Interesting that this announcement from Toyota follows so closely on the tail of the announcement of the Lightspeed 1 prototype.
https://www.theverge.com/platf... [theverge.com]
It is the exact same concept, except Lightspeed is coming from a team that started with pure solar race cars and worked their way backwards to a body that's aero and able to hold a lot more cells than Toyota's. 5 m^2 and 1.25 kw maximum output.
They claim up to 12 km/hr peak solar charge rate. They even have a calculator on their website that lets yo
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Oops, forgot the calculator link.
https://lightyear.one/ [lightyear.one]
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TANSTAAFL. These cars are THREE TIMES the launch price of the Toyota Miral and the Tesla Model S (both around $55,000, while this is $150.000).
They've also cut the size of the electric motors to make that range happen (larger motor = more friction losses), so it accelerates 0-60 in TEN SECONDS. By comparison, the Tesla Model S from 201 can do 5.6 sec, and the Toyota Miral can do 8.9.
So, even compared to other first-generation EVs of iit's class, the thing comes out horribly overpriced, and underperforming
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Found the non-engineer.
to garage or not to garage (Score:2)
Charge while driving? (Score:2)
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If your commute is at 70 miles per hour, it's not a *typical* one. ICE vehicles are going to rule long distance highway travel for some time, which is their optimal use-case.
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if there was no atmosphere it'd generate about 1.1 kilowatt. ... (Last I checked only about 100W actually makes it to the ground.)
At Earth's average orbital distance the intensity of sunlight with no atmosphere is 1,368 watts. At ground level that is reduced to about 1000 watts. These solar cells are very advanced models, 34% or better, and thus could generate 340 watts. Do you live in the Aleutian Islands?
This is technically untrue! (Score:2)
The only way you're 'recharging your car while you drive' with solar panels on the roof of the vehicle is if the solar panels' output is higher than the power required to operate the vehicle! At best you're reducing the drain on the batteries by a small amount, and at best you're trickle-charging the batteries when the car is parked.
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Isn't that what the summary says, or at least strongly implies? That's certainly how I read it. I don't think the average person would read this and expect the car to be generating more energy than it's using. I think it's fairly obvious that the point is to help top up the normal charging process, not to replace it.
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Furthermore here's a quote from TFA:
In addition to substantially boosting its power generation output, the demo car employs a system that charges the driving battery while the vehicle is parked and also while it's being driven..
It's misleading and technically inaccurate. You can't 'charge the battery' while you're drawing more current from it than you're putting in. At best it reduces the discharge rate by a little bit.
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A/C power (Score:2)
You will probably spend the extra energy in cooling the car after sitting in the sun.
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In the meanwhile, what's the deal with Tesla's vampire drain? https://teslamotorsclub.com/tm... [teslamotorsclub.com] - maybe Tesla cars should be more like iPads, you can charge them and they lose a fraction of 1% per day.
Also, the big deal with a rooftop charger is not the extra range directly, but the fact that on the road, sun implies both some energy creation and the use of air conditioner. The glass ceiling of Teslas feels stupid in comparison, as it directly lets in sunshine, which is going to heat the passenger compartme
Verify first... (Score:1)