There's also Sono Motors, a start-up from Munich, Germany. They aim at delivering something they call a SEV (Solar Electric Vehicle) in 2020. They have an interesting concept and more than 10k reservations. https://sonomotors.com/?lang=en
Toyota testing improved solar roof for EVs that can charge while driving
121–130 of 172 posts
Re: Toyota testing improved solar roof for EVs that can charge while driving
#122Earlier quoted context omitted.
Wikipedia says 3kW https://en.wikipedia.org/wiki/Automobile_air_conditioning#Po... It also says that the most efficient photovoltaics yield 175W per square meter. (Though I've seen figures as high as 200W.) https://en.wikipedia.org/wiki/Solar_panel#Efficiencies
That's for a belt-driven A/C, tied directly to the engine RPM. They're inherently much less efficient because they have to work over a wide range of speeds. A motor-driven A/C will be 1-2 kW. That's also the peak power, and a motorized A/C will instead be turned on and off leading to a much lower power draw that also depends less on the peak power. Typically a 50-30% duty cycle, so 200-300 watts very roughly. More de…
And if instead of getting into a sweltering 330K car, if 300W was enough power to cool it to a reasonable 300K, that's still a win. Happy to start car to cool it down to a comfier 295K.
Re: Toyota testing improved solar roof for EVs that can charge while driving
#123Earlier quoted context omitted.
Why would you want this feature knowing that is burning gas that you paid for while idle? Would you be happy about the car releasing toxic gases like CO and NOX while parked?
Because of the “going to the emergency room twice with heat stroke” thing, I’d guess.
But it seems that "dying of CO poisoning while staying cool from the AC" would be worse?
Re: Toyota testing improved solar roof for EVs that can charge while driving
#124I once used an 85W portable solar panel to charge my battery while driving after the alternator failed.
It was surprisingly effective at keeping the car operable, at least until the sun went down. I didn't have any accessories running, so it was just the ECU/fuel pump/injectors/ignition it had to keep up with.
The experience left me wondering what MPG improvement it would be to embed solar cells in the trunk lid and hood for charging the battery in the daytime, offloading the alternator.
Re: Toyota testing improved solar roof for EVs that can charge while driving
#125Earlier quoted context omitted.
> The extended range is nice and all, but if somebody makes a car that can run the AC without running/draining the battery while it's parked, even if it's just a little to keep the car interior at 35°C or so, I would, without exaggeration, buy it the day it's released here. Tesla's dog mode does this. Draining the battery isn't really something to worry about; AC uses <300 watts over long periods (turns on and off at…
You can also just turn on the AC from your phone 10 minutes before you leave. Or, have it learn your schedule so it prepares your car for you before you go.
In hot climates, even when the air temperature returns to tolerable levels, radiant heat from the various surfaces is no joke.
Re: Toyota testing improved solar roof for EVs that can charge while driving
#126Always wanted this, makes a lot of sense in the desert. Is Toyota still turning on the headlights in the daytime? Seems like it would negate this advancement.
You mean DRL's? They lead to a significant reduction in crash rate - and since much of a car's carbon impact is tied up in the manufacturing of the car, that is likely a far greater impact than running the DRL's all day.
Plus, with LED DRL's becoming more common, the power drain is much less significant than the old incandescent lights. My old car ran the 55W headlights at around 40W each for DRL's. My new car has a DRL LED module that uses around 3W.
Re: Toyota testing improved solar roof for EVs that can charge while driving
#127The solar one of worked meant I do not have to charge the car for most of the trips I did!!! Shocking.
Re: Toyota testing improved solar roof for EVs that can charge while driving
#128I live in a pretty hot city (My car's outside thermometer showed 48°C yesterday at midday). The extended range is nice and all, but if somebody makes a car that can run the AC without running/draining the battery while it's parked, even if it's just a little to keep the car interior at 35°C or so, I would, without exaggeration, buy it the day it's released here. Hell, I'd consider it even if it would just keep the fa…
Electric car or not, a very low tech but effective approach is to use a decent sunshade. Quick to set up, and have been shown to lower the internal temperature 20 degrees or so.
Re: Toyota testing improved solar roof for EVs that can charge while driving
#129Earlier quoted context omitted.
Given the small surface area of the roofs, the efficiency of existing solar panels, and how much car companies exaggerate when it comes to miles (do they mean 27.7mi with all the seats removed, etc.) I would expect it to be a practical no-go for anything except sunshine. I'm from michigan, so in the winter assuming you park your car in the open for your job, you can easily expect it to be covered in snow - whenever i…
It would be very climate dependent. Here in Texas, typically I'd have 0 to 5 days per year with snow on my car. And nobody drives on those days anyway. And there are 228 sunny days in an average year. I would be worried about hail, though. I know a lot of people whose cars have been damaged or even totalled by hail.
Insurance companies here have worked out that they save money by cloud seeding outside of the cities to minimize hail damage in more populated areas.
Re: Toyota testing improved solar roof for EVs that can charge while driving
#130Always wanted this, makes a lot of sense in the desert. Is Toyota still turning on the headlights in the daytime? Seems like it would negate this advancement.
You mean DRL's? They lead to a significant reduction in crash rate - and since much of a car's carbon impact is tied up in the manufacturing of the car, that is likely a far greater impact than running the DRL's all day. Plus, with LED DRL's becoming more common, the power drain is much less significant than the old incandescent lights. My old car ran the 55W headlights at around 40W each for DRL's. My new car has a…
How'd you figure out the draw from your various headlights? Bulb specs?