Live data from Hacker News

Toyota testing improved solar roof for EVs that can charge while driving

techcrunch.com

81–90 of 172 posts

Re: Toyota testing improved solar roof for EVs that can charge while driving

#81

This is interesting because the solar strip on the Nissan Leaf SL was just a do hickey, 9 watts max. It was capable of trickle charging the 12V starter which meant less draw for charging the 12V coming from the traction battery. Not nothing but really not much. I don't think it even rounded up to a mile of range. I'm not sure what's up with the visibility out the rear window of the Honda as pictured.

> It was capable of trickle charging the 12V starter

Enough to increase the utility of a rarely driven ICE car tenfold.

Re: Toyota testing improved solar roof for EVs that can charge while driving

#82

Earlier quoted context omitted.

2015 and later variants of the Prius already have this via the solar roof option: https://www.jpauleytoyota.com/blog/how-does-the-toyota-prius... “If you want to activate the solar powered ventilation system before you get out of the vehicle it is a simple process. On the left side of the steering column, you will find a small square button with a car and fan on it. Press this button before you turn off your vehicle…

I did not know that, and neither did the salesman when I was choosing my current car. They really should put that feature front and center, at least locally. Maybe that option isn't available in this market.

The salesman isn't there to be an expert on the car, he's there to be an expert on how to screw you on the contract.

It's one of the better things about Tesla, their sales people actually know the ins and outs of the cars because that is the only reason they are there.

Re: Toyota testing improved solar roof for EVs that can charge while driving

#83

I 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…

Tesla will keep your car at 105F or less while parked unless your battery is too low.

Re: Toyota testing improved solar roof for EVs that can charge while driving

#84
post #32
post #10

I'll start thinking Toyota is serious about EVs when it actually starts saying so -- only recently it said the future are hybrids . Yeah, right. Good luck with the bankruptcy/firesale in 10 years Toyota!

Hybrids are the future for most of the market worldwide. It will take decades to build out the charging infrastructure necessary to support battery electric vehicles. Some industrialized countries will move faster.

Not really, you just have to be creative and use the power lines that are already ubiquitous: https://www.zap-map.com/london-street-lights-converted-to-ev...

Cities LOVE electric cars, and they will do their best to encourage their use.

Re: Toyota testing improved solar roof for EVs that can charge while driving

#85
post #20

I 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…

Yeah I'd want that in a normal ICE car.

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?

Re: Toyota testing improved solar roof for EVs that can charge while driving

#86

Does the math check out? You would need about 10kW-h to get the claimed distance, times three for the efficiency (by the way, there are NO mass-produced cells with 34% efficiency; they must be using GaAs or multijunction cells to achieve 34%) means solar input of 30kW-h per day. The projected horizontal area of a Prius is 8m^2 (including the windows) so we need about 4 hours of 1000W/m^2 insolation. Which I guess isn…

And then you have to figure, if you took the $ and mass budget of the solar cells, could you just make the battery pack a little bigger/better instead for the same or more gain? Keep in mind the gain would be more reliable. You wouldn't have to depend on sunny days, and sunny parking spaces. You also have to ask if the $ spent on these solar panels might be better spent on your house, where they will never be in an i…

Not everyone has a garage, or can practically run a line out to the street. A self-charging car would be a good option for many. The charge this can manage is more than I drive, i’d Be very interested.

Re: Toyota testing improved solar roof for EVs that can charge while driving

#87

Earlier quoted context omitted.

I'm actually not sure in terms of car AC. Local wisdom says that on hot days your AC will sap up to 10 HP from your engine. Not sure how accurate that is. Looking around on Telsa forums and the like, I'm seeing numbers between 1 and 3 kW. My house's mini split AC unit draws around 9 amps (according to documentation, anyway), so around 2 kW. Actual numbers seem to be closer to 3 kW in the summer.

hmm, gets me wondering if that's why my car can't climb hills when on AC.

That may be part of it. Most (all?) newer cars will automatically cut off the AC pump under heavy acceleration.

Re: Toyota testing improved solar roof for EVs that can charge while driving

#88
post #60

Who wrote this? "This demo car’s prototype cells can convert solar energy at 34% and up" 34% what? "Using a redesigned solar battery cell film that measures only 0.03 mm" 0.03mm wide? Long? And what's a solar battery cell film???

The efficiency percentage on a solar panel refers to the amount of radiated energy from sunlight that can be converted into electricity. https://en.m.wikipedia.org/wiki/Solar_cell_efficiency

Less sure about the 0.03mm but I'm guessing the relevant metric would be thickness or depth.

Re: Toyota testing improved solar roof for EVs that can charge while driving

#89
post #78

Earlier quoted context omitted.

"Hang on, I'm hitting the turbo button." (turns off AC)

Every car with voice control should recognize “divert life support to propulsion" as a command to turn off engine-driven AC.

Oh man passenger reactions would be so awesome. Suddenly the driver just says "divert life support to propulsion" - and the passengers are like "WAIT WHAT LIFE SUPPORT?!"

Re: Toyota testing improved solar roof for EVs that can charge while driving

#90

They are claiming up to 27.7mi per day left in the sun. If true, my 5mi commute each way would be possible without ever charging the vehicle in the summer... That being s said, curious how this holds up to weather (hail, snow, etc) and whether those numbers are accurate.

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 it snows - which is all winter.

So it'd only be beneficial here during the summer, except when it's raining which is currently 3/7 days of the week.

I mean it'd be a nice bonus I guess, but at least for my situation it wouldn't make a ton of sense to spend extra on.

Post reply on HN