If electric vehicles are for saving the earth, why don’t all of the EV’s come with a solar panel charging system made onto the vehicle. A lot of vehicles would never need to be plugged in for a recharge.
Zrxkaw
Because especially in the UK you would be lucky to put more than 10 miles a day into a car that would have to be sat in the full sun all day
Because they would need a new battery every six months, made from Kryptonite mined by 3 year olds in Guatemala, unless they burst into flames spontaneously when you were stranded on the highway in the snow…….that’s why.
Answering for some friends.
Answering for some friends.
Solar panels on EVs are dumb for lots of reasons:
1) The area of an EV isn’t big enough to generate any meaningful power. You be lucky to fit 1kWp and that’d take 80-100hrs of bright sunshine to fill the biggest EV battery.
2) EVs aren’t usually parked in the sun, they’re shaded by trees, buildings, or parked in garages, while the sun is shining.
3) Solar panels would add weight and complexity to the EV.
This idea comes up over and over from people who haven’t really thought it through. You even see it on EVs from time to time as an astonishingly expensive cost-option.
Put the panels on the roof of your house!
(I’ve said many times that all new homes should be required to have 1kWp of solar and 2.4kWh of battery per bedroom.)
1) The area of an EV isn’t big enough to generate any meaningful power. You be lucky to fit 1kWp and that’d take 80-100hrs of bright sunshine to fill the biggest EV battery.
2) EVs aren’t usually parked in the sun, they’re shaded by trees, buildings, or parked in garages, while the sun is shining.
3) Solar panels would add weight and complexity to the EV.
This idea comes up over and over from people who haven’t really thought it through. You even see it on EVs from time to time as an astonishingly expensive cost-option.
Put the panels on the roof of your house!
(I’ve said many times that all new homes should be required to have 1kWp of solar and 2.4kWh of battery per bedroom.)
Speaking as somebody who owns an EV with 2 solar panels on its roof, (Hyundai Ioniq 5 P45) I can say overall it has mostly been a gimmick. I think they are 205W. Make no mistake, it does generate electricity for the car. Over its first year,it generated 73 kWh which funnily enough is the same size as the car battery.
Even when stationary it can help to top up the 12v, and charges the traction battery when out in the sun of course, so no flat battery for me in 23,000 miles so far.
It is “cool” though.
Even on the longest day of the year or a very sunny day can add only 1-2% of traction battery charge. In the UK, not much help then!
But personally I would have preferred a lovely big panoramic roof.
Even when stationary it can help to top up the 12v, and charges the traction battery when out in the sun of course, so no flat battery for me in 23,000 miles so far.
It is “cool” though.
Even on the longest day of the year or a very sunny day can add only 1-2% of traction battery charge. In the UK, not much help then!
But personally I would have preferred a lovely big panoramic roof.
I’ve heard claims that pano roofs increase range because on those rare cold-but-sunny days the roof reduces the power consumed heating the cabin.
Frist time poster comes trolling to see how we stumble over each other in pros and cons.
Nothing to see here, move on....
Nothing to see here, move on....
This concept is up there with that other classic question " Why don't they fit a wind turbine to the front of EVs so that they charge themselves as they drive along?"
...because to have any significant contribution the area needed is about as large as a lorry. Even if every surface of an EV would be solar panel it would mean nothing compared to the need.
The OP has a good point.
One day, someone will figure out a way to make small, light solar panels that are capable of filling an EV battery at 350kW or more.
Until then, I also have a P45 with solar on the roof, can confirm it is a gimmick, and, given the choice I would have gone for a pano roof instead.
One day, someone will figure out a way to make small, light solar panels that are capable of filling an EV battery at 350kW or more.
Until then, I also have a P45 with solar on the roof, can confirm it is a gimmick, and, given the choice I would have gone for a pano roof instead.
@Zrxkaw Audi A8 had solar sunroof 20 years ago for powering the climate control even after the engine had been switched off.
Toyota had a solar roof fitted to the Prius plug in hybrid from 2017. Here is one real world review. I suspect with an EV, a stronger energy regen system would be preferable to the low levels of energy captured from a solar roof.
"Toyota says the solar roof can add up to three miles per day, so I was keen to assess whether this might be true only in Death Valley. During my week with the car, in late April in the South of England, the weather varied from heavy overcast to bright spring sunshine, and I saw an average of two miles a day added to the car’s battery range prediction."
Toyota in Japan did do a trial in 2019 of solar panels everywhere with a Prius plug in hybrid, but I can't find any info on the results of the trial.
"By enhancing the solar battery panel's efficiency and expanding its onboard area, Toyota was able to achieve a rated power generation output of around 860 W*4, which is approximately 4.8-times higher in comparison with the commercial model Prius PHV (equipped with a solar charging system). 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, a development that is expected to lead to considerable improvements in electric-powered cruising range and fuel efficiency."
I wonder if solar panels all over the top surface of the car (even if they would add significant amounts of energy every day) were not commercially viable, principally because of the increase in costs for insurers to repair/replace body panels that have solar panels as part of the car's design?
One article claimed, Toyota is to start public road trials later this month of a Prius plug-in hybrid equipped with solar panels which could generate enough electricity per day to power the car for 35 miles.
Toyota had a solar roof fitted to the Prius plug in hybrid from 2017. Here is one real world review. I suspect with an EV, a stronger energy regen system would be preferable to the low levels of energy captured from a solar roof.
"Toyota says the solar roof can add up to three miles per day, so I was keen to assess whether this might be true only in Death Valley. During my week with the car, in late April in the South of England, the weather varied from heavy overcast to bright spring sunshine, and I saw an average of two miles a day added to the car’s battery range prediction."
Toyota in Japan did do a trial in 2019 of solar panels everywhere with a Prius plug in hybrid, but I can't find any info on the results of the trial.
"By enhancing the solar battery panel's efficiency and expanding its onboard area, Toyota was able to achieve a rated power generation output of around 860 W*4, which is approximately 4.8-times higher in comparison with the commercial model Prius PHV (equipped with a solar charging system). 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, a development that is expected to lead to considerable improvements in electric-powered cruising range and fuel efficiency."
I wonder if solar panels all over the top surface of the car (even if they would add significant amounts of energy every day) were not commercially viable, principally because of the increase in costs for insurers to repair/replace body panels that have solar panels as part of the car's design?
One article claimed, Toyota is to start public road trials later this month of a Prius plug-in hybrid equipped with solar panels which could generate enough electricity per day to power the car for 35 miles.
Minimal additional range capacity for the size of the roof (no more than 400W nominal capacity panel on a standard roof)
More added weight for the panels, and for the inverter necessary to convert and move the PV energy into the battery (the panels produce 12V energy, which is only good for the 12V 'standard' car battery, not the main battery
Panels would be flat on the roof, whereas they are tilted on a house roof or frame to make better use of the incoming solar (less efficient when flat, so that 400W is now going to be greatly reduced)
So on a really nice day in summer, with the car being parked in perfect sunshine for 10 hours, it's probably 'make' 2-3kW of energy. Or 10-12 miles of range at best. And you've got to lug that extra weight (and reduction in range) around with you all the time, on cloudy days, in winter, etc
So the 'never plugged in for a recharge' that you claim is rather a long way from being accurate.
More added weight for the panels, and for the inverter necessary to convert and move the PV energy into the battery (the panels produce 12V energy, which is only good for the 12V 'standard' car battery, not the main battery
Panels would be flat on the roof, whereas they are tilted on a house roof or frame to make better use of the incoming solar (less efficient when flat, so that 400W is now going to be greatly reduced)
So on a really nice day in summer, with the car being parked in perfect sunshine for 10 hours, it's probably 'make' 2-3kW of energy. Or 10-12 miles of range at best. And you've got to lug that extra weight (and reduction in range) around with you all the time, on cloudy days, in winter, etc
So the 'never plugged in for a recharge' that you claim is rather a long way from being accurate.
@Zrxkaw Octopus have asked the question last month
"How long would it take to charge an electric car with solar panels?
Given the number of solar panels a car could comfortably fit, the maximum amount of energy it could generate would be around 50 to 150 watts. To put it in perspective, that’s about the same energy needed to power one light bulb (definitely not enough to power a car!)
A standard 240-volt home charge point takes about an hour to provide enough charge to travel 30 miles. This compares to about two miles per hour if you were to charge up using only inbuilt car solar panels. For an average 300-mile range car this means it would take about 90 hours of direct sunlight to fully charge your car. When you consider your car might spend some time in a sheltered garage overnight or in the shade, in real-world conditions it’s likely to be even longer."
Although the article does point to a possibly different future, so never say never -->
"Perhaps one of the most exciting advances being released this year is the Lightyear 0. The Dutch designers behind Lightyear promise the Lightyear 0 will be the world’s first solar-powered vehicle.
With five square metres of more efficient solar panels, the company claims the car can be largely powered by the sun, only needing to be plugged in to recharge once every couple of months.
Although with only 7.5 miles of solar charge per hour this is still to be tested in the real world, and in less sunny climates.
The first Lightyear 0 is set to be on the road later this year and, if the claims are true, could pave the way for more solar-powered vehicles in future."
"How long would it take to charge an electric car with solar panels?
Given the number of solar panels a car could comfortably fit, the maximum amount of energy it could generate would be around 50 to 150 watts. To put it in perspective, that’s about the same energy needed to power one light bulb (definitely not enough to power a car!)
A standard 240-volt home charge point takes about an hour to provide enough charge to travel 30 miles. This compares to about two miles per hour if you were to charge up using only inbuilt car solar panels. For an average 300-mile range car this means it would take about 90 hours of direct sunlight to fully charge your car. When you consider your car might spend some time in a sheltered garage overnight or in the shade, in real-world conditions it’s likely to be even longer."
Although the article does point to a possibly different future, so never say never -->
"Perhaps one of the most exciting advances being released this year is the Lightyear 0. The Dutch designers behind Lightyear promise the Lightyear 0 will be the world’s first solar-powered vehicle.
With five square metres of more efficient solar panels, the company claims the car can be largely powered by the sun, only needing to be plugged in to recharge once every couple of months.
Although with only 7.5 miles of solar charge per hour this is still to be tested in the real world, and in less sunny climates.
The first Lightyear 0 is set to be on the road later this year and, if the claims are true, could pave the way for more solar-powered vehicles in future."
For conventional design the maths are unlikely to add up to useful.
Lightyear had a design targeting high efficiency and managed to get 5sqm of solar cells onto their car. Enough even in the UK to add significant range in summer given how few miles some cars drive.
The generated power in the UK would never be enough to mean you don’t have to charge bar some bizarre edge cases. But charging less often is definitely a possibility especially if you have a very efficient car design with a large panel area. And of course not everyone lives at our northerly latitude. The maths are going to be somewhat better for Southern California for example.
Then we may also have to recalibrate if any of the higher efficiency solar technologies get to commercial production. 40% efficient cells would also help the maths considerably.
Lightyear had a design targeting high efficiency and managed to get 5sqm of solar cells onto their car. Enough even in the UK to add significant range in summer given how few miles some cars drive.
The generated power in the UK would never be enough to mean you don’t have to charge bar some bizarre edge cases. But charging less often is definitely a possibility especially if you have a very efficient car design with a large panel area. And of course not everyone lives at our northerly latitude. The maths are going to be somewhat better for Southern California for example.
Then we may also have to recalibrate if any of the higher efficiency solar technologies get to commercial production. 40% efficient cells would also help the maths considerably.
Given that we often see threads about strange issues which turn out to be caused by flat 12v batteries, there must be a case to be made for a compact solar panel just to keep the 12v battery charged?
The obvious thing to do is have a section of the dash which holds a couple of panels.
One to top up the 12v and another user option to top up a different smaller battery for powering dashcams from.
Anything else is huge, weighty or expensive and not worth having in most places.
Gaz
One to top up the 12v and another user option to top up a different smaller battery for powering dashcams from.
Anything else is huge, weighty or expensive and not worth having in most places.
Gaz
These answers are very UK focused, for many people who live from Spain to South Africa the technology can be very different. They really don't need most of the gimmicks we desire.
www.c-fee.com
Solar TUK TUK
www.c-fee.com
I had a solar panel on my car 30 years ago.
Good it was.
I still have it in my shed but the rubber suckers have gone hard.
The thing is, with so many potential 12v issues for EVs or any car where short journeys are the norm it makes more sense to have that sort of thing built in to trickle charge now than it ever did before.
Gaz
Good it was.
I still have it in my shed but the rubber suckers have gone hard.
The thing is, with so many potential 12v issues for EVs or any car where short journeys are the norm it makes more sense to have that sort of thing built in to trickle charge now than it ever did before.
Gaz
They now have glass which acts as a solar panel and in fact can produce power at night.
So if all the car glass was made from that with minimal extra weight and it only topped up by an amount which took an entire year to pay for itself it would be worthwhile even if it meant the difference between limping home in turnip mode or getting home in turtle mode just the once whilst owning the car.
Gaz
So if all the car glass was made from that with minimal extra weight and it only topped up by an amount which took an entire year to pay for itself it would be worthwhile even if it meant the difference between limping home in turnip mode or getting home in turtle mode just the once whilst owning the car.
Gaz
The forthcoming Xbus will have integrated solar panels, and claims it can add up to 200km per day just by solar. It may be ultra-lightweight but it's a case of seeing to be believed...
I thought it was a legitimate question. You guys seem to have all the answers and some make sense. I didn’t realize solar panels were so heavy.
Sure you’re right the maths is questionable particularly for the UK and the cars we drive today. But electric Tuk Tuks in sunny parts of the world require less energy to move them and they get much more sun… it’s different maths in the end.
FWIW I’d buy a Lightyear if it were affordable/ available but not because of the solar panels. I’d buy for the efficiency. A car that partly refuels itself on sunny days is an occasional bonus, but the efficiency would be a benefit every day.
OTH if I lived elsewhere let’s say Sri Lanka, I might well take more interest in something like a solar tuk tuk. It’s entirely possible the weight and cost kill the economic case but it is likely more possible as a solution than not.
FWIW I’d buy a Lightyear if it were affordable/ available but not because of the solar panels. I’d buy for the efficiency. A car that partly refuels itself on sunny days is an occasional bonus, but the efficiency would be a benefit every day.
OTH if I lived elsewhere let’s say Sri Lanka, I might well take more interest in something like a solar tuk tuk. It’s entirely possible the weight and cost kill the economic case but it is likely more possible as a solution than not.
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
-
?
