4 ms·

Electric car – charged by the sun

37 points by cjbenedikt 10y ago

Pfhreak 10y ago
Ok, I'm willing to believe you could build a car that charges ~15m a day from optimal sunlight exposure. Maybe. But what I don't understand is how having a living moss interior attached to your air supply is anything other than a terrible idea. There are so many edge cases/issues I can imagine with trying to integrate a living component into a car interior. (How does it handle extreme temperatures? How do you manage moisture levels? What happens if it dies? How are you ensuring it remains pest free?)
Shivetya 10y ago
Don't see it. Is there generation amount based on perfect conditions because its quite possible the majority of the car would not have exposure all at once.
sandworm101 10y ago
For the price of integrating the panels into the car you could setup 10x as many panels on a stationary rig. A portable folding rig kept in the trunk is probably a better solution. It could at least be positioned for maximum exposure without trying to angle the entire car. (I predict accidents as people attempt to tilt these things.)
dimman 10y ago
I must say I'm extremely sceptical as it would surprise me _a lot_ if they managed to pull this off with a couple hundred k euros; meaning that they produce something that 1) Actually works, 2) Is rather solid, and perhaps most important of all 3) Is not a disaster in terms of safety.
whazor 10y ago
A previous student team who won the solar race from the Netherlands is also planning to go into the solar car industry.
lumberjack 10y ago
12.000/16.000€ for 120/250km is pretty good if they can manage it. This is now solidly within affordability of everyone. Not sure how they are beating Mitsubishi, Renault and Nissan though. Never mind: 1. The fact that they are raising money through indiegogo heavily implies that they don't have a convincing plan to get their product at the promised price point (which would very definitely sell if they did). 2. They have 9 people on their team. I found the founders the graphic designers and the communications experts but not the engineers. I think this is just another case of "lets make a cool website about a product that is very much in need, raise money, and then start thinking about how to actually deliver".
diafygi 10y ago
EDIT: This screams scam or at least heavily misleading. > A total of 349 SunPower cells are producing 1,144 Watts peak at an efficiency of 22%. EDIT: That's 3.27W/cell, which SunPower cells do provide. I counted the cells: Roof: 114 Hood: 45 Dashboard: 24 Driver Front Door: 33 Driver Rear Door: 21 Driver Rear Panel: 21 Passenger Front Door: 33 Passenger Rear Door: 21 Passenger Rear Panel: 21 ??? unknown location: 16 ------------------------- Total: 349 So only, 52% of the cells will ever have the chance of being positioned correctly. Even still, the angle of the roof cells are curved, so half of those will not be in good positions when the hood is angled directly at the sun. That leaves you with 126 cells that might be positioned correctly, which means a real world capacity of 413 W, which will result in a max range of 23 km (EVs get ~7km/kWh). The 30km range is extremely ideal, and real world is likely closer to 10-20km from 8 hours of solar. That's ~2km per hour of sunlight. Anyway, parking the panels directly in the sun at the ideal angle for 8 hours will be pretty impossible for most people. However, it might have a niche use case for remote research stations or cabins? Unfortunately, the marketing on this makes it seem like this would be good for urban users, so the team appears to be heavily misleading backers (e.g. scam). Cities are extremely bad for solar cars (all the tall buildings make a lot of shade).
onmobiletemp 10y ago
This is a complete waste of time. Cells attached to the car will net you way less energy than they claim (well they claim distance, i dont know if their wh/km or wh from the panels is off, but one or both are). Panels on the car could help prevent charge loss while parked for long periods or in extreme cold but its less and less necessary as capacity steadily increases. The only reason this might be useful is if you want to be a nomad amd never use charging infrastructure. But youd get way more energy for way less money by carrying panels in the trunk of your car or converting a large rv to solar and carrying panels as well. As panels get cheaper we will see more cars with solar but it will be small and for air con and stopping charge loss, not range.
zbrozek 10y ago
Cars competing in the World Solar challenge have a similar number of solar cells. They weigh about 300 kg with occupant and have ridiculously good aerodynamics compared to ordinary cars. Further, their cells are almost all pointed up. Those cars manage about 600 km per day, but are also tilted towards the sun for a couple hours a day in addition to having their cells oriented ~optimally while driving. There's simply no way that anything even vaguely resembling a normal car is going to have that kind of solar energy performance. Having been the team captain of one of those solar race car teams, I long-ago decided that solar panels are best bolted to the ground or a building and the vehicles unburdened of their weight and fragility. I do think cars should have a tiny solar panel built in to them, but it should be there to offset the quiescent load of the body electronics on the low-voltage battery.
- karlding 10y ago
  I believe World Solar Challenge regulations [1] are now only allowing a maximum of 5m^2 for Cruiser class vehicles (mounted to the car itself). +------------+-------------------+---------------------------------+ | Class | PV Cell Chemistry | Allowable Total Cell Area (m^2) | +------------+-------------------+---------------------------------+ | Challenger | Si | 4.000 | +------------+-------------------+---------------------------------+ | Challenger | thin film GaAs | 3.560 | +------------+-------------------+---------------------------------+ | Challenger | multijunction | 2.640 | +------------+-------------------+---------------------------------+ | Cruiser | Si | 5.000 | +------------+-------------------+---------------------------------+ | Cruiser | thin film GaAs | 4.440 | +------------+-------------------+---------------------------------+ | Cruiser | multijunction | 3.300 | +------------+-------------------+---------------------------------+ And then a supplemental array may be carried inside the vehicle only for charging (2m^2 for Si, 1.78m^2 for thin film GaAs, and 1.32m^2 for multijunction). So the total area actually on the cars at WSC would be less. But yeah, as a member of one of these solar car teams, it is hard to design a net-positive vehicle that doesn't resemble a UFO. Cruiser class is a move in that direction, but the most successful teams have an aerobody and chassis optimized to be as flat as possible, to get the most out of their array. [1] https://www.worldsolarchallenge.org/files/1504_2017_bwsc_regulations_final_release_version_11.pdf https://www.worldsolarchallenge.org/files/1504_2017_bwsc_reg...

37 points by cjbenedikt 10y ago

Ok, I'm willing to believe you could build a car that charges ~15m a day from optimal sunlight exposure. Maybe. But what I don't understand is how having a living moss interior attached to your air supply is anything other than a terrible idea. There are so many edge cases/issues I can imagine with trying to integrate a living component into a car interior. (How does it handle extreme temperatures? How do you manage moisture levels? What happens if it dies? How are you ensuring it remains pest free?)

Shivetya 10y ago

Don't see it. Is there generation amount based on perfect conditions because its quite possible the majority of the car would not have exposure all at once.

sandworm101 10y ago

For the price of integrating the panels into the car you could setup 10x as many panels on a stationary rig. A portable folding rig kept in the trunk is probably a better solution. It could at least be positioned for maximum exposure without trying to angle the entire car. (I predict accidents as people attempt to tilt these things.)

dimman 10y ago

I must say I'm extremely sceptical as it would surprise me _a lot_ if they managed to pull this off with a couple hundred k euros; meaning that they produce something that 1) Actually works, 2) Is rather solid, and perhaps most important of all 3) Is not a disaster in terms of safety.

whazor 10y ago

A previous student team who won the solar race from the Netherlands is also planning to go into the solar car industry.

lumberjack 10y ago

12.000/16.000€ for 120/250km is pretty good if they can manage it. This is now solidly within affordability of everyone. Not sure how they are beating Mitsubishi, Renault and Nissan though. Never mind: 1. The fact that they are raising money through indiegogo heavily implies that they don't have a convincing plan to get their product at the promised price point (which would very definitely sell if they did). 2. They have 9 people on their team. I found the founders the graphic designers and the communications experts but not the engineers. I think this is just another case of "lets make a cool website about a product that is very much in need, raise money, and then start thinking about how to actually deliver".

diafygi 10y ago

EDIT: This screams scam or at least heavily misleading. > A total of 349 SunPower cells are producing 1,144 Watts peak at an efficiency of 22%. EDIT: That's 3.27W/cell, which SunPower cells do provide. I counted the cells: Roof: 114 Hood: 45 Dashboard: 24 Driver Front Door: 33 Driver Rear Door: 21 Driver Rear Panel: 21 Passenger Front Door: 33 Passenger Rear Door: 21 Passenger Rear Panel: 21 ??? unknown location: 16 ------------------------- Total: 349 So only, 52% of the cells will ever have the chance of being positioned correctly. Even still, the angle of the roof cells are curved, so half of those will not be in good positions when the hood is angled directly at the sun. That leaves you with 126 cells that might be positioned correctly, which means a real world capacity of 413 W, which will result in a max range of 23 km (EVs get ~7km/kWh). The 30km range is extremely ideal, and real world is likely closer to 10-20km from 8 hours of solar. That's ~2km per hour of sunlight. Anyway, parking the panels directly in the sun at the ideal angle for 8 hours will be pretty impossible for most people. However, it might have a niche use case for remote research stations or cabins? Unfortunately, the marketing on this makes it seem like this would be good for urban users, so the team appears to be heavily misleading backers (e.g. scam). Cities are extremely bad for solar cars (all the tall buildings make a lot of shade).

onmobiletemp 10y ago

This is a complete waste of time. Cells attached to the car will net you way less energy than they claim (well they claim distance, i dont know if their wh/km or wh from the panels is off, but one or both are). Panels on the car could help prevent charge loss while parked for long periods or in extreme cold but its less and less necessary as capacity steadily increases. The only reason this might be useful is if you want to be a nomad amd never use charging infrastructure. But youd get way more energy for way less money by carrying panels in the trunk of your car or converting a large rv to solar and carrying panels as well. As panels get cheaper we will see more cars with solar but it will be small and for air con and stopping charge loss, not range.

zbrozek 10y ago

Cars competing in the World Solar challenge have a similar number of solar cells. They weigh about 300 kg with occupant and have ridiculously good aerodynamics compared to ordinary cars. Further, their cells are almost all pointed up. Those cars manage about 600 km per day, but are also tilted towards the sun for a couple hours a day in addition to having their cells oriented ~optimally while driving. There's simply no way that anything even vaguely resembling a normal car is going to have that kind of solar energy performance. Having been the team captain of one of those solar race car teams, I long-ago decided that solar panels are best bolted to the ground or a building and the vehicles unburdened of their weight and fragility. I do think cars should have a tiny solar panel built in to them, but it should be there to offset the quiescent load of the body electronics on the low-voltage battery.

karlding 10y ago
I believe World Solar Challenge regulations [1] are now only allowing a maximum of 5m^2 for Cruiser class vehicles (mounted to the car itself). +------------+-------------------+---------------------------------+ | Class | PV Cell Chemistry | Allowable Total Cell Area (m^2) | +------------+-------------------+---------------------------------+ | Challenger | Si | 4.000 | +------------+-------------------+---------------------------------+ | Challenger | thin film GaAs | 3.560 | +------------+-------------------+---------------------------------+ | Challenger | multijunction | 2.640 | +------------+-------------------+---------------------------------+ | Cruiser | Si | 5.000 | +------------+-------------------+---------------------------------+ | Cruiser | thin film GaAs | 4.440 | +------------+-------------------+---------------------------------+ | Cruiser | multijunction | 3.300 | +------------+-------------------+---------------------------------+ And then a supplemental array may be carried inside the vehicle only for charging (2m^2 for Si, 1.78m^2 for thin film GaAs, and 1.32m^2 for multijunction). So the total area actually on the cars at WSC would be less. But yeah, as a member of one of these solar car teams, it is hard to design a net-positive vehicle that doesn't resemble a UFO. Cruiser class is a move in that direction, but the most successful teams have an aerobody and chassis optimized to be as flat as possible, to get the most out of their array. [1] https://www.worldsolarchallenge.org/files/1504_2017_bwsc_regulations_final_release_version_11.pdf https://www.worldsolarchallenge.org/files/1504_2017_bwsc_reg...