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Having the solar cells on the side looks like a wrong design. But let's assume there is some on the roof. 1sqm of panel in Sri Lanka shd generate 150 Watts duri

Having the solar cells on the side looks like a wrong design. But let's assume there is some on the roof. 1sqm of panel in Sri Lanka shd generate 150 Watts during clear day, according to one source you need 6.8kwh (which sounds too high for me) for 20km im urban area, 44hours of charging. 2sqm 22 hours.

jacquesm 5y ago
If the panels catch some light while it is moving it might make for a good assist, 150 watts extra is nothing to sneeze at with a pedal powered vehicle. When I'm cycling longer distances I can sustain 80-125 watts for 3 hours or so, which is definitely not athlete material but pretty decent for an old guy with a gimp leg ;) Going uphill that would make a huge difference (especially because a Tuk-Tuk is quite heavy), more so if you can store the power when you don't need it and dump it all in one go when you're going uphill, but then you'd need to have a battery in the system.
- andi999 5y ago
  Is the device in the article pedal powered?
  - jacquesm 5y ago
    Hm, good point, I can't find any drive train components at all when playing the video frame-by-frame. Neither motor nor pedals & chain, unless he's using a hub motor in the front? Edit: just found this: https://electricalconnection.com.au/the-future-of-electric-vehicles-crossing-australia-in-a-solar-tuk-tuk/ https://electricalconnection.com.au/the-future-of-electric-v... Which makes me wonder how viable this particular reincarnation of the concept is. They have far more panels, have them facing up (which is good), have a much more efficient battery and still need a socket to charge up the battery because there isn't enough power from the panels. Edit2: I noticed all of the panels except for the 'door' have hinges at the top, I suspect they are placed horizontal for charging purposes. If not augmented by another power source then I suspect it has a very low duty cycle.
    - andi999 5y ago
      It generates viable publicity.
2Gkashmiri 5y ago
i own an electric scooter which is a 250 Watt motor and has a 48V 24Ah battery so 1KWH. this gives me about 50 Km for one charge. on this scooter, i put over 220 KG of load and it runs so there should be no problems putting two of those motors in a three wheel design. about power, i am sure this is just for "topping up" the battery because one can have a battery bank at home which charges from sun which can be swapped for next day. that way you can put even a 330 watt panel and that should charge this system during the entire day. then you have to account for cloudy days and such so maybe bump the solar up so if you put something like 500 Watts or more with a second battery pack of 2+ Kwh, that should be comfortable
kwhitefoot 5y ago
In good dry Norwegian summer weather, at a steady 90 kph on the flat, my 2015 Model S 70D will consume about 170 Wh/km, that's 3.4 kWh for 20 km. So 6.8 kWh for urban driving with what is probably a much less efficient drive train sounds a bit high but not wildly off.
- Someone 5y ago
  Google tells me your car weighs 2090kg/4647 pounds. This tuk tuk probably weighs a tenth of that. Add passengers, and you probably are still looking at a factor of 5. Also, I don’t think 90kph is a realistic cruising speed for this tuk tuk. Assuming 22kph, that’s a factor of 16 in air resistance. The Tesla wins on a aerodynamics, though, and rolling resistance could be lower for a Tesla/US road than this tuk tuk/Sri Lankan road. Overall, I would guess you would need a factor of 10 or so to compare the two vehicles (but that’s a wild guess/gut feeling. If humans had 8 or 12 fingers, chances were my guess would be 8 respectively 12).
  - kwhitefoot 5y ago
    You are right of course about the tuk-tuk not cruising at 90 kph. I used that because consumption at that speed is about the only figure I can be confident of regarding the Tesla; it's hard to find a road where I can travel the requisite 10 km at 22 kph to get a good consumption reading. Perhaps I'll give it a try if I can find a place to do it, I read somewhere that someone did an economy run in a Model S and got a thousand km range at something like 30 kph. I think that the Tesla probably benefits from an economy of scale both in manufacturing volume and advanced motor and inverter design. According to our favourite search engine tuk-tuks weigh between 250 and 450 kg so with driver and passenger the smaller ones are about one sixth the mass of my car, the bigger ones a bit over a quarter. The small motor in the tuk-tuk is probably much less efficient than the Tesla motor even in the middle of its power range. Also I doubt that the tuk-tuk would have especially effective regenerative breaking because doing this automatically requires coordination with the mechanical brakes. I'm pretty confident that no vehicle in the tuk-tuk weight class other than some specially designed research vehicle will travel a kilometre on only 17 Whr, certainly not one carrying passengers. The losses will be dominated by rolling resistance. Or did I misinterpret your factor of ten? For comparison an electric scooter with a 36 V, 7.5 Ah battery has a range of 25 km, that's 10.8 Wh/km. See https://stayclassy.no/collections/el-sparkesykkel/products/classywalk-s50-n-elektrisk-sparkesykkel https://stayclassy.no/collections/el-sparkesykkel/products/c... Anyway, none of this is meant to detract from the achievement of the guy with the solar powered tuk-tuk. P.s. not that it makes any real difference but the roads are Norwegian not US. :-)
real-dino 5y ago
out of direct sunlight, solar panels can produce a 3rd of their max output from ambient. This is only during the day. Ambient light however, cannot travel even a km, as soon as the sun stops hitting that part of the earth, the output drops to zero. This is despite the human eye being able to see.
- andi999 5y ago
  Why not put them on the homes roof and get 3 times more harvest.
  - jacquesm 5y ago
    Because the math doesn't work out, see my other comment.
- jacquesm 5y ago
  That's a misinterpretation of the data. The incident radiation is on the order of 100 W / square meter (10K Lux max, and probably much less depending on local conditions) from ambient (versus about 1KW / square meter for direct sunlight, 120K Lux), the panels then extract about 10% of that, so 10 W give or take for a panel area that would produce 250 to 300W when exposed to full sunlight. Ambient light tends to be reflected more than direct sunlight due to the percentage of the photons arriving at an angle < 45 degrees relative to the plane, which means they'll very likely bounce off. This is why it isn't cost effective to put solar panels facing North on a roof, and panels facing East or West will only be producing power for a small part of the day.
taneq 5y ago
If you've got a pile of solar cells sitting around you might as well use them to make the doors too. I agree, though, that even if it only draws 500W then this thing is only going to be driving for a few minutes a day on that amount of panels. Cool scooter for a highschool kid though!

jacquesm 5y ago

If the panels catch some light while it is moving it might make for a good assist, 150 watts extra is nothing to sneeze at with a pedal powered vehicle. When I'm cycling longer distances I can sustain 80-125 watts for 3 hours or so, which is definitely not athlete material but pretty decent for an old guy with a gimp leg ;) Going uphill that would make a huge difference (especially because a Tuk-Tuk is quite heavy), more so if you can store the power when you don't need it and dump it all in one go when you're going uphill, but then you'd need to have a battery in the system.

andi999 5y ago
Is the device in the article pedal powered?
- jacquesm 5y ago
  Hm, good point, I can't find any drive train components at all when playing the video frame-by-frame. Neither motor nor pedals & chain, unless he's using a hub motor in the front? Edit: just found this: https://electricalconnection.com.au/the-future-of-electric-vehicles-crossing-australia-in-a-solar-tuk-tuk/ https://electricalconnection.com.au/the-future-of-electric-v... Which makes me wonder how viable this particular reincarnation of the concept is. They have far more panels, have them facing up (which is good), have a much more efficient battery and still need a socket to charge up the battery because there isn't enough power from the panels. Edit2: I noticed all of the panels except for the 'door' have hinges at the top, I suspect they are placed horizontal for charging purposes. If not augmented by another power source then I suspect it has a very low duty cycle.
  - andi999 5y ago
    It generates viable publicity.

2Gkashmiri 5y ago

i own an electric scooter which is a 250 Watt motor and has a 48V 24Ah battery so 1KWH. this gives me about 50 Km for one charge. on this scooter, i put over 220 KG of load and it runs so there should be no problems putting two of those motors in a three wheel design. about power, i am sure this is just for "topping up" the battery because one can have a battery bank at home which charges from sun which can be swapped for next day. that way you can put even a 330 watt panel and that should charge this system during the entire day. then you have to account for cloudy days and such so maybe bump the solar up so if you put something like 500 Watts or more with a second battery pack of 2+ Kwh, that should be comfortable

kwhitefoot 5y ago

In good dry Norwegian summer weather, at a steady 90 kph on the flat, my 2015 Model S 70D will consume about 170 Wh/km, that's 3.4 kWh for 20 km. So 6.8 kWh for urban driving with what is probably a much less efficient drive train sounds a bit high but not wildly off.

Someone 5y ago
Google tells me your car weighs 2090kg/4647 pounds. This tuk tuk probably weighs a tenth of that. Add passengers, and you probably are still looking at a factor of 5. Also, I don’t think 90kph is a realistic cruising speed for this tuk tuk. Assuming 22kph, that’s a factor of 16 in air resistance. The Tesla wins on a aerodynamics, though, and rolling resistance could be lower for a Tesla/US road than this tuk tuk/Sri Lankan road. Overall, I would guess you would need a factor of 10 or so to compare the two vehicles (but that’s a wild guess/gut feeling. If humans had 8 or 12 fingers, chances were my guess would be 8 respectively 12).
- kwhitefoot 5y ago
  You are right of course about the tuk-tuk not cruising at 90 kph. I used that because consumption at that speed is about the only figure I can be confident of regarding the Tesla; it's hard to find a road where I can travel the requisite 10 km at 22 kph to get a good consumption reading. Perhaps I'll give it a try if I can find a place to do it, I read somewhere that someone did an economy run in a Model S and got a thousand km range at something like 30 kph. I think that the Tesla probably benefits from an economy of scale both in manufacturing volume and advanced motor and inverter design. According to our favourite search engine tuk-tuks weigh between 250 and 450 kg so with driver and passenger the smaller ones are about one sixth the mass of my car, the bigger ones a bit over a quarter. The small motor in the tuk-tuk is probably much less efficient than the Tesla motor even in the middle of its power range. Also I doubt that the tuk-tuk would have especially effective regenerative breaking because doing this automatically requires coordination with the mechanical brakes. I'm pretty confident that no vehicle in the tuk-tuk weight class other than some specially designed research vehicle will travel a kilometre on only 17 Whr, certainly not one carrying passengers. The losses will be dominated by rolling resistance. Or did I misinterpret your factor of ten? For comparison an electric scooter with a 36 V, 7.5 Ah battery has a range of 25 km, that's 10.8 Wh/km. See https://stayclassy.no/collections/el-sparkesykkel/products/classywalk-s50-n-elektrisk-sparkesykkel https://stayclassy.no/collections/el-sparkesykkel/products/c... Anyway, none of this is meant to detract from the achievement of the guy with the solar powered tuk-tuk. P.s. not that it makes any real difference but the roads are Norwegian not US. :-)

real-dino 5y ago

out of direct sunlight, solar panels can produce a 3rd of their max output from ambient. This is only during the day. Ambient light however, cannot travel even a km, as soon as the sun stops hitting that part of the earth, the output drops to zero. This is despite the human eye being able to see.

andi999 5y ago
Why not put them on the homes roof and get 3 times more harvest.
- jacquesm 5y ago
  Because the math doesn't work out, see my other comment.
jacquesm 5y ago
That's a misinterpretation of the data. The incident radiation is on the order of 100 W / square meter (10K Lux max, and probably much less depending on local conditions) from ambient (versus about 1KW / square meter for direct sunlight, 120K Lux), the panels then extract about 10% of that, so 10 W give or take for a panel area that would produce 250 to 300W when exposed to full sunlight. Ambient light tends to be reflected more than direct sunlight due to the percentage of the photons arriving at an angle < 45 degrees relative to the plane, which means they'll very likely bounce off. This is why it isn't cost effective to put solar panels facing North on a roof, and panels facing East or West will only be producing power for a small part of the day.

taneq 5y ago

If you've got a pile of solar cells sitting around you might as well use them to make the doors too. I agree, though, that even if it only draws 500W then this thing is only going to be driving for a few minutes a day on that amount of panels. Cool scooter for a highschool kid though!