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There are also flexible CIGS panels which are not fragile and conform well to curved surfaces and are incredibly light weight. I have 960W mounted on my short s

There are also flexible CIGS panels which are not fragile and conform well to curved surfaces and are incredibly light weight. I have 960W mounted on my short school bus conversion and am able to run fridge 24/7, water pump, lights, and an induction cook top and have yet to fully drain the two lithium batteries I got. If any community is aware of the advances made in consumer solar recently it's the skoolie/vanlife folks. I think they improve the car not just from a convenience perspective (i rarely drive more than 100 miles a week in the city) but also it helps more of your energy usage come from the sun rather than non-renewable sources you might be indirectly pulling from the wall.

Rule35 6y ago
Bus roofs are much better for solar than compact cars and you have a use for that incidental power in a way a car does not. As for the car, I imagine people will burn the energy and more by turning on the air conditioning when they get into their hot car that they intentionally parked in the sun. Did you glue(/etc) the panels to the roof or did you have to mount them on standoffs?
- kamranjon 6y ago
  I used VHB tape underneath and Eternabond tape over seams to prevent wind from getting underneath - each 60w panel is 2-3 pounds so very light compared to more common panels that need to be structurally mounted to the frame.
  - Rule35 6y ago
    Sounds pretty nice and fairly foolproof. I remember seeing my first solar panel leaning against an old blue and white school bus at a music festival somewhere on the west coast, decades ago. They had a bunch of old auto batteries for storage.
- rbanffy 6y ago
  > turning on the air conditioning You could cool it a bit with a Stirling engine and get a little more power from the overheated interior. ;-)
  - nomel 6y ago
    And you could use some of the extra heat in hot air balloons to offset the weight of all the Stirling engines.
flavius29663 6y ago
> an induction cook top You make it sound like you're using a lot of power in that bus, but an induction cook top is at most 2-3 KW. That is 4 horse power. If you want to crawl at 5 mph that might be enough (but not for a skoolie anyway). Cars have a huge power-plant under the hood. 100kW per car, at least. All the cars in a city have far more power than the power plant that supplies the city. Think 10k cars (town)= 1 GW. That is a nuclear reactor... All the cars in the US, 275 million vehicles, at an average of 100KW, have a combined power of 27.5 TW. The total installed electrical power plants in the US are around 0.5 TW. The whole world has only 6 TW of installed power plants. Cars need a lot of power...
- kamranjon 6y ago
  Are you assuming that the sunlight needs to directly power the car? The idea, and especially with the car in the article here, is that your car can charge over the course of a few days. The power for electric cars is delivered from the battery. The Chevy Bolt for example has a 60kwh battery. If you have 1kw of solar, it will take you 60 hours of sunlight to charge that battery assuming the efficiency of those cells is close to what they're rated for. The car from the article has a 35kwh battery so around 35 hours of sunlight to fully charge on 1kw of solar. If I drive ~100 miles in the city every week, and the car from the article gets the claimed 200-220w/m2 of solar - It's definitely feasible to recoup your entire driving usage by it just basking in the sun when you aren't using it.
  - flavius29663 6y ago
    I am saying it's not really feasible. To charge a 35kWh battery in 35 hours, you need a constant 1kW. 1kW is a LOT when it comes to mobile PV panels, converted bus campers don't have that much usually. Earth receives 1kW of power from the sun, per square meter. A solar panel has an efficiency of 20%. So under ideal conditions, sun directly at 90%, no shades, you get 200W per sqm. Now, you have shades, less than 90% angles, dirt, etc. On average in the US, the capacity factor of solar PV farms is 25% (includes day/night changes). You will get less on your car, but let's say you do get 25% capacity factor. That leaves you with 1000 * 0.2 * 0.25 = 50W per square meter, 24/7. In a week that is 8400 Wh per square meter. To charge the 35kWh battery once a week, you need 35/8.4 ~ 4 square meters. 4 square meters is plausible. You could say that the car has more space for PVs, but you kind of have to mount them such that they have a decent angle, otherwise their efficiency drops 10 fold. In the case of Chevy Bolt, if you have a 1kW of PV panels, used in ideal conditions, you would need 1kW * 0.25 * 240h = 60kW. 10 days to fully charge the 60kWh battery. If you manage to install 1kW (4-5 square meters) of panels on a volt at ideal conditions (tilted 30-35%), then you could drive it 200 miles every 10 days. On the other hand, if you only drive 20 miles a day, you could recharge at a power outlet and 60kWh would cost you 6 dollars. 6 dollars per 10 days, that means fuel cost would be $219 a year. That is $3200 for 15 years. Is it really worth installing a heavy and complex system on the car if you can achieve the same and better results by just laying the panels on the ground, next to the carport? I am all for integrating solar PV in a lot more things, like house sidings and windows, but putting it on cars is just a PR move.
rootusrootus 6y ago
> flexible CIGS panels which are not fragile However, they do degrade noticeably over the space of even a couple years.

Rule35 6y ago

Bus roofs are much better for solar than compact cars and you have a use for that incidental power in a way a car does not. As for the car, I imagine people will burn the energy and more by turning on the air conditioning when they get into their hot car that they intentionally parked in the sun. Did you glue(/etc) the panels to the roof or did you have to mount them on standoffs?

kamranjon 6y ago
I used VHB tape underneath and Eternabond tape over seams to prevent wind from getting underneath - each 60w panel is 2-3 pounds so very light compared to more common panels that need to be structurally mounted to the frame.
- Rule35 6y ago
  Sounds pretty nice and fairly foolproof. I remember seeing my first solar panel leaning against an old blue and white school bus at a music festival somewhere on the west coast, decades ago. They had a bunch of old auto batteries for storage.
rbanffy 6y ago
> turning on the air conditioning You could cool it a bit with a Stirling engine and get a little more power from the overheated interior. ;-)
- nomel 6y ago
  And you could use some of the extra heat in hot air balloons to offset the weight of all the Stirling engines.

flavius29663 6y ago

> an induction cook top You make it sound like you're using a lot of power in that bus, but an induction cook top is at most 2-3 KW. That is 4 horse power. If you want to crawl at 5 mph that might be enough (but not for a skoolie anyway). Cars have a huge power-plant under the hood. 100kW per car, at least. All the cars in a city have far more power than the power plant that supplies the city. Think 10k cars (town)= 1 GW. That is a nuclear reactor... All the cars in the US, 275 million vehicles, at an average of 100KW, have a combined power of 27.5 TW. The total installed electrical power plants in the US are around 0.5 TW. The whole world has only 6 TW of installed power plants. Cars need a lot of power...

kamranjon 6y ago
Are you assuming that the sunlight needs to directly power the car? The idea, and especially with the car in the article here, is that your car can charge over the course of a few days. The power for electric cars is delivered from the battery. The Chevy Bolt for example has a 60kwh battery. If you have 1kw of solar, it will take you 60 hours of sunlight to charge that battery assuming the efficiency of those cells is close to what they're rated for. The car from the article has a 35kwh battery so around 35 hours of sunlight to fully charge on 1kw of solar. If I drive ~100 miles in the city every week, and the car from the article gets the claimed 200-220w/m2 of solar - It's definitely feasible to recoup your entire driving usage by it just basking in the sun when you aren't using it.
- flavius29663 6y ago
  I am saying it's not really feasible. To charge a 35kWh battery in 35 hours, you need a constant 1kW. 1kW is a LOT when it comes to mobile PV panels, converted bus campers don't have that much usually. Earth receives 1kW of power from the sun, per square meter. A solar panel has an efficiency of 20%. So under ideal conditions, sun directly at 90%, no shades, you get 200W per sqm. Now, you have shades, less than 90% angles, dirt, etc. On average in the US, the capacity factor of solar PV farms is 25% (includes day/night changes). You will get less on your car, but let's say you do get 25% capacity factor. That leaves you with 1000 * 0.2 * 0.25 = 50W per square meter, 24/7. In a week that is 8400 Wh per square meter. To charge the 35kWh battery once a week, you need 35/8.4 ~ 4 square meters. 4 square meters is plausible. You could say that the car has more space for PVs, but you kind of have to mount them such that they have a decent angle, otherwise their efficiency drops 10 fold. In the case of Chevy Bolt, if you have a 1kW of PV panels, used in ideal conditions, you would need 1kW * 0.25 * 240h = 60kW. 10 days to fully charge the 60kWh battery. If you manage to install 1kW (4-5 square meters) of panels on a volt at ideal conditions (tilted 30-35%), then you could drive it 200 miles every 10 days. On the other hand, if you only drive 20 miles a day, you could recharge at a power outlet and 60kWh would cost you 6 dollars. 6 dollars per 10 days, that means fuel cost would be $219 a year. That is $3200 for 15 years. Is it really worth installing a heavy and complex system on the car if you can achieve the same and better results by just laying the panels on the ground, next to the carport? I am all for integrating solar PV in a lot more things, like house sidings and windows, but putting it on cars is just a PR move.

rootusrootus 6y ago

> flexible CIGS panels which are not fragile However, they do degrade noticeably over the space of even a couple years.