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this post was submitted on 16 Oct 2023
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I can’t YET, this is clearly early technology, in a few years who knows. Remember we went from not being able to fly to landing on the moon in a lifetime
The problem is, there just isn't that much energy in sunlight, so even a perfect solar panel that captured 100% of the sun's energy wouldn't get you very far.
nope. not "yet". just not physically possible. even with 100% efficient panels.
There just is not enough energy in the sunlight hitting the car. You would have to somehow make the sun shine brighter. Which is not really possible.
The amount of power is limited, but can't the tech improve to make cars that require less power?
you can make the engine more efficient, but at some point there is a minimum amount of energy needed to get the thing moving and they are already quite close to fully efficient. To reduce energy needed any further you can make the car lighter, but that obviously cannot be improved indefinitely.
Wait wait, how are you calculating that? If you take a generic sea level solar irradiance of 6kWh/day/m^2^ and let's assume the car has a solar panel area of 3m^2^ (probably more, but maybe not all exposed at the same time) with a solar panel efficiency up to 30% and the cosine for solar angle (say ~0.7), given the best 0.137 kWh/km around, that gives around 30km a day. That's already enough for my weekday return commute.
All this neglects shade, cloudy days, won't work for all latitudes...but it can also be upgraded with improved battery storage/weight, improved solar panel efficiency and maybe even the area of the car top and shape of panels can be improved (e.g. make them extendable/orientable when parked). At worst, you just top it up to 500km from the grid every weekend and that will make up for the difference over the course of the week.
I have a golf cart I use for most of my short drives. I’ve been thinking about putting solar on the roof and figuring out how to do all these calculations so I can decide if it would be worth it based on my use case. I like to keep it in my garage out of the weather when I’m not using it unfortunately. Feel like it will last me forever if I take care of it like that instead of leaving it outside and in not sure if Solar would be worth it for while I’m driving or out at the store or visiting someone.
Fuck, don't give them ideas, climate change is bad enough as it is...
I'm not very well versed in solar tech, but what I think I know is that we've already approached about the max efficiency out of solar already, so there probably won't be large gains going forward.
silicon solar panels are at their limit which is something like 30% efficient. Newer chemistry will go beyond that but as the other comment said even with double the power there isn't enough energy in sunlight for a car sized panel to get a car going for too long. Especially when there are clouds out (most of the time here)