Open Solar Car

Hey! Does anyone has any information on what would be the best way to construct an solar powered car? I know, this is a big project, but I would really like to do it in the future (if I have the resources). I was thinking about something like OSVehicle: https://www.osvehicle.com With open source schematics (freecad), and solar panels on the car. A redundancy system (more batteries) and a KERS (kinetic energy recovery system) on the breaks. Airless tires for low maintenance. It should also have a good aerodynamic shape ("water drop" shape?) and a very lightweight structure. Maybe a system to control energy flux, using SabreLite board and seL4... Or maybe not a car, because it's too heavy? A tricycle? Any ideas?

>>358 Go do what the edison2 did and not reinvent the wheel. Ultralight car borrowing from kitplane design with a small methanol fueled engine will do much better than most whatever you can come up with. Don't start with symphonies before you learn how to play chopsticks, the issue with electric cars is energy storage which isn't something you can deal with on your own. If you are set on this, make some close friends with your local university's engineering department because you're going to be on the cutting edge.

Maximum payload (people + passengers)? Maximum level-ground speed? Can the car run continuously in full sunlight without depleting the solar panels, or must it stop to charge?

>>360 I'm not reinventing the wheel. I just want to make a solar car. Also, methanol is not renewable and I would waste money build tanks for it. Solar energy comer 'for free'. But thanks for the tip on the edison2, didn't know that. >>361 >max payload 2 people (~100kg/person) >maximum speed 80km/h is enough >charge Continuous charge from embedded solar panels and KERS system.

>>362 Methanol can be renewable, it can even be harvested from industrial/residential waste and in fact is in many places. A local land fill does this. I'd say it's far more realistic to plan for synthesized methanol than to expect the sort of energy you'll need to operate your vehicle to be harvested from an on board solar array. Especially the load and velocity you expect. However I don't mean to belittle you or discourage you from your idea. It would be really cool. Maybe a hybrid type system? Since it's already an electric vehicle, why not have a power bank that can be supplemented by solar power and charged elsewhere? I just don't think solar is going to give you the sort of power output you're expecting from the area you'll have to work with on a vehicle. this article explains why continuous use solar cars probably won't be a reality: http://www.washingtontimes.com/blog/spinning-wheels-community-car-lovers/2008/jul/26/why-there-wont-be-a-solar-powered-car/ However, as some in the comments have pointed out a solar power system could be used to passively charge the vehicle. I would question, though, why not just have a stationary solar array that could be mounted on a orientation system to better capture energy throughout the day which could be stored to charge the car when you need it? Why does it need to be on the car?

These Michelin airless tires seems really cool: https://www.youtube.com/watch?v=4IDmpXbK-Mk

>>363 Thanks for all this information dude, I appreciate it. >However I don't mean to belittle you or discourage you from your idea I know you don't. I like criticism, that's why I'm here and not on other place. >methanol I'll look further into it. >why not have a power bank that can be supplemented by solar power and charged elsewhere? Yeah, that was my idea on the first place. Externalize the solar panel could be a good idea, indeed, since it would reduce the weight. >Why does it need to be on the car? It don't, but would be cool to have it running on it's own, without need to other type of energy. But I'll read the article you linked.

I like the Edison2 design.

The desired speed is 80 km/hr. This is 22.2 m/sec. The force required to overcome drag is [1]: 0.5 * air density * drag coefficient * reference area * speed² 0.5 * 1.184 kg/m³ (25°C, sea level) [2] * 0.3 (typical modern car) [3] * 1 m² (velomobile or very small car) * (22.2 m/sec)² = 0.5 * 1.184 * 0.3 * 1 * 22.2² = 0.5 * 1.184 * 0.3 * 1 * 493.7 = 87.7 newtons 1 joule is 1 newton exerted over a distance of 1 meter. 87.7 joules (required to move each meter) * 22.2 meters (per second, 80 km/hr) = 1950 Watts (joule-seconds) "electric drive vehicles have on-board efficiency of around 80%" [4] 1950 Watts / 0.8 = 2440 Watts "costs of US$0.37/Wp (Watt, Peak) in the third quarter of 2016" [5] 2440 Watts * 0.37 USD/Watt = 902.8 USD According to [6], modern consumer-end (mono- or polycrystalline silicon) have an efficiency of ~23%. "when the Sun is at the zenith... the total amount (of sunlight) hitting the ground is around 1120 W/m²" [7] 2440 Watts / 0.23 / 1120 W/m² = 9.47 m² of solar cells [1] https://en.wikipedia.org/wiki/Drag_coefficient [2] https://en.wikipedia.org/wiki/Density_of_air [3] https://en.wikipedia.org/wiki/Automobile_drag_coefficient#Typical_drag_coefficients [4] https://en.wikipedia.org/wiki/Electric_car#Energy_efficiency [5] https://en.wikipedia.org/wiki/Solar_cell#Declining_costs_and_exponential_growth [6] https://upload.wikimedia.org/wikipedia/commons/3/3d/PVeff%28rev170414%29.jpg [7] https://en.wikipedia.org/wiki/Sunlight#Measurement

>>369 wow, thanks for this.

This is better

>>387 I think that it would be much more practical to start by just building an electric vehicle. Once you have something that can move around without catching fire. Then, as a substantial modification, add enough solar cells to charge it in a reasonable amount of time while not driving. That alone will be challenging enough -- getting the electronics right so that things run efficiently without degrading the batteries or bursting into flames if you start driving with the PV cells still connected, protecting the solar cells from harm while driving (or while parked), and not adding too much weight or drag to the vehicle.

>>358 There are multiple significant factors that you will need to take into consideration: >The level of power generation from the power source (solar cells). >The energy consumption of the propel system and general vehicle (Electrical engines, lighting, computer systems, etc.) >Storage capacity of batteries You are going to want to make this car as small, light, aerodynamic, efficient, etc. as possible. You will want to avoid the amount of vertical areas when viewing the front of the car, think of the front of a rear engine school bus. so it should be as pointed as possible with the least amount of vertical inclines, similar to a bar of soap (/o/ likes to compare modern sedans to bars of soap due to their design...). This may not be what you desire, but you could install a small internal combustion engine (typical gasoline engine) within the car connected to multiple alternators to charge and power the car in use, this would require gasoline and would generate significant heat, but you could eliminate the need of a larger battery with this... I seriously hope you are a skilled engineer, most individuals cannot understand just how much engineering and calculations go into creating mainstream cars, there are massive teams of engineers behind these companies. I would advise starting from the chassis and engine system of the car, and build from there. Try to draw pictures of what you want, determine the dimensions of the car, and start...

>>389 what the fuarrrk is that?

My idea has been to convert my MK4 Jetta to electric and to mount a small generator in the vehicle. I personally don't think it would defeat the purpose since the electrical wattage production is much more efficient gas-wise than say the momentum needed to drive a car. So in essence you would just need to generate enough power to similtaniously charge the batteries and drive your motors. If that is just too much power for some reason, I have not done any actual calculations, then I would just stop to charge the batteries when needed. You would still be using gas, but I believe you would go significantly further than a gas motor would for less. Also you can run it on hydrogen gas while producing it ondemand. You would just want a water purification system on hand if you planned on traveling farther than your travel radius. You should also be able to mount alternators to moving parts of the car to generate power. The solar cells are a good idea, but idk how many you would need to consistently power your vehicle. They could be used in parallel to your other electrical generation devices in order to offshoot resource consumption.

>>561 looks like Batou's car from GiTS, namely a concept for recent motion picture

With a car consisting of solar cells covering every exposed surface and a fuel-cell/battery for energy storage, you're basically going to be sitting inside a potentially lethal electrical appliance. You'll need to put a lot of thought into how to not get electrocuted, especially in an accident.

I was actually just looking into wheel-hub motors. Looks like it would be expensive, but worth it. You would have a high performance electric vehicle for part of the cost of a new EV. You can do 2 or 4 wheel drive. Could put it in a truck or potentially in a camper.