Building A Solar Car

 

BUILDING A SOLAR CAR

Solar cars seem like they’re future, complex, super-expensive technology, right? How much of our global warming crisis could be solved if we all drove solar cars? No buying gas! This technology could be closer than you think. Would you imagine that 3 college kids could build a solar car in a garage with only a small amount of money? AND that car could drive from NY to LA on ONLY SUN power?

 

We wanted to show you all how to use sunshine as 100% of the fuel to operate a car. There are only 6 different key components to do that:

 

1) The sun. The sun is made of mostly hydrogen. This hydrogen is undergoing what is called nuclear fusion. This happens when two hydrogen atoms collide and ‘fuse’ a larger atom. It’s a chemical reaction which emits a lot of energy. This fusion reaction is the reason for life on Earth. It warms our planet, feeds our plants, and powers our solar panels.

 

2) The solar array. Similar to how plants use the sun for photosynthesis, our solar panels are able to harness the sun’s energy. However, instead of using the sun’s light to grow, the array converts the energy to create electricity. Our solar panels are only able to harness about 1/5 of the sun’s energy, but that is still enough to power NY2LA. Some solar cars like the University of Michigan Solar Team’s Astrum have custom (expensive) solar arrays which can potentially collect even more of the sun’s energy. NY2LA on the other hand simply uses inexpensive prefabricated solar panels (we’re on a tight budget, right?!). As a result, our panels are much heavier than a custom array, and it makes the car a little less aerodynamic, but the residential solar panels are cheaper and more durable than the custom arrays.

 

3) The charge controller (the brain behind the solar panels). This controller sends electricity to either the motor controller or to the battery. When NY2LA is parked, the motor controller won’t request any electricity from the charge controller. As a result, the controller sends the energy to the batteries to charge. When NY2LA is driving, the charge controller will send electricity to the motor controller. This is ideal, because sending electricity from the charge controller straight to the motor controller is more energy efficient than sending it to the battery and then to the motor controller.

 

Fun fact, if it is a sunny day NY2LA’s solar panels will generate more energy than it needs to drive down the road. This means that NY2LA can drive on the power of the sun exclusively while still charging the battery pack! Just like filling your car with gas at the same time as it’s driving down the road!

 

4) The batteries. NY2LA uses lithium-ion batteries like the batteries used on production Electric Vehicles (EV) you see on the road today. NY2LA uses its battery pack to drive when the sun isn’t shining (at night or on a cloudy day). In fact, when we leave New York City this summer, to avoid traffic, we’ll leave at night and as a result we’ll be running under battery power. The biggest difference between NY2LA’s battery and the batteries seen on EVs today is the size. The best-selling EV in America is the Tesla Model Y which offers battery packs which range from 60-81kWh. The battery pack on NY2LA holds about 5kWh. Part of the reason why NY2LA can have such a small battery pack is because of the solar panels and efficiency.

 

Fun fact, the Tesla Model Y gets about 111MPGe, while NY2LA gets about 650MPGe depending on the conditions!

 

5) Motor controller (the brain behind the motor). The battery and the charge controller both send electricity to the motor controller. The motor controller takes accelerator and brake input from the driver and decides how much electricity is sent to the motor. At times, the motor and motor controller send electricity back to the battery pack. This is called regenerative braking. When the driver presses the brakes, the motor controller on NY2LA essentially puts the motor in reverse. The motor is still spinning forward, but the motor applies a force in the opposite direction. Because of some complicated physics regarding the magnets in the motor, the motor becomes a generator. It operates in the same way as a generator for a house would work. The only difference is that instead of a gas motor spinning the generator, it is the car’s own momentum. This is a key reason why NY2LA and other EVs are so much more efficient than gas- or diesel-powered cars.

A not-so-fun fact, the motor controller on our previous car, Pink Skies, burned up during our 2021 Cannonball Run; forcing us to quit in Indiana.

 

6) The motor. The motor is made up of two main parts, the rotor and the stator. The stator is made up of iron and copper wires. When electricity is sent through these wires it creates a magnetic field. The motor controller can control this magnetic field in a way that moves the rotor. The rotor is the part of the motor that moves, and it is made up of a series of magnets that spin around the stator. The motor on NY2LA is a little different than the motors on traditional EVs. NY2LA’s motor is a ‘hub motor’. This means that the motor is part of the wheel hub. This eliminates the need for a transmission which improves efficiency.

 

Fun fact, depending on driving conditions NY2LA can run on one, two, or three motors. This allows NY2LA to save energy in flat, slow sections of the trip while providing the power to drive through the fast hilly sections!

 

Our journey. We hope that you will follow along this July to see these components in action on our journey from The Red Ball Garage in Manhattan, NYC to The Portofino Bay Hotel in Los Angeles, CA. If 3 friends can build this technology in our garage on a beer (not champagne) budget, as a nation, we absolutely have the ability to make solar cars a big part of our transportation future.

- Kyle, Will and Danny