This little solar powered car operates from the power of the sun, but can it be scaled to what we need for practical purposes? And, is the cost feasible? After all, we know that if a mosquito was enlarged to the size of an elephant, it would crush its legs (and make a pretty big bump on your arm).
The answers to the above in terms of electric vehicles are emphatic yes and yes.
Let’s discuss the first question regarding the practicality of solar powered, electric vehicle transportation. For our “historic” NYC to Detroit trip, we will require charging about every 60 miles to try and avoid getting too close to running out of charge. What happens if we run out of charge? Back in 1901, frequent breakdowns and lack of gas stations resulted in many, many automobiles being towed by an enlisted farmer and his horses. We’ll probably call AAA.
On our “EVing” trip, 60 miles is a nice distance because we’re interested in the journey, and there is a lot to see from NY to Detroit and beyond. Maybe EVing will catch on? Just imagine cruising through the heart of our small towns and large cities, and enjoying the countryside in between rather than rushing along an interstate with everything a blur from the start and finish.
The reality is that electric vehicles will increase in range, as already demonstrated by the Tesla Roadster, a beautiful car with excellent performance and a 250 mile charge range. But, charging takes so long, how can that ever be practical? Check out this research paper by Paul Braun’s research group at the University of Illinois. Yes, the paper is a bit of a snooze for most of us, but basically this is saying that they have developed battery electrodes that can charge batteries 10 to 100 times faster than current technologies. And this is just the beginning. Our great research universities are providing the tools and solutions we need for sustainable living. Entrepreneurs will rapidly move these technologies into the marketplace as we’ve seen with so many other technologies.
The rapid advances being made in energy storage systems and increased rate of energy storage charging/discharging technologies means one thing: you are going to be crying for a bathroom break because your car will never, ever need to stop for a charge. You will simply drive over roadway sections that transport an energy charge into your vehicle (while charging your account for it) with the power of a lightning bolt.
Vehicle cost is an even simpler issue than the practical feasibility issue, because just as we’ve seen in flat screen TVs and cell phones, the cost for an EV is going to drop and auto manufacturers’ profit margins are going to increase as they have a much simpler, less expensive car to build than an IC (internal combustion) engine car. The motor of an electric car has one moving part, the “rotor”, compared to hundreds of parts in an IC engine. No exhaust system to corrode or replace, no air filter, no fuel filter, no oxygen sensors, no EGB sensors, no MAP sensor, no oil filter, no oil drips on your garage floor, minimal if any brake pad changes. Full torque at zero RPMs! And no noise nor pollution. Your sound system will sound better than it has in any car you’ve ever owned, whether you’re listening to Sonny Boy Rollins, Johnny Cash or the Pacifica Quartet.
As far as energy cost for driving, the math is very simple. Solar electricity cost 12.5 cents per kWh (kilowatt-hr is the energy unit most utility companies use on your electric bill). These are not some projected costs taken from some pencil-neck study. I know the cost for solar electricity because I design and install solar energy systems. You can read the details on the cost to install a solar PV (photovoltaic) electric system in this article that my son Ben and I wrote for an engineering journal. Electric vehicles, whether from the Ford Focus EV to the Tesla Roadster, obtain about 4 miles for each kWh of energy. This results in a solar powered cost of 3 to 4 cents per mile.
The cost for solar energy is going to keep decreasing as continued increases in solar system performance, increases in manufacturing efficiency, and decreases in installation cost keep driving the cost of solar energy lower. And as the technology matures and this first generation of solar panels are recycled, the cost for solar energy will take a tremendous plunge as most of the hard work of material purification has already been performed. Just as aluminum soda cans re-manufactured from soda can aluminum require a small fraction of cost compared to soda cans made from bauxite ore, the same is true for solar panels. The cover material, frame material, wiring, inverter electrics and photonics material are all recyclable.
The average gasoline powered vehicle is about 30 miles per gallon of gasoline with a current cost of $3 to $4 per gallon (want to bet on it staying at that cost?). Dividing the cost per gallon by the mileage per gallon, we find that on average the cost per mile is somewhat greater than 10 cents per mile, well above that of a solar powered car. Even high mpg cars in the 50 to 60 mpg cost 5 to 6 cents per mile and are not competitive. And, which direction do you think the price of fossil fuels will go in the future?
The area required for solar energy collectors, whether they are on your roof or someone else’s, for providing all of your annual transportation is surprisingly small. In Illinois, about 150 square ft, or smaller than the roof of a carport, is required to produce about 10,000 to 12,000 miles of driving per year. In the cloudy northwest, about 20% more area is needed and in the sunny southwest, about 20% less solar collector area is required.
This is a cool picture that Alex Long, an engineer with Newell Instruments and Equinox Built Environment Engineering, drew for some information on solar powered transportation on our company websites. I like it a lot and thought it would look nice here.