Driving On Sunshine: the Dream of a Solar-Powered Car
For anyone who has ever gone into sticker shock while buying gas, it has been a favorite fantasy: a car that runs on a free (or nearly free) source of energy. Tales abound of inventions that have been repressed by the oil companies or the government. If allowed to reach the market, they would turn our automobiles into fuel-sipping wonders that could go thousands of miles for a few pennies. As a teenager, I heard of a device developed by a guy in Texas. It consisted of multiple carburetors stacked on top of each other. Allegedly, it turned a V-8 pickup into a 100 MPG miracle. Unfortunately, the creator was paid off by big petroleum and his invention was suppressed. I think this was around the same time I heard about the Corvette that was on sale for $200.00. There was only one catch: someone had died in it and the death smell had leeched into the metal itself, making it impossible to remove. If only urban legends were true… Solar-Powered Car: the Real Free-Fuel Vehicle It’s amazing how many of the high-tech devices we use in the 21st century have their roots in research done in the 1950s. For example, the potential of using the sun’s rays to power everyday devices was demonstrated by William G. Cobb on August 31st, 1955. During that year’s month-long Powerama auto show held in Chicago, he unveiled the world’s first solar-powered vehicle. Equipped with 12 photovoltaic (PV) cells, it got from point A to point B just fine, while being driven by nothing but sunshine. There was a slight drawback though that limited its commercial potential. It was only 15 inches long.
The 1987 GM Sunraycer
Despite this limitation, Cobb’s vehicle was a conceptual success. It showed that solar power had a role to play in meeting our transportation needs. Just how large that role will ultimately be is anyone’s guess at this point.
Public interest in alternative energy sources took off in the early 1970s, thanks to that decade’s oil crisis. By the 1980s, the idea of solar-powered vehicles was a hot topic among conservationists, leading to plans for a 1,950 mile race to demonstrate their viability. GM decided to enter the competition, which was set to be held in Australia. Top brass set a goal of building a suitable car within 10 months. To accomplish this, the automaker enlisted the help of Hughes Aircraft and a design firm named AeroVironment.
Dubbed the Sunraycer, the finished vehicle measured 20-feet long from front to end and resembled an elongated flying saucer. Final weight came in at under 600 pounds, including the eight-pound DC motor. One of the innovations included a system that fed power back into the silver-oxide batteries when the brakes were engaged. Now known as regenerative braking, it’s a staple feature of today’s battery-powered cars. The Sunraycer was amazingly fast for a car of its type, with a top speed of 68 MPH (109 km/h). Hughes engineers installed over 8,000 solar cells onto its exterior.
The effort and expense poured into building it paid off when GM not only won the competition but outshone the other entrants, achieving an average speed of 41.5 MPH (66.9 km/h) and finishing the course in just over five days. This was 50% faster than the second place vehicle, and gave the American automaker bragging rights and a reputation as a leader in developing new technology.
Solar-Powered Vehicles Today: Fantasy and Reality
While the dream of powering our transportation from sunlight alone is still alive and well, a number of nagging technical challenges limits its potential. Among these are the effects of clouds and seasonal changes, the relatively low efficiency of current solar panels, and the state of battery technology.
Any commercially viable sun-powered vehicle will have to incorporate batteries to achieve an acceptable rate of speed. This adds hundreds of pounds of weight and thousands of dollars to the cost. Also, constantly discharging and recharging cells necessitates replacing them on a regular basis.
Barring a technological revolution (always a possibility), solar power will likely play at best a supportive role in freeing us from the gas pumps. Still, with research going on constantly, the possibility remains that one day we or our children might drive from coast to coast on nothing but a few rays of sunshine. Time will tell.
The 1987 GM Sunraycer