For years, genuine solar charged driving or in-situ solar charged driving, took place relatively unnoticed on back roads and special racetracks far removed from the main highways and byways of America. Sleek, aerodynamic (mostly teardrop shaped) cars covered in solar panels silently zipped along in competitions with vehicles mostly piloted by university students and weekend hobbyist.
The vehicles, sometimes just barely large enough to fit one average sized person inside and a little sturdier than light framed bicycles, placed maximum emphasis on speed and distance traveled with a lesser degree of emphasis placed on passenger comfort. After all, the objective was to just arrive at the finish line in the quickest time possible.
This all changed in a big way in 2013, when the Australian World Solar Challenge race (held every 2 years) created a new category in its competition for passenger cars called Cruiser Class. The objective of the latter category competition was that the car not only be able to arrive at the finish line in record time, but it also needed to be able to carry a number of passengers as well as provided a certain degree of comfort for those onboard.
STELLA, the solar vehicle designed by students at the Technical University Eindhoven in the Netherlands won the World Solar Challenge – Cruiser Class in 2013. The group, promotes STELLA as the World’s First Solar Powered Family Car which can hold up to 4 adults, and have since endeavored towards making their car and the concept of in-situ solar charged driving known and accepted by the general public.
In the summer of 2014, The group at TU Eindhoven obtain United States Road Safety Certification for the STELLA vehicle – a first for this type of vehicle.
Obtaining the certification, put STELLA through all the rigorous requirements imposed on other cars that it would be sharing the road with in the USA (safety specs for tires, brakes, steering, suspension, headlights and brake lights among others). The TU Eindhoven team then took the vehicle on a tour of California driving alongside other vehicles from LA to San Francisco on California’s scenic Highway 1.
Continuing to add on to their demarche to create awareness, In February of 2015, the STELLA Team won the Tech Crunchies competition in the “Best Technology Achievement “ category.
The Crunchies is an award ceremony, run by the technology focused web site TechCrunch, which “celebrates the most compelling startups, internet and technology innovations of the year”.
The fact that STELLA won this award competing against heavyweight tech concepts such as ApplePay (from Apple Computer) further validates that this concept is now something that is gathering traction and is beginning to be taken seriously in the different engineering and business circles.
What is very appealing about the STELLA vehicle is that no matter where the vehicle may be, if there is light, the panels mounted on the roof are trickle charging the batteries. This means that the vehicle is being charged while sitting in the parking lot at work or in the driveway at home (no need to remember to “plug it in”).
It is charging while one is out of town on business or the vehicle is parked or used less on the weekend. It is even charging while driving in heavy stop-and- go traffic as well as when at rest at a traffic light. Compare this to the current EV charging scenario where the vehicle must be at a dedicated recharging location (and plugged in) to charge the batteries.
Further adding to the attractiveness is that through slow continuous trickle charging of the onboard batteries, and with the daily consumption of energy during daily commute being less than what is produced by the solar cells – STELLA could, in principle, becomes a net energy generator much like the rooftop of one’s home – provided the vehicle’s onboard batteries have sufficient buffer capacity to store this extra energy.
If the price of solar panels continues to fall, and if the efficiency of solar cells continues to increase while both the price and efficiency of battery storage improves, then this concept will no doubt gain more and more traction and prevalence.
If the daily consumption of stored energy by the driver is less than the energy produced while the vehicle is exposed to light during the day, excess stored energy could then be returned to the home and stored in the home battery bank – provided battery storage is cheaply available at home. The availability of the latter, seems to be the direction in which things are trending.
While the individual amounts of energy fed back may seem small, it’s the multiplication factor that makes this concept enticing.
STELLA is now preparing to compete in the World Solar Race which will take place in Australia in October 2015 and the team at Eindhoven continues to work relentlessly on further improving their in-situ solar charged vehicle design.
The dawn of true in-situ solar charged driving is moving closer and closer to becoming a reality.
Special thanks to Lex Hoefsloot (in the picture at top) , and the rest of the team at Tech University Eindhoven for showing me around the workshop where STELLA lives while not out on the road and for providing all the information for this article.
Some technical specs on STELLA –>
Weight: 855 lbs (388 kg)
Length: 14.7 feet
Width: 5.4 feet
Height: 3.7 feet
Maximum number of passengers: 4 adults
Battery: 139 lbs (63 kg) Li-ion
Top speed: 72 mph (120 km/h)
Energy use: 56.32 Watt-hours per mile ( 0.05632 KW-hr to drive STELLA 1 mile)
Solar panels covering STELLA: 1.6 KW currently costing about $4,000
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