University of Texas Solar Vehicles Team

The University of Texas Solar Vehicles Team (UTSVT) is a student-driven effort to design, build, test, and race solar vehicles for the purpose of reinforcing skills learned in the classroom, raising awareness of solar power, and bringing solar power closer to practicality. To accomplish this task, a multidisciplinary group of students from various disciplines in the Cockrell School of Engineering, and from other schools across the University of Texas, such as the College of Liberal Arts and the College of Natural Sciences come together to design and construct the most efficient vehicle as possible.

The vehicles are completely powered by the sun and are entered in competitions against universities from across the United States and internationally. The team serves as the host for American Solar Challenge (ASC) and Formula Sun Grand Prix (FSGP). In addition to participating in races, the team participates in outreach events to educate the general public and K-12 students about the excitement of STEM careers and alternative energy.

Texas Native Sun I
UT's first solar car was Texas Native Sun, built with a graphite and epoxy composite monocoque body, 1,000 solar cells, and 66 nickel-hydrogen batteries. A 2 hp high-density permanent magnet electric motor powered its continuously variable transmission. The teardrop-shaped car's length, width, and height were 19 x 6.5 x 5 ft, and it weighed 320 lb. Its top speed was 65 mph. Project advisors included professors Gary Vliet and Ron Matthews.

It competed in three races—Sunrayce 1990 (placed 22nd out of 32), Sunrayce 1993, and the California Clean Air Race 1991 where it placed second out of 30 teams.

Texas Native Sun II
UT's second solar car, Texas Native Sun II, was a two-seater and larger than the first, weighing 1000 lb. It featured a bespoke electric hub motor and controller supplied by lead-acid batteries. Texas Native Sun II raced in the Tour de Sol in 1996 placing fourth in its class.

Solstice
The team's third solar car was named Solstice, which was built for Sunrayce 1999 but never completed.

Solar Steer
With construction beginning in 2004, Solar Steer was UT's first vehicle to have lithium-ion batteries and a carbon fiber body. It was completed in 2005 at a cost of $90,000. The solar array is made of 600 photovoltaic cells grouped in modules of 50, and split into three subarrays, for a total area of 8 m2. A maximum power output of 1200 W could propel it to a cruising speed of 45 mph and top speed of 55 mph.

It was entered in the 2005 North American Solar Challenge but could not compete due to poor weather and a steering malfunction. The team also entered Solar Steer into the North American Solar Challenge for 2006.

Samsung Solorean
Design began in early 2007 for UTSVT's next car, to be named after their sponsor, Samsung, and the DeLorean in Back to the Future. The chassis is chromoly tubular steel supporting the carbon fiber body. The battery pack consists of 598 LG 18650 lithium ion cells. The solar array is an assembly of 393 SunPower A-300 monocrystalline silicon cells split into three arrays able to produce up to 1.21 kW. A National Instruments CompactRIO controls all electrical subsystems. The motor is a New Generation brushless permanent magnet motor that can provide 3.75 kW of power at 95% efficiency while weighing 20 kg.

UTSVT completed Solorean June 2008, just too late to compete in the North American Solar Challenge that summer. Samsung Solorean competed in the 2009 and 2010 FSGP and 2010 American Solar Challenge.

TexSun
TexSun was completed spring 2013 at a cost of $140,000, $50,000 of which was donated by Circuit of the Americas. The three-wheeled vehicle has an aluminum space-frame chassis, carbon fiber body, and uses an Enertrac 602 hub motor to power the rear wheel. The batteries are lithium iron phosphate. It weighs between 500 and(-). The solar panels, mounted to a carbon-kevlar wing, provide a maximum of 1300 W. The car has a theoretical top speed of 60 to(-).

TexSun placed sixth at the 2013 Formula Sun Grand Prix held at Circuit of the Americas for the first time. It also participated in the 2015 and 2016 FSGPs, and competed for the last time at the 2017 FSGP the team hosted.

BeVolt
Production of BeVolt (portmanteau of Bevo and volt) began in the spring semester of 2017 to be race-ready for Formula Sun Grand Prix 2018. UTSVT again targeted summer 2019 for completion. The planned specifications for the car include a 4.8 kWh lithium-ion battery, a 4 m2 solar array producing 985 W, and two DC hub motors together good for 2 kW. The team designed for a weight of 160 kg for BeVolt by using a carbon fiber monocoque chassis and kevlar solar wing. This car fell behind schedule and was ultimately cancelled in 2020 following multiple manufacturing difficulties and the COVID-19 pandemic. BeVolt was budgeted at $180,000.

Lonestar
Planning of a new car began during the fall 2020 semester, with a goal to race during 2022. UTSVT designed their latest car, Lonestar, to weigh 600 lb and have a solar array of 260 cells that produces 875 W. Design work, finished in December 2020, was done predominantly virtually, with students spread far due to the COVID-19 pandemic. This also impacted manufacturing due to limited hours at J. J. Pickle Research Campus and some team members still working remotely.

The team brought Lonestar to the 2022 FSGP but could not race after technical inspection revealed an issue with the battery management system. The team will utilize the car as a test bed for the next car's development, which started summer 2022.

Daybreak
After Lonestar was found to have disqualifying issues, a new vehicle Daybreak was started in the summer of 2022. This vehicle is currently in development, is expected to complete by June 2024, and was unveiled in April 2024. It is slated to compete in FSGP 2024 and beyond.

Team leads
UTSVT's longtime faculty advisor is Dr. Gary A. Hallock, who has provided guidance since 2004. The team is led by captain Sidharth Babu, chief engineer Jacob Yan, mechanical lead Nathan Lee, electrical lead Manthan Upadhyaya, and controls lead Ishan Deshpande.