The global and local impacts of climate change have increased the interest in decarbonizing energy economies in general and transportation in particular. Solar EVs represent an intersection of renewable energy generation and EV development, both of which are topical focuses of current research in their own right. Mirroring the rise of automobiles and aviation, many of the developments in solar EVs have come from competition-based innovation. The development of complex electromechanical systems has been assisted in recent years by the use of digital twins, which are built on physics-based models of the underlying systems. This research develops a digital twin based on a solar electric racing vehicle constructed by Appalachian State University. The digital twin consists of two interlinked models, with the first representing a 1-D model of the vehicle dynamics, electric motor, and race course. The second represents the solar panels and battery system, with the current draw on the motor linking the two models. In combination, the digital twin is driven by a variety of inputs such as motor parameters, course elevation, vehicle dimensions, battery parameters, and solar panel configuration. The key outputs from the digital twin are the vehicle speed, current draws, and SOC for the battery. In simulating the performance of the digital twin on a variety of virtual tracks, all of these outputs are critical in the rapid development of a more competitive race vehicle and strategy.