Role of PV generated DC power in transport sector: Case study of plug-in EV

Abstract

The challenge of meeting the corporate average fuel economy (CAFE) standards of 2025 is leading to major developments in the transportation sector, not the least of which is the utilization of clean energy sources. Solar energy as a main source of on-board fuel has not been extensively investigated. This paper reports on the usage of solar energy for transportation and investigates the extended driving range, the economic value, and the energy return of investment (EROI) of adding on-board photovoltaic (PV) technologies to plug-in electric vehicles (EV). The study develops a comprehensive PV system model and optimizes the solar energy to DC electrical power output ratio for on-driving mode. In times of no-use, the proposed system transforms into a flexible energy generation system that can be fed into the grid and used to power DC electrical devices in homes and offices. The results show that by adding on-board PVs to cover less than 50% of the projected horizontal surface area of a typical passenger EV, up to 50% of the total daily miles traveled by a person in the U.S. could be driven by solar energy. For the lifetime driving cost, even with low electricity price (0.13 $/kWh), adding on-board PV shows a positive impact if the system is operating in high solar energy environment (e.g. Arizona). If the electricity price is high ((0.35 $/kWh), there is positive economic impact even in low solar energy environments (e.g. Massachusetts). The energy payback time (EPBT) is found in a range 3.5-4.8 years, depending on where the system operates and energy return of investment (EROI) is between 6.2 to 8.6 times.