Effectiveness and Issues of Automotive Electric Power Generating System Using Solar Modules

Solar and other green energy technologies are attracting attention as a means of helping to address global warming caused by CO2 and other emission gases. Countries, factories, and individual homes around the world have already introduced photovoltaic energy power sources, a trend that is likely to increase in the future. Electric vehicles powered from photovoltaic energy systems can help decrease the CO2 emmissions caused by vehicles. Unlike vehicles used for solar car racing, it is not easy to equip conventional vehicles with solar modules because the available area for module installation is very small to maintain cabin space, and the body lines of conventional vehicles are also usually slightly rounded. These factors decrease the performance of photovoltaic energy systems and prevent sufficient electric power generation. This research aimed to estimate the effectiveness of a solar module power generating system equipped on a conventional car, the Toyota Prius PHV. Sixteen modules were set on the hood, roof, hatchback, and sides of the car. The energy from each module was controlled by maximum power point tracking (MPPT) unit, a system used to reduce the energy loss caused by differences in solar radiation among the modules. Electric power generation data over the course of 100 days from July 1 to January 30 in 2014 found that the modules generated an average of 2.0 kWh/day. This is equivalent to a driving distance of 9.8 km. At the same time, this research also identified various problems related to increasing the electric power obtained from photovoltaic modules.