While fully electric or electrified vehicles have firmly established themselves as the future of the automobile, a lot has still to be achieved in optimizing battery technology and expanding charging infrastructure. There have been significant advancements in these areas over the past few years, but it will still take some time for these to be able to match the convenience of fuelling up at a petrol station.  In the interim, many brands have tried different ways of augmenting the battery capacity and range of their vehicles, albeit to very modest levels.

Toyota, which has been a pioneer in petrol-electric hybrid technology, has been experimenting with solar power to add to battery power, offering a solar roof option in their Prius a few years ago. However, this arrangement could only bring about a minor improvement to the car’s range, as it generates just 180 watts adding a meagre 6.1km to the battery-only range a day.

Now, the Japanese carmaker, in collaboration with New Energy and Industrial Technology Development Organization (NEDO) and Sharp Corporation, has fitted a Prius with a solar kit that’s capable of charging the vehicle while it is on the move. The onboard solar battery panel developed by Sharp is installed on the roof, hood, rear hatch door, and other parts a demo Prius. This car will undergo rigorous public road trials starting from end of this month to assess its efficiency. The rated power generation output is around 860 W, which is approximately 4.8-times higher than the commercial Prius with a solar charging system and the battery-only range of the demo car will be a much more useful 56.3 km. The demo car also employs a system that charges the driving battery while the vehicle is parked and also while it's being driven, a development that will lead to substantial improvements in electric-powered cruising range and fuel efficiency.

Toyota plans to conduct the trials under various driving conditions in Toyota City, Aichi Prefecture, Tokyo, and other areas. Various data, including the power generation output of the solar battery panel and the levels to which the drive battery is charged, will be obtained and verified, and then used in the development of an onboard solar recharging system for production use. Toyota says the goal is to contribute to the creation of a new solar battery panel market, including for the transport sector, and find solutions for wider energy and environmental issues.