Toyota's plug-in hybrid PHV (photovoltaic hybrid vehicle) might have an upgrade. Recently, Sharp, Toyota and the New Energy and Industrial Technology Development Organization (NEDO) in Japan worked together on a new Prius PHV project. They upgraded the demo car to 34% ultra-high conversion efficiency PV panels. They plan for the demo car to go on public road trials by late July.
This project is led by NEDO. Back in April 2016, NEDO established the PV-powered Vehicle Strategy Committee. Its goal is to do researches to find solutions for the transport sector's energy issues and environmental problems in the transportation industry. The committee concentrates on PV power systems. The 3-company joint project team hopes to utilize the limited surface area of vehicles for installing PV power systems, and uses 30-plus percent efficiency PV panels to realize the 1 kW potential of power in vehicles.
Let's talk about the previous version of the Prius PHV. Prius PHV is a PHV-variation of Prius. In a Prius PHV, there is a general Li-ion charging system, and a number of 22% conversion efficiency solar panel with 180 W capacity. However, the previous version of the Prius PHV could only offer 6.1 kilometers of driving distance during sufficient sunshine. This capacity is far from enough.
In comparison, the 3-company team decided to use a different PV technology. NEDO used III-V semiconductor alloys, such as InGaP, GaAs, and InGaAs to develop 34-percent-or-more conversion efficiency triple-junction solar panels.
The newer version of PV panels (which are actually thin films) is only around 0.03mm in thickness. The panels are installed on the hood, roof, and rear hatch door of the Prius PHV. Then a demo car is made.
When the newer version solar panel is compared with the older version, there are 3 major differences. First, the solar energy conversion efficiency is significantly increased from 22% to 34%. Next, the power generation capacity has remarkably improved from 180 W to approximately 860 W when only the sun is used.
Third, the electric cruising range is increased a lot. In the previous version, the PV system only works for a parked car. However, in the newer version, the PV system not only works for a parked car, but it can also charge a car's battery when it is being driven. When a demo-car is still, the electric-only cruising distance can reach 44.5 kilometers. This figure is about 7 times higher than the previous Prius PHV model. In comparison, when a demo-car is being driven, the electric-powered cruising range can escalate to 56.3 km.
The next step is to do public road testing with the demo-car. In late July, the team plans to conduct trials with different driving conditions on local highways and freeways in Toyota City, Aichi Prefecture, and Tokyo. The testing will be finished by the end of February 2020.
NEDO, Toyota, and Sharp will share all of the data of the experimental trials. The data includes but is not limited to: how much CO2 emissions are deducted, how the number of times for charging is lowered, and the general public's acceptance levels.
As technologies of solar energy and EV advance, in the future, more innovative and interesting car models will be invented. Although their appearance or performance might not be able to compete against that of the traditional fossil-fuel cars, they are still noteworthy innovations. Earlier, it is worth noting that the Dutch EV startup Lightyear has also announced a solar-powered prototype car model called “Lightyear One” which is expected to offer 725 km of cruising range per complete charging cycle. The car will likely enter the mass production stage in 2021.
