The Idea of a solar-powered vehicle or Vehicle Integrated PhotoVoltaic (VIPV) is nothing new. Dates back to the 31st of August in 1955 when William G. Cobb, a GM engineer revealed the world’s first VIPV prototype at the General Motors Powerama auto show held in Chicago, Illinois. “Sunmobile” was the name of his 15-inch long tiny automobile, which included 12 photovoltaic cells made of selenium ( a nonmetal substance with conducting properties) to power up a tiny motor that was connected to its rear axle by a pulley. However, the key idea behind that was NOT creating something clean and green which could help to mitigate the environmental effects of diesel cars, as it was not considered a threat at that time. He wanted simply to show us the feasibility of the idea to run cars with solar energy.
Currently, there are several companies like Sono motor (Sion), Lightyear (Lightyear One), Hyundai (Sonata), and Tesla (Cyber Truck), that are trying to use this approach to either extend their range or to be able to fully charge your vehicle.
Using photovoltaics can be achieved in a couple of ways; by charging stations that are solar-powered or by photovoltaic modules which are built-in to a car’s body parts, (VIPV).
The reason for the increase of interest in VIPVs is due to the increase in efficiency of solar modules, decrease in the prices of solar modules, and the booming market of hybrid or electric vehicles.
If all of the electric vehicles by the year 2030 were equipped with a solar roof and assuming those vehicles had an average roof area of 2/m² and a solar module with the capacity of 200 W/m², they would have a potential market of 18GW per year.
The potential solar range differs greatly from vehicle to vehicle due to overall design and the bigger the surface is the more potential solar range.
In this test, only roof area was considered because of its simpler technological implementation, manufacturers have already implemented this idea, and the yield on the roof of the car is potentially the highest relative to other parts of the vehicle.
This puts the potential solar range at 1900 and up to 3400 km per year. This amounts to 13-26% of the average yearly driving distance (15000km) of a car in Germany, considering that all of the power generated by the modules to be only used for propulsion.
Also if solar modules are installed on normal electric vehicles in the Netherlands, it is expected to have about 25% fewer times charging annually, and in summer you may even drive for three months without recharging the vehicle a single time. In sunny places like Spain and Italy, the charging time might even reach 40% with the current technology annually. Also with three-to-four-year payback time, there is a reasonable benefit to be considered.
The placement of solar modules is also an important part due to health, durability, and safety requirements. Right now solar modules are mostly used on the roof (Integration level 1) and some on their hood (Integration level 2).
Integration level one is just a little different than a glass module. In integration level 2 (hood and trunk) because of requirements regarding safety, durability (i.e. scratch resistance), and curvature, it is harder to achieve and needs new module technologies to be applied.
In the unfortunate incident of a crash, solar modules can shatter and endanger rescue workers, pedestrians, as well as passengers.
The limited space availability on commercial passenger vehicles and subsequent lower power generation could hinder its usage.
The yield reduction because of shading also should be discussed. This depends on the location of the vehicle, the driving pattern, and the time of the year.
As of now the feasibility of a fully solar-powered vehicle that is able to traverse great distances is very low. It is possible to use a fully solar-powered vehicle for short distances and there are some options on that front as well, like Sion from Sonomotors which according to them can add up to 245 km (112 km on average) of driving range per week through solar energy to the car’s battery.
Also, the body of a vehicle has limited space to accommodate solar panels, and until their efficiency is not increased they are not suitable for traversing long distances without any other source of energy, and for it to work with high efficiency, certain weather and climate conditions should be met as well.
Right now one of the feasible ways to use vehicle-integrated photovoltaic is to use them as a secondary source of power so they could be charged with both electricity from the grid or charging station and also with solar energy. This in turn will also benefit the driving range of the vehicle.
As of now, there aren’t many VIPVs out there, but because of advancements in solar technology in regards to efficiency and lowering of module prices, there is scope for further development and growth. This market also has great potential, reaching about 18 GW annually.So much that by 2030 10% of electric vehicles could be represented with VIPVs. Especially in sunny condition, it is possible to drive for weeks without charging.