An extremely efficient solar-powered car with a range of up to 725 km without having to stop at a charging station. The Dutch start-up Lightyear is currently testing the first prototype. The sealing technology developed by Exypnos, based in Kruibeke, Belgium, played an important part in getting this first-in-class vehicle on the road.


In 2013, Johan Van Dyck and Stijn Langie – now CEO and Technology & Development Manager – founded Exypnos as a spin-off of the chemical giant BASF. Eight years earlier, they witnessed the birth of Window Spray Technology (WST), an innovative procedure for pressureless application of polyurethane to glass in an open mould, seamlessly bonding various components together to achieve waterproofing. Exypnos is now the market leader in Europe and China, having developed WST applications for the construction, energy and automotive industries.

Specialists in light, seamless encapsulation and bonding

Lightyear – a Dutch start-up with a mission of expanding the market for long-range solar-powered vehicles by 2021 –launched a pilot project this year with two new models. Lightyear counted on Exypnos’ expertise and experience to build one of these models, a Tesla 3 with solar panels on its roof.

“We remove limitations caused by sealing or anchoring for designers”, said Johan Van Dyck. “We have develop framing technology to integrate solar panels into the roof of a car. Watertightness is guaranteed without compromising aesthetic values. Lightyear was enthusiastic about the solution and selected us as a partner for this innovative project. We are very proud to be working with them to pave the way for solar-powered cars.”

Efficiency to the power of three

The fear of being stranded with a flat battery – ‘range anxiety’ –is one of the major obstacles to customers buying an electric car. In recent years, a few models with batteries with a higher capacity and therefore more range have been launched, but the prices go with that.  

Johan Van Dyck: “Efficiency is a stumbling block these days. A battery with more capacity is heavier, meaning the car consumes more energy. Heavy-duty batteries are also more expensive than smaller ones.

Integrating a solar panel into a polyurethane frame on the roof of a car roof is more efficient in three ways:

  • The built-in solar panel ensures the battery is charged when driving. The range is therefore higher than that of a car that can only be charged from a power outlet.
  • Car manufacturers can use a smaller battery, loweringtheprice for the consumer.
  • The car is much lighter with the use of a smaller battery in combination with solar panels, so energy consumption decreases.”

Considerable interest

The application of ‘vehicle-integrated photovoltaics’ has generated widespread interest, including from other car manufacturers. Johan Van Dyck: “We have already pitched the technology to a few major car brands. We hope they will jump on board to make solar-powered cars a fully-fledged alternative to their current models with an internal combustion engine. Bus and lorry manufacturers are also showing interest in this technology.”

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