Webasto predicts major gains for high-tech roof systems

Stockdorf, GERMANY -- Webasto looks at cars the way a hammer looks at a nail.

“At Webasto our feeling is that a car without a roof that opens is not complete,” said Jan Henning Mehlfeldt, a member of the supplier's board of management.

The German supplier, which already has an estimated 48 percent share of the global passenger car roof systems market, will showcase products it expects to be fitted into the vast majority of vehicles in the near future at the IAA Mobility show in Munich next month.

Webasto executives provided Automotive News Europe a preview of its systems in Stockdorf, southwest of Munich, ahead of the show, which starts Sept. 4.

Maximilian Hofbeck, Webasto's director of product management, said the company expects that 80 to 90 percent of future vehicles will have roofs with ambient lighting and segmented switchable glazing. Webasto, which will start series production of roofs with both features in 2025, wants to capitalize on this trend.

Currently, many of today's systems are on high-end cars with panoramic roofs that don't slide open, but Mehlfeldt said the products will trickle down into more affordable segments and that Webasto will integrate these technologies into roofs that open.

"This is not just for a Rolls-Royce and Maybach but for all other carmakers with a range of different customers," Mehlfeldt said.

When ask about the cost, Mehlfeldt said for the supplier upgrading to a slide panorama roof with ambient lighting or switchable glazing is a 20 percent premium on a traditional system.

Solar solution

The supplier also will use the Munich show to display what it says is the world's largest openable solar roof. Webasto already has a customer for its solar roof but Mehlfeldt could say only that it will be used by a "California brand."

That solar-powered solution has 50 cells with a 300-watt peak performance.

"The customer says that as long as the car gets enough sunlight and is parked outside, the solar panels will provide an extra 3,000 km (more than 1,850 miles) of driving a year," Mehlfeldt said. "It’s not just about range. With this you can show your ambition to create a green statement. It’s not a gimmick. It works and provides some benefit."

Solar roofs can be made up of solid cells that are not transparent, while another option is to use a semitransparent pattern in which it will be possible to see through the space between the cells.

The price premium for a solar roof is also about 20 percent, said Mehlfeldt, who joined Webasto from Faurecia in 2011 as the company's head of purchasing and supplier quality and served as president of the supplier's China business from 2019-22.

Autonomous cars with open tops

Webasto will also use the IAA to showcase its so-called Roof Sensor Module, specifically made to work with vehicles that will have Level 4 or higher autonomous driving capability. The supplier's aim is to ensure that self-driving cars will not have to forgo a sliding glass roof.

The prototype roof system has 14 different sensors, including lidar. Webasto sees itself as the integrator that makes sure the software and sensors work together with the hardware.

"We will look after how to clean and cool and de-ice those sensors, making sure that they function at all times," Mehlfeldt said.

Webasto is convinced that the roof is the best place for all of the vision system that autonomous cars will need because the height provides a wider view of the road; its easier to keep that part of the car clean than the bumpers and that area is less likely to get damaged in a accident.

That being said, Mehlfeldt said there is a difficult hurdle to overcomes. The prototype's system will accommodate a lidar sensor that is a maximum of 5 cm (2 inches) tall and today's solutions are 10 cm or taller.

"We are confident that we the next generation of lidar sensors will fit in this type of roof system," he said. "And what is really unique about the roof system is that it opens."

When it comes to cleaning the sensors, Webasto plans to use water as well as pressurized air.

"Air is less complex [than using a water]," Mehlfeldt said, "and sometimes all you need is a blast or two to clean off the sensor."