Volvo Group’s venture capital arm has invested in company  that is at the forefront of large scale wireless charging. The company is Momentum Dynamics and its  wireless chargers already keep buses running around the clock in several U.S. cities.

Wireless charging allows any type of vehicle to automatically connect to the electrical power grid without wires or cables. The charger, buried below ground or mounted to a parking surface, connects with a receiver mounted under the vehicle.

“Momentum Dynamics’ technology and competence within inductive bidirectional transmission of electrical energy and information safely through air, water and ice will fit the harsh conditions under which our customers operate,” said Per Adamsson, vice president at Volvo Group Venture Capital.

Neither Volvo nor Momentum Dynamics would discuss how much Volvo invested.

Volvo said in December it would produce an electric version of its VNR heavy-duty truck in 2021.

Volvo is exploring infrastructure options “within the ecosystem around electric transportation and energy supply,” said Stefan Söderling, investment director at Volvo Group Venture Capital.

A recent report by the British analytics firm Interact predicts global sales of slightly more than 4 million battery-electric, plug-in hybrid and conventional hybrid trucks through 2025. Light and medium-duty models will account for most of them.

Paccar’s DAF, has partnered with VDL Group and Cummins to electrify its CF and LF trucks. Freightliner, Daimler Truck’s U.S. brand, recently delivered the first eM2 medium duty electric truck  to Penske Truck Leasing. Paccar’s Peterbilt Motors division last week unveiled a new medium duty electric chassis for regional freight, delivery and refuse truck use.

Momentum Dynamics, a privately held 10-year-old suburban Philadelphia company, said wireless charging has applications for all types of trucks, beginning with delivery and medium-duty trucks that operate on the same routes.

Heavy-duty trucks that sit for long periods waiting to pick up loads from ports “should be charging while they are waiting,” Andrew Daga, chief executive of Momentum Dynamics, told

“The entire industry has neglected the idea of how to fuel (electric) vehicles,” he said.

In local delivery, wireless charging avoids having to train package handlers how to plug in and remove chargers from electric trucks.

“They forget, or do it improperly, or drive away still plugged in,” Daga said.

Momentum Dynamics has provided 200-kilowatt wireless charging systems to bus systems in three American cities Chattanooga, Martha’s Vineyard and Columbia. Buses charging during longer stops have enough energy to operate for 24 hours straight, Daga said.

A wireless charging system costs about the same as a plug-in charger. But wireless costs less to operate because it has fewer parts that wear out. Momentum Dynamics claims 94.7 percent charging efficiency.

Direct charging plug-in systems lose efficiency over time because they more power conversion stages than wireless. Insulation cables wears out, leading to cracks, and spring-mounted reels are expensive to replace, Daga said.

Truck companies “don’t want to add new maintenance cost of any kind,” he said.