BMW is working on resolving a dilemma faced by backers of fuel cell vehicles – where the hydrogen comes from.

The automaker is showing a 5-Series GT fuel cell prototype that has hydrogen coming from solar-powered electrolysis. It’s part of the 2017 Hannover Trade Fair in Germany.

The electrolysis process breaks the hydrogen down into two parts hydrogen, one part water. The only element that’s emitted is water, and the power source comes through solar-powered clean energy.

Most hydrogen is extracted through other sources besides solar, including petroleum and natural gas. That takes away some of the environmental benefits of producing hydrogen to run a vehicle’s electric motor.

BMW has taken a supportive, yet cautious, approach to endorsing fuel-cell vehicles. In 2013 the company entered a strategic alliance with Toyota to combines their research and development programs on this alternative powertrain and fuel.

BMW officials said that its goal now is to explore hydrogen fuel cell vehicles as another option in its portfolio of emissions-free mobility. The company is pitching the benefits of fuel cell vehicles in Hannover by boasting energy efficiency, fast refueling times, and longer range than battery-electric vehicles have been capable of.

It also supports the German automaker’s efforts on the solar energy front.

In 2014, BMW Motorsport forged a partnership with solar equipment supplier GermanPV. It was part of the automaker’s M4 DTM race sponsorship, with hints that it will be part of BMW’s electrification effort.

BMW conducted calculations on clean energy production with the Fraunhofer Institute for Solar Energy Systems ISE that demonstrate the benefits of using electrolysis. The energy can come from solar, wind, waves, or another alternative power source. The Institute says that going with a clean energy source supports the German government’s goal of hitting greenhouse gas reduction targets by 2050.

SEE ALSO: BMW Announces Partnership with Leading German Solar Company

Oil company Shell joined BMW’s Hannover display by demonstrating a hydrogen fueling pump. Shell developed the fuel dispenser with Designworks, a BMW subsidiary. They’re showing off how seamless it can be for fuel cell drivers to pull up and refuel in five minutes or less.

Shell is playing a significant role in bringing hydrogen fueling stations to Europe and the U.S.

BMW hasn’t laid out plans for commercializing fuel cell vehicles. Toyota, Honda, and Hyundai are taking the alternative powertrain seriously through production-level fuel cell vehicles. General Motors, Daimler, and Kia, along with BMW, are showing interest.

The Detroit Bureau