Hydropower is a crucial cog in Switzerland's energy mix. It is the country's "most important domestic source of renewable energy" and worth around 1.8 billion Swiss francs ($1.85 billion), according to the Swiss Federal Office of Energy.

One business is looking to harness this abundance of Swiss hydropower to produce hydrogen. H2 Energy, together with IBAarau, has been working on the installation of a hydrogen generation plant at a hydropower facility in Aarau, in the country's north.

The facility is described by H2 Energy as the first electrolyzer plant in Switzerland that produces hydrogen from renewable energy.

The method of producing hydrogen at the Aarau site can be broken down into several parts: when electric power is produced at the hydro facility, it is sent to an electrolyzer. This uses electrolysis to "split" water, producing hydrogen and oxygen.

"After the hydrogen has been produced, it is directly… compressed in a trailer," H2 Energy's Rolf Huber told Sustainable Energy. The hydrogen is then transported to a hydrogen fueling station, he added. "This technology is especially good for the environment because hydrogen has no emissions other than water."

H2 Energy says the facility will generate enough hydrogen for the annual fuel consumption of around 170 fuel cell cars.

There are specific environmental benefits related to powering a vehicle with hydrogen.

According to the U.S. Department of Energy's Alternative Fuels Data Center, fuel cell electric vehicles powered by hydrogen represent a more efficient option than internal combustion engines. In addition, they don't produce "harmful" tailpipe exhaust, emitting warm air and water vapor only.

"With this project we have demonstrated that not only the hydrogen production is economically viable but also, technically, it works," Huber said.

"This is not a demo project, this is an economic, viable energy cycle," he added. "We use the hydrogen and allow a complete substitution of diesel, heavy duty vehicles, with hydrogen technology."