Hyundai is investing in a startup that plans to transport hydrogen in oil, potentially making use of existing fossil-fuel infrastructure.

The automaker is partnering with German startup Hydrogenious through its Hyundai Cradle division, which deals with emerging technology and startup partnerships. A deal was signed in May, but the partnership was recently spotlighted by startup accelerator Startup Autobahn.

Hydrogen is typically stored in gas form under high pressure. Hydrogenious proposes binding it to what it calls a Liquid Organic Hydrogen Carrier (LOHC), which the startup describes as similar to diesel fuel.

This allows hydrogen to be stored in liquid form at ambient temperature and pressure, Hydrogenious claims in the video embedded here. Hyundai also released a longer video with a bit more detail on the process.

That process is more efficient, because hydrogen can be stored at greater density when bonded to LOHC, the startup claims, adding that, the carrier oil isn't as flammable as gaseous hydrogen.

This also allows for continued use of fossil-fuel infrastructure to transport hydrogen, the startup notes, eliminating a major obstacle to mass adoption of fuel cells. 

However, that also means continuing to use fleets of oil tankers and tanker trucks—and much additional energy.

The Hyundai-affiliated investment isn't surprising, considering the company sees uses for hydrogen fuel-cell technology well beyond cars, envisioning a "hydrogen society" where fuel cells power commercial vehicles and are used to power buildings.

A report published in June estimated hydrogen could achieve price parity with gasoline by 2025, which could increase interest in fuel-cell cars and make other uses of fuel cells more financially attractive.

So far though, lack of infrastructure has limited sales of the Hyundai Nexo fuel-cell SUV to certain areas of California. It's the same story with the Honda Clarity Fuel Cell and Toyota Mirai, the only other fuel-cell passenger cars currently available in the United States.

Nikola plans to build a network of hydrogen stations for its planned fuel-cell semi trucks along major highways, but the company hasn't built a single station or vehicle yet.

Making hydrogen from renewable energy, then transporting it with trucks, in oil, could create a new, confusing twist to how some types of transportation are getting their energy.