Hydro

Hydro (otherwise known as "Hydrogen burner") is a Streetslang term used for Hydrogen fuel, a fuel source used to power vehicles.

Hydro Quotes
Computer down? No Problem. Hydrogen burner out in your Metro car?

2013s
During the earlier part of the 2000s there was a sizeable number of Hydrogen Fueled vehicles introduced, but CHOOH2 remained in the number one spot.

2020s - 2030s
After the early 2000s Hydro has become a competitive choice to the electrically powered and CHOOH2 powered vehicles.

2045s
In they mention that Hydro used to power a small amount of vehicles in the 2020s and 2030s. This means in the 2045s Hydro has become a lesser used fuel source, The collapse of Night City probably de-valued the use of alternative fuel sources and encouraged more CHOOH2 powered vehicle sales.

Although contradicting the last statement, there's a huge number of bikes, trikes, cars and speedboats out there these days powered by Hydro. Maybe Hydro production was still successful in other countries that were more environmentally conscious.

2201s
Hydrogen production has never been beter, in the 23rd century petroleum and CHOOH2 have almost run dry. Methane, Electricity and Hydro now lead the charge in vehicle powered systems, each country specialises in the fuel sources it has the most readily available.