A natural gas bus works the same way as diesel and petrol vehicles: with a piston engine and internal combustion. The natural gas is stored in tanks, which can be stored on the roof. But unlike diesel, petrol, and bottled gas, natural gas is not a liquid. To store a sufficient amount of energy, the natural gas is compressed to a high pressure of approx. 200 bar.

Quickly refuelled at a filling station or slowly overnight
The natural gas is compressed at a vehicle filling station. The filling stations work as typical public petrol stations. Refuelling takes just a few minutes. The filling connecting piece is put in place with a lever which ensures a safe and tight connection. 

For commercial use, there are also slow filling stations where a bus can refuel overnight when it is parked. There are also corresponding home filling stations for use at private homes.