Hybrid Air concept car

Citroen C3 Hybrid Air - compressed air engine

The Citroen C3, powered by compressed air, was made into a cut-away concept car to show off the features and where the air storage system is fitted.

Hybrid

The air-powered Citroen C3 concept car was shown at Geneva Car Show 2013. It had a petrol engine and a compressed air source. The idea is similar to the current hybrid cars with petrol and electric, where the petrol can assist or be run on cleaner fuel in cities and towns or the petrol-only mode when the air tank is depleted.

Emissions

Compressed air is an energy store that can be used for town driving that requires cleaner emissions. There is regenerative braking, and the petrol engine can run the air compressor to recharge it.

Generally, the whole system is much cleaner than batteries because there are no chemicals like lithium to be mined to produce the batteries, and the end-of-life for the compressed air fuel cell is much easier to deal with.

Safety

With safety concerns for the compressed air and longevity concerns to overcome, the investment wasn't available to produce the new vehicle-use technology.

Storage Tanks

Two additional locations for the storage tanks were required. The rear petrol tank area shares space with the compressor oil tank at the car's rear. The compressed Nitrogen tank is a cylindrical container in the transmission tunnel.

Engine

• 81 bhp petrol unit

• 120 total horsepower output

System

The video shows how the system was expected to work, switching between air-powered petrol engines and energy recovery modes.