A comparison among various parameters (yield, financial cost, environmental cost) of various vectors: hydrogen, compressed air and the battery.

The installation structure includes 3 corridors reaching a model representing a city with various, movable bus-models. Each corridor represents a selection: battery, compressed air, hydrogen. The costs: yield, environmental cost, financial cost are represented by a coin-slot.

The visitor receives 10 coins from a coin machine, representing the “resources units” available. According to the corridor selected, the visitor will face a series of costs; the remaining coins will power a longer or shorted bus journey.