The costs of a Betalux escape route markings are zero, they do not absorb any electrical energy. Since the escape route signage is not connected to the mains, you save considerable costs on your electricity consumption. You could not wish for better energy savings. For this reason, they have been used in airplanes for many years. The principle is simple, there are tubes filled with Tritium gas in the escape route signage. This gas has the property that it activates the fluorescent layer, so that the tubes emit a soft light. Continuously, without interruption. Even if the power fails for a longer period of time. For the sake of clarity, only the sign is illuminated, so it is not emergency lighting as you often see with the usual combination luminaire escape route signaling / emergency lighting.