Advantages of a flexible operating system demonstrated on a photovoltaically powered bus stop shelter

The high costs of connecting isolated bus stop shelters to the public electricity grid have meant that most of them are unlit. However, in these areas remote from the grid, where there is little or no other form of lighting, illumination of the bus stop shelter would be a particularly valuable improvement for the public transport user. The timetables can be read and the person waiting usually feels safer in an illuminated shelter. Nowadays, photovoltaics presents an economic alternative to supply energy to these remote locations. The disadvantage of this decentralised power supply is the control unit needed in each shelter to control the lighting. If the conventional timer technology is used, the configuration of this control unit according to the insolation conditions and the consumer requirements, is very complicated and unsatisfactory. A flexible operating system can adjust itself automatically to the true local time, and allows switching cycles corresponding to the user specificati ons and energy storage conditions to be implemented. The value of the bus stop shelter is raised, the component lifetimes are extended and the amount of maintenance is minimised. As part of the BMFT-funded programme, "Photovoltaics in the medium and low power range", ISE has developed a flexible operating system for PV powered lighting systems, in close cooperation with the industry. This system will be presented in detail in the following paper.