Management of public lighting

Thomas D. Baenziger, Merloni Progetti, Italy

Keywords

lighting control systems, lighting management systems for public lighting, systems to reduce lighting during low traffic hours, communication and information systems for public lighting distribution boards and for individual lighting points

Abstract

Public Lighting Consumes a lot of Energy!
About 5 % of energy used in lighting is consumed by public lighting. Energy for public lighting is the biggest part in the energy usage of a town and the maintenance and operation of the lighting is a considerable expense for every city.

Telemanagement
It is therefore important to allocate resources most efficiently and make use of the technologies available today. Dimming Technologies for HID lamps and not to a lesser extent communication technologies such as power line carrier and GSM telephone play an important role. Communication to the distribution board and even to each individual lighting point is used today. The data collected is stored in a database and managed by a central control station essentially consisting of a PC. Not only the proper operation of an individual lighting point is monitored. Information such as luminaire voltage, lamp current, capacitor current, and power but also each individual lamp voltage is recorded and analysed. The lamp voltage in particular gives us an important information about the state of the lamp itself and so we can predict a lamp failure months before it actually occurs. This means lamps can be changed before they fail and the lighting can be guaranteed to a very high degree. Safety and security is guaranteed for the users of public spaces.

Dynamic Public Lighting
A recent three-year study by the transport and public works department in the Netherlands tested the concepts of reduced luminance during low traffic hours and under good metrological conditions. It concluded that the concept of dynamic public lighting should be used. A similar conclusion can be found in the new European Standards for public lighting. Luminance levels can be reduced by as much as 50% under favourable conditions. Considerable energy savings are achieved (30% - 40%) and due to the proper operation of the lamps (no over voltage) the service life of the lamps is extended.

Systems Pay for Themselves
Because of the energy and maintenance savings systems pay for themselves within 3-5 years. They can be installed on a energy performance contract bases (ESCO) without using financial resources elsewhere needed.

This paper shall discuss the technologies available, use of forecasting techniques, the various benefits to be derived from management systems.