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Following is a question by the Hon Chan Hak-kan and a written reply by the Secretary for Transport and Housing, Professor Anthony Cheung Bing-leung, in the Legislative Council today (February 25):
Question:
Regarding the public lighting system in Hong Kong, will the Government inform this Council:
(1) of the years in which the various types of streetlights (including those for carriageways and footpaths) currently in use in Hong Kong were designed and their respective luminous efficiency, with a breakdown of the number of each type of streetlights by District Council district;
(2) of the electricity consumption of streetlights and its percentage in the total electricity consumption in Hong Kong, as well as the public expenditure on the repair and maintenance of streetlights, in each of the past three years;
(3) as the Public Lighting Design Manual has not been updated since 2006, whether the Government has plans to update the Manual in the near future; if it does, of the details, if not, the reasons for that;
(4) as some western countries (e.g. Denmark) have plans to replace their existing old-fashioned carriageway lighting systems and gradually introduce intelligent lighting systems (e.g. street lighting systems with motion sensors to dim the lights automatically when no vehicles are running on the roads) in order to save electricity, whether the Government has plans to introduce similar systems to roads/streets with lighter vehicular/pedestrian flows; if it does, of the details; if not, the reasons for that;
(5) of the current number of streetlights in Hong Kong equipped with devices using renewable energy (e.g. solar power and wind power) to generate power; whether the authorities have plans to install such devices for more streetlights; and
(6) of the number of complaints about streetlights (e.g. nuisance caused by street lighting) received by the Government in each of the past three years?
Reply:
President,
The Highways Department (HyD) is responsible for the design standards, operation and maintenance, as well as the majority of design and construction of the public lighting system in Hong Kong. The public lighting system is an auxiliary facility of the road network, and needs to be properly managed and continually enhanced in order to provide the community with reliable, safe, environmental-friendly and cost-effective public lighting. In general, public lighting facilities can be classified into road lighting and special lighting. Road lighting includes carriageway lighting, footpath lighting and cycle track lighting. Special lighting includes underpass lighting, highmast lighting, highbay lighting at public transport interchanges, footbridge and subway lighting, gantry sign and roadside directional sign lighting, traffic bollards, etc.
Since the 1990s, high pressure sodium lamps, which are of higher efficacy, have been widely adopted in the road lighting in Hong Kong. The efficacy ranges from about 90 lumens per watt (W) for low wattage ones to 150 lumens per watt for high wattage ones, both exceeding that of household compact fluorescent lamps which is about 60 lumens per watt. The adoption of these high pressure sodium lamps has resulted in an energy saving of about 30 per cent as compared with the road lighting equipment used in the past. The HyD has been keeping abreast of the technological development of different types of lighting systems in the market and trialing new energy-efficient road lighting products, including ceramic discharge metal halide lamps and light emitting diode (LED) lamps.
Besides trialing the above-mentioned road lighting products, the HyD also attaches importance to the energy-saving requirements of public lighting. Since 2005, the HyD has been progressively switching over to T5 tubular fluorescent lamps of ratings from 14W to 35W for replacing the old T8 tubular fluorescent lamps at footbridges and subways.
The reply to the six parts of the Hon Chan Hak-kan's question is as follows:
(1) For the information about the different types of road lamps currently adopted in Hong Kong, please refer to Annex.
(2) From 2012 to 2014, the annual power consumption of road lights in Hong Kong was about 0.1 billion units (one unit of power consumption equals 1 kilowatt hour (kWh)), which is about 0.24 per cent of the total annual power consumption of Hong Kong. In 2012, 2013 and 2014, the annual expenditures of the HyD on the repair and maintenance of road lights in Hong Kong were about $81.3 million, $85.5 million and $92.4 million respectively.
(3) The Public Lighting Design Manual (Manual) was compiled by the HyD in 1996 as the design standard on different aspects of the public lighting system in Hong Kong, including the specifications for lighting equipment (such as lamps, lamp posts and cables), operational conditions, illumination levels, etc. The HyD regularly reviews and updates the contents of the Manual in view of the latest developments of the relevant international lighting standards and the needs of the actual road conditions in Hong Kong. The last revision was in 2006. The HyD is now reviewing and updating the contents of the current version of the Manual with a view to completion in 2016.
(4) It is learnt that some western countries are trialing a smart lighting system on some roads in remote areas with few vehicles and people. Road lights will be dimmed when there are no vehicles or people on the roads in order to save power consumption. However, the system requires plenty of sensors and monitoring devices to be installed on the roads, resulting in a significant increase in the capital cost as well as repair and maintenance cost of the lighting system. Moreover, as the system is still on trial, there is inadequate data for analysing cost-effectiveness and reliability. Neither is there any internationally recognised standard for observance.
The population density of Hong Kong is high. Roads of different classes are used by a number of vehicles and people even late at night, considerably constraining the possible time to have road lights dimmed. Moreover, some road users find it necessary to have sufficiently illuminated roads to ensure traffic and pedestrian safety as well as to meet security needs, thus having reservation about the dimming of road lights. The HyD does not have any plan to adopt this kind of smart lighting system at the moment, yet will closely monitor the application experiences of other countries and the relevant technological development. The HyD is also arranging a trial of a similar dimming system at some footbridges with relatively low pedestrian flow to ascertain the public acceptance and cost-effectiveness of the system.
(5) There are 17 stand-alone solar road lights installed by the HyD in Hong Kong at present. All of them are located in remote areas where normal power supply is unavailable. Application of renewable energy in road lighting has its limitations. As a large number of batteries are required to store the energy collected in daytime for use by road lights operated at night time, the repair and maintenance cost will be significantly increased. Moreover, the roads of Hong Kong are so densely built that there is not sufficient space for installing facilities for collecting and storing renewable energy. Buildings closely surrounding the roads also block sunlight and wind, making it not suitable to install a renewable energy system on urban roads. Under a trial scheme, the HyD has recently installed a photovoltaic panel of about 200 square meters large on a noise barrier at Fanling Highway to provide solar power for 16 road lights nearby with the mains electricity (i.e. the electricity provided by the power company) as backup power supply. The HyD will monitor and assess the effectiveness of the trial scheme to study whether renewable energy can be further promoted in the public lighting system in Hong Kong.
(6) In 2012, 2013 and 2014, the HyD received 11 332, 10 199 and 10 348 complaints about road lighting respectively. Over 96 per cent of the complaints were related to road light fault or damage.
Ends/Wednesday, February 25, 2015
Issued at HKT 14:00
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