Energy
Conservation

To meet accessibility requirements as laid down in the Design Manual: Barrier Free Access 2008 promulgated by the Buildings Department, the illumination standard for public areas has been increased to accommodate people with special needs such as those with vision impairments. To achieve this standard without increasing energy consumption, a two-level lighting control system has been adopted in new domestic block designs since December 2008. The system allows users to adjust lighting levels as needed. The illumination levels for public areas are as follows:

Public Areas of Domestic Block	Normal Mode	Triggered Mode
for typical lift lobby	50 lux	85 lux
for typical corridor	30 lux	85 lux
for staircase	30 lux	85 lux
for ground floor lift lobby	120 lux	NA
for lift car	150 lux	NA

For fluorescent type lighting fittings, about 20% of electrical energy could be saved if electronic ballast is used instead of electromagnetic ballast. In view of this, since 2003, we have widely adopted the use of electronic ballast. At present, all fluorescent type lighting fittings are equipped with electronic ballasts.

Starting from 2012/13, we have launched a 42-month programme of replacing existing light fittings equipped with electromagnetic ballast by energy-saving electronic ballast in communal areas of all our existing estates, covering around 960 domestic blocks. The replacement work for all 960 domestic blocks have been completed in September 2015.

To increase energy efficiency, HA has adopted LED lighting in new developments. Since early 2016, LED bulkheads have been the standard luminaire for communal areas in new domestic blocks. HA has also adopted LED exit signs, directional signs, and tubular lamps in new projects starting in 2019.

For existing PRH blocks, starting from 2019/20, LED bulkheads have been adopted in communal areas to replace defective public lighting. Besides, LED exit signs and directional signs are also used to replace the conventional ones.

To improve energy efficiency, HA have adopted variable speed drive control for the fresh water booster pump system in all new projects. Together with smaller stainless steel pneumatic pressure vessels, the system could achieve higher energy efficiency and occupy less plant room space.

To improve sustainability, HA has adopted innovative HVAC systems in some new developments. For example, hybrid ventilation and free cooling systems at shopping centers combine natural and mechanical ventilation to reduce energy use. By switching between ventilation modes based on users’ need, these systems decrease energy consumption and hence carbon emissions. HA will consider using this system in other appropriate projects in accordance with relevant guidelines.

HA has adopted innovative technologies such as district cooling systems (DCS). The PRH developments at Kai Ching Estate and Tak Long Estate developments use a centralized DCS provided by the Electrical and Mechanical Services Department (EMSD) to supply chilled water to air conditioning systems for non-domestic facilities including shops, kindergartens, and estate offices. Through centralized cooling, the DCS can save up to 35% more energy than conventional systems.

HA has adopted energy-efficient technologies for lifts. These include permanent magnet synchronous motors, regenerative drives for high-power motors, and gearless/machine-room-less lifts. These technologies increase energy efficiency and reduce space requirements. By utilising these technologies, HA is working to create greener public housing.

To encourage sustainable living, HA has adopted technologies that provide energy usage information to residents. The Smart Meter Monitoring and Energy Information Display System comprising smart meters and displays that show electricity, gas, and water consumption for blocks in the estate at the main entrance lobbies. The displays facilitate comparison of energy use between blocks, raising awareness of conservation opportunities. By providing transparent data, the system helps residents understand and reduce their environmental impact. Through initiatives like this, HA is working with residents to build a greener community.

To promote the use of renewable energy in line with Government’s policy, HA has incorporated photovoltaic (PV) systems into public rental housing blocks where technically feasible since 2011. New rental housing blocks have included grid-connected PV systems that generate renewable electricity for communal areas providing 1.5-2.5% of communal electricity needs. HA continues to explore and pilot new renewable technologies in public housing. Through the use of clean energy, HA is working to make Hong Kong's public housing more sustainable.

For existing PRH estates, HA completed the first trial project of flexible PV system at Kwai Shing West Estate at the end of 2021. Afterwards, it is planned to install flexible solar PV systems at about 25 existing PRH estates progressively by the first quarter of 2024.

• PV Systems

  A pilot grid-connected mono-crystalline silicon PV system at Lam Tin Estate has been in operation since August 2009. It could feed in certain amount of renewable electricity to the electricity grid.

  In view of the satisfactory performance of the pilot PV system, the HA decided in 2011 to implement grid-connected PV system in all new public rental housing developments to feed in renewable electricity equivalent to about 1.5% to 2.5% of the electricity demand of the building communal area of each domestic block to the electricity grid as far as practicable. Meanwhile, we will continue the search and piloting of other renewable energy technologies for application in public rental housing estates.

  

  Grid-connected photovoltaic systems