For discussion
on 29 March 1999


Innovative Energy Efficient Equipment Pilot Programme
for Government Buildings


1. The Government spends a large and increasing sum of money on electricity consumption each year. In 1997-98, the electricity expenditure of all government departments amounted to over $1 billion. As part of the continuing global effort to reduce energy consumption and atmospheric pollution, the Government is committed to promoting the efficient use of resources and to improving Hong Kong's overall energy efficiency.

2. Following an Energy Audit Programme initiated by EMSD in 1993, EMSD has sought to achieve energy savings through a series of Energy Management Opportunities (EMOs) Implementation Programmes. EMOs are identified through energy audits and categorised into category 1, 2 or 3, depending on their complexity and the cost involved, with category 3 representing those that are relatively complex and require significant capital expenditure. The Phase 1 Pilot Scheme was introduced to tackle category 3 EMOs in 20 Government buildings over three financial years.

3. In 1995, the Secretary for the Treasury approved under delegated authority a non-recurrent commitment of $6 million for EMSD to carry out a 3-year Pilot Energy EMO Implementation Programme (the Phase I Programme). The objective of this Programme was to examine the cost effectiveness of various advanced energy-efficient building services technologies under local conditions.

4. The Phase 1 Programme targeted 20 major Government office buildings (listed at Annex A) which have regular working hours, typical floor layout and different types of lighting layouts. We installed new energy-efficient equipment, or replaced existing equipment, on one or two selected floors occupied by a single department/agency and maintained by EMSD. The energy-efficient equipment consisted of two main types: electronic lighting ballasts that minimise electricity consumption by fluorescent tubes; and variable speed drives (VSDs) that regulate levels of air-conditioning according to demand. A detailed description of this equipment is at Annex B. As retrofitting VSDs involves considerable disruption to the buildings or floors concerned, we planned the programme for installation of VSDs to coincide with scheduled maintenance programmes. The implementation programme is at Annex C.

5. The three-year Pilot Energy Management Opportunities (EMO) Implementation Programme will be completed in March 1999. There is a need to provide additional funding to enable the Programme to be extended to improve energy efficiency in Government buildings.


6. The Director of Electrical and Mechanical Services proposes to increase the approved commitment of the Pilot EMO Implementation Programme to carry out a Phase 2 Programme. We propose to seek Finance Committee's approval to increase the commitment from $6 million by $6 million to $12 million for the continuation of the Programme in Government Buildings


Phase 1 Pilot Programme

7. Analysis of the results of this Phase 1 Programme clearly shows that considerable savings can be achieved by using energy-efficient building services technologies. We estimate that the Phase 1 Programme will achieve savings 1 of about $1.7 million (or 6.8TJ in terms of energy) per year arising from lower energy consumption in the retrofitted Government buildings. The results also demonstrate that retrofitting this energy efficient equipment is cost-effective: we estimate a payback period of 4 years for electronic ballast equipment and 5.4 years for VSDs.

8. We are therefore working towards including electronic ballasts and VSDs as standard equipment in new Government buildings. We shall also be introducing programmes for installing electronic ballasts in existing Government buildings and for VSDs to be retrofitted as part of future reprovisioning/refurbishment programmes. In addition, we have shared our experience of the Phase 1 Pilot Programme with a number of private sector organisations in order to promote the wider use of energy-efficient technologies.

Phase 2 Pilot Programme

9. Following completion of the Phase 1 Programme, we propose to extend the pilot programme to assess the cost-effectiveness of a range of new products that have come onto the market as a result of recent developments in energy-efficient technology. The extended programme (the Phase 2 Programme) will target the five Government buildings listed at Annex D, selected on the basis of their design layouts, the non-standard office hours of the disciplinary services and availability of electricity meters to monitor energy consumption.

10. In the Phase 2 Programme, we propose to install three main types of energy-efficient equipment and building services systems that can readily be retrofitted to existing buildings, without causing major disruption to the users of the building, as follows:

  1. Lighting and Power

    1. Dimmable Lighting Ballast

      An energy controlling device that can dim the artificial light which will act as a supplement to the natural lighting to meet the lighting need to save energy.

    2. Combined Electronic Ballast & Emergency Module

      An energy controlling device that reduces the energy requirement for emergency lighting and EXIT signs of the building and provides emergency power supply during blackout.

    3. T5 Fluorescent Lamp

      A new type of fluorescent lamp that is slimmer in size, shorter in length and produces lighting output at a reduced energy input.

    4. Intelligent Lighting Control System

      A system that can work independently from the complicated building management system to offer energy saving through presence detection, lighting output modulation and manual remote dimming controller.

  2. Air-conditioning

    1. Presence Detector For Air-Conditioning Control

      A device that can sense the room being vacant and regulate the air conditioning to save energy.

    2. Indirect Evaporative Heat Recovery System

      A system that makes use of the cooled exhaust air to cool down the fresh air before it enters the building.

  3. Lifts and escalators

    1. Energy Optimiser in Motor and Drive System

      An energy control device to modulate the energy input to meet the loading requirement without reducing the speed of the motor.

A description of the equipment is at Annex E.

11. We aim to achieve an average annual savings of about $1.2 million per year 2 upon completion of the Phase 2 Programme. As the equipment/systems to be installed are relatively expensive, the payback period will be longer than for the Phase 1 Programme. However, we expect the cost of this equipment eventually to be reduced through market competition as demand for it increases, resulting in a payback period of three years or less for a large-scale retrofit project. If this is the case, we expect that there will be growing interest in incorporating such equipment in privately owned buildings. This will enlarge both the economic and environmental gains to the community.


12. The estimated cost of the Phase 2 Pilot EMO Implementation Programme is $6 million, made up as follows -

Cost $ million
Cost $ million
Total Cost
$ million
Lighting & Power0.80.7 1.5
Air Conditioning1.71.3 3.0
Lifts & Escalator0.80.7 1.5
3.32.7 6.0

The apportioning of the cost is based on the proportion of the electricity consumption of these category of installations in a typical office building. They are further sub-divided into equipment cost and labour cost based on the actual tender price in the Phase 1 Programme.


13. If the Finance Committee approves the proposal, we shall start the Phase 2 programme in July 1999 and completed by March 2001.

Planning, Environment and Lands Bureau
March 1999

Annex A

List of Government Buildings for Phase I
Pilot EMO Implementation Programme


  1. The buildings in Phase 1 Programme were selected due to their regular working hours, typical floor layout and adequate coverage of various technical design.

  2. Work was not carried out in building with @ due to its renovation programme.

  3. Work was not carried out in building with * due to the difficulties of making arrangement during the handover of sovereignty.

  4. Work was not carried out in buildings with # due to their demolishment programme.

Annex B

Brief Description of Energy Saving Equipment used

  1. Electronic Ballasts for Lighting Installations

    Conventional ballasts used for limiting and stabilising currents of fluorescent lamps are basically electromagnetic types, which consume a substantial amount of energy while in operation with the tube. Typical loss in each conventional ballast is about 10W. Modern technology in electronic ballasts operating at high frequency (HF), 25kHz to 45kHz, can eliminate most of the energy loss in conventional ballasts. Typical saving in lighting energy for direct replacement of conventional ballasts with HF electronic ballasts is more than 25%. Fluorescent lamp operating at HF can produce 10% more lumen output. Therefore, with the same amount of lumen output, lower lamp power is required with electronic ballast. Lamp life can also be increased up to 50% with lower lamp current.

  2. Variable Speed Drives (VSD) for Air Conditioning (AC) Installations

    Most variable flow systems (e.g. secondary chilled water circuits and variable air volume (VAV) systems) for AC in buildings used to employ by-pass valves, outlet dampers, inlet guide vanes, etc. to control their volume flow rates. There is no reduction in speed of the fan or pump. Pre-treated fresh air is also introduced into buildings at a constant rate via Fresh Air Units (FAUs), no matter how many occupants are present inside the buildings. The net result is that a lot of energy is wasted in motors, dampers and cooling fresh air unnecessarily. Variable speed drive system operating on modern electronic pulse-width modulation (PWM) technology can be used to adjust continuously the speed of the Air Handling Unit (AHU) fan motors and pump motors to match the exact loads required and save energy when the full capacity is not required.

Annex C

Pilot EMO Implementation Programme and

Amounts of Annual Energy Savings to date


Scope of Work

Cost HK$

Project Period

Description of Work

Annual Energy Saving

Dollar Value of Saving @ $0.9/kWh

Estimated Saving in 8 Estimated Saving in 8 yea


Queensway G.O.







Aug 96 – Mar 97

Aug 96 – Mar 97

Jun 97 – Jan 98

Retrofit of 200 electronic ballasts for essential lighting

Addition of 4 VSDs for FAUs

Addition of 3 VSDs for chilled water pumps

13,860 kWh

88,830 kWh

88,800 kWh








Eastern Law Court & G.O. Building



Oct 96 – Apr 97

Retrofit of 380 electronic ballasts for corridor and staircase lighting

32,714 kWh




Harbour Building





Aug 97 – Mar 98

Aug 97 – Mar 98

Retrofit of 960 electronic ballasts & luminaries for office and staircase lighting

Retrofit of VSDs for 2 VAV AHUs & 3 FAUs c/w CO2 sensors & energy efficiency motors








Southorn Centre





Sep 97 – Mar 98

Aug 97 – Mar 98

Retrofit of 930 electronic ballasts for office & staircase lighting

Retrofit of VSDs for 3 FAUs c/w CO2 sensors








Mong Kok KCRC G.O.





Sep 97 – Mar 98

Aug 97 – Mar 98

Retrofit of 350 electronic ballasts for office & staircase lighting

Retrofit of VSDs for 2 FAUs c/w CO2 sensors and 3 VAVs








Kowloon East G.O.



Sep 97 – Mar 98

Retrofit of 560 electronic ballasts for office & staircase lighting





Tsuen Wan G.O._





Sep 98 – Mar 99

Sep 98 – Mar 99

Retrofit of 350 electronic ballasts for office & staircase lighting

Retrofit of 6 nos. energy efficiency motor


Tuen Mun G.O.



Sep 98 – Mar 99

Retrofit of 3 nos. VSDs for VAV


Civil Eng. Building




Sep 98 – Mar 99

Retrofit of 700 electronic ballasts for office lighting


Sai Kung G.O.



Sep 98 – Mar 99

Retrofit of 996 electronic ballasts for office lighting


Yuen Long G.O.



Sep 98 – Mar 99

Retrofit of 720 electronic ballasts for office lighting


Tai Po G.O.



Sep 98 – Mar 99

Retrofit of 670 electronic ballasts for office lighting


Imm. Tower



Sep 98 – Mar 99

Retrofit of 550 electronic ballasts for office lighting


Revenue Tower





Sep 98 – Mar 99

Sep 98 – Mar 99

Retrofit of 1260 electronic ballasts for office lighting

Retrofit of 4 nos. VSDs for VAV


  1. The energy saving was calculated based on an average operating hours of 3,000 per year, except the emergency lighting which operates continuously throughout the year.

  2. No recurrent costs will be required in running the projects.

  3. The anticipated future energy savings will be the same for these installations.

  4. The estimated saving in 8 years has not taken the interest rate and the variation of electricity tariff into consideration.

Annex D

Tentative List of Government Buildings for Phase 2
Pilot EMO Implementation Programme

  1. Queensway G.O.*

  2. Southorn Centre

  3. North Point G.O.*

  4. Arsenal House*

  5. Central Fire Station

Notes :

  1. The list is tentative only. The list will be subject to change to suit site constraints and technical development in energy efficient equipment.

  2. Items with "*" are targeted for 1st year implementation.

Annex E

Brief Description of Energy Equipment used in Phase 2

  1. Lighting and Power

    1. Dimmable Lighting Ballasts

      Conventional lighting installations in commercial buildings are mostly lit at constant illumination level and equipped with simple On-Off switching only. The new electronic ballasts complete with digital dimmable control and light sensors can be used to adjust illumination level on a working plane in according to individual requirement or the amount of availability of daylight.
    2. Combined Electronic Ballasts & Emergency Modules

      Conventional emergency lighting and 'EXIT' sign in buildings are normally operated continuously with conventional ballasts back up by emergency modules and rechargeable batteries during power failure. The combined electronic ballast and emergency module specially designed for emergency lighting operation will reduce energy consumption by 30% and running at much lower temperature for longer battery life.

    3. T5 Fluorescent Lamp

      A new range of T5 lamps with a diameter of 16mm (5/8") is now available in Hong Kong. T5 lamps were extensively used in table lamps in the past. The new lamps are now extended to the range of application currently using T8 lamps. Standard wattage of lamps is 14W, 21W, 28W and 35W. They are 50mm shorter than the equivalent standard types and are operated on high frequency electronic ballasts. A T5 lamp is closer to a line source and is more energy efficient when use together with parabolic reflector in fluorescent luminaries.

    4. Intelligent Lighting Control System

      The new intelligent lighting control system utilises electronic digital control gear such as dimmable electronic ballasts, light sensors, presence detection, infra-red remote control etc. for more flexible lighting control. The system saves energy by utilising available daylight, detecting occupancy of space and manual dimming according to operational needs.

  2. Air-conditioning

    1. Presence Detector for Air Conditioning Control

      Conventional air conditioning system do not normally equip with present or occupancy sensors for resetting temperature or air volume flow to the minimum requirement of the air conditioned space. Incorporating present detectors in the AC control system could reduce the energy wastage during the unoccupied period.

    2. Indirect Evaporative Heat Recovery System

      The exhaust air in an air conditioning building is normally dumped outdoors without any energy recovery treatment. The indirect evaporative heat recovery system, which utilises the residual heat energy from water condensation and exhaust air at lower room temperature to pre-cool outdoor fresh air, normally at much higher temperature, before entering into the building for filtering and cooling.

  3. Lifts and escalators

    1. Energy Optimiser in Motor and Drive System

      Conventional motors used in buildings are normally designed to meet the maximum load condition even though their loads are subject to variation according to demand. Motor efficiency is much lower at light load condition. Modern motor control systems including soft starters and energy optimisers, which improve motor efficiency during part load condition. The new motor drive systems will regulate supply voltages to motor to suit the exact loading on motors and are applicable to escalator motors, water pumps, conveyor motors, etc.

1.The total electricity savings were estimated based on the measured saving from the first two years of the Phase I programme plus the projected savings for 1998/99.

2. Although the equipment costs are not available for estimation purpose, past experience indicates that average payback period of 5 years can generally be achieved by this energy saving equipment. With the investment of $6 million and a payback of 5 years, we estimate average annual savings in the order of $1.2 million per year.