The Hongkong Electric Co., Ltd. (HK Electric) is one of the two power utilities in Hong Kong and has been generating and delivering electricity to Hong Kong Island and Lamma Island of the Hong Kong Special Administrative Region for over 100 years. Number of employees in HK Electric as of end 2006 is around 1,900.
Being an environmentally responsible corporate citizen, HK Electric has long been committed to protecting and preserving Hong Kong’s environment and in support of sustainable development, while providing the city, which is an international financial and commercial centre, with a reliable world-class supply of electricity.
Case Background/Context
Hong Kong is characterized by a dense population and highly congested high-rise buildings. Supplying electricity by conventional oil-insulated electricity supply equipment, which is still being adopted by many other supply utilities, poses potential fire hazard not just to the residents but also to the general public. The waste oil treatment for these equipment and subsequent disposal of the waste oil also create environmental concerns. Moreover, gas suppression fire protection system has to be provided in electricity substations installed with oil-insulated equipment in line with Fire Services Department’s requirements. BTM, which is ozone-depleting, or CO2 were used in the majority of these gas suppression fire protection systems installed in the 70’s to 90’s. The installation and maintenance of the ozone-depleting BTM or CO2 fire protection systems have adverse impact on the environment and financial burdens to the premises owners. In view of the above, HK Electric started replacing its oil-insulated transmission and distribution equipment by highly reliable oil-less ones since the mid-70’s
The Main Objective of the Case
To eliminate environmental impacts and fire hazards to the general public and its customers, HK Electric has been replacing its oil-insulated transmission and distribution equipment by the highly reliable oil-less (vacuum, air and gas insulated) ones since the mid-70’s as a long-term project with an aim of extensive adoption of oil-less equipment in its 3,600 plus electricity distribution substations.
Problems and Difficulties
The scope of the project in terms of the number of substations and equipment involved is huge, and requires systematic planning, persistent implementation and skillful engineering coordination.
Nowadays HK Electric is an industry leader in electricity supply network with 100% high voltage switchgear and over 94% distribution transformers oil-free. Innovative measures are also adopted to help eliminate the environmental impacts associated with handling/treatment of aged/waste insulation oil and BTM/CO2 fire protection systems.
Outcomes
The highly reliable equipment and network enables HK Electric to provide world-class supply reliability of over 99.999% since 1997. Associated services to our customers are rendered with much reduced fire risk as well as equipment operational and maintenance cost on top of enhanced environmental performance.
The results of this initiative are summarized as follows:
- Reduced use of 73 tonnes of ozone-depleting BTM or 293 tonnes of CO2 in fire protection systems in electricity substations and the reduced annual release of 2.2 tonnes of BTM or 11.7 tonnes of CO2 to atmosphere during periodic maintenance by using oil-less electricity supply equipment, as compared to conventional oil-insulated equipment;
- Reduced generation of aged/waste insulation oil and savings in resource utilisation for periodic treatment/handling of 133 tonnes of aged/waste insulation oil annually by using oil-less electricity supply equipment, as compared to conventional oil-insulated equipment;
- Elimination of fire risks and significant savings in insurance premium.
Lessons Learned
The achievements are attributable to the clear vision and strong support of HK Electric’s Management for implementing various environmental initiatives as well as the systematic engineering planning and implementation by HK Electric employees and contractors.
We opine that adopting highly reliable oil-free electricity supplying equipment in place of conventional oil-insulated equipment can be used extensively in other electricity supply networks, especially in densely populated cities where electricity substations are erected in high-rise buildings. This would help enhance environmental protection and ensure safety for the general public.