Macau, 23 November 2022

Companhia de Electricidade de Macau - CEM, S.A. (CEM) has been playing a key role and at the forefront of ensuring electricity for the daily operation of society and the sustainable development of Macau. It continues to build and optimize the facilities for generation as well as transmission and distribution. CEM's power supply service has always been at the top level in the world, and the reliability of power supply based on CEM's responsibility has reached 99.9999% in the past two years. 

The third Guangdong-Macau 220kV interconnection (the 3^rd interconnection) jointly constructed by CEM and China Southern Power Grid (CSG) will be energized soon. After the energization, it will further improve the stability of electricity consumption in Macau and provide power guarantee for the diversified development of Macau's economy. Today, CEM invited a number of local media outlets to visit the Pac On Substation to learn about the construction process of the 220kV substation and the 3^rd interconnection.

The Pac On Substation

The Pac On Substation is the largest substation in Macau so far, and it is CEM’s first substation to adopt the one-and-half breaker connection mode, which significantly enhances the reliability of power supply and the flexibility of operation and dispatch. For every enclosed circuit, three breakers are connected to two busbars and two feeders, with each feeder provided with two breakers. One of the advantages of this connection design is that a faulted busbar can be quickly isolated or a faulted breaker can be suspended without causing any outgoing line outage. The Pac On Substation is installed with world-class state-of-the-art equipment, and 13 sets of high-voltage cables are laid under the congested road. With the support of the relevant departments of the Macau SAR Government, CEM and the construction parties fully cooperated, finally overcome various unfavorable factors and completed the iconic power facility in Macau.

Pac On Substation - Let the Numbers Speak for Themselves:

- The indoor low-voltage cables measure a total of around 71km, which is 16km longer than the 55km Hong Kong–Zhuhai–Macau Bridge;

- It took more than 6,000 hours to process about 5,000kg of insulating gas used in the construction of Pac On Substation;

- Over 3,100 cables were connected for on-site construction, 50% higher than that at the Lotus Substation of the 2^nd interconnection;

- About 600 wooden boxes of 220kV GIS components were stored in a merely 700 sqm space, with the biggest one being 4 meters tall and 4.85 meters long;

- A total of 131 220kV GIS switches and over 580 air chambers were installed at Pac On Substation, an increase of 50% and 200% respectively compared to the Lotus Substation. About 500 air chambers were installed on the site, subject to stringent environmental requirements and controls. 

- A total of 91 220kV protection and control panel cabinets, 103 protection devices were installed, with more than 6,000 monitoring signals. It took 150 days to complete the installation and acceptance check. 

- The Pac On Substation is connected to 13 groups of high-voltage cables, with five 220/110kV 180 MVA transformers and three 220kV 80 MVAR resistors. For 220kV, there are eight series circuits with 15 feeders; as for 110kV, there are six busbars connecting 24 feeders. It is by far the largest substation of CEM.

The 3^rd Interconnection

The 3^rd interconnection started construction in Zhuhai, Guangdong in 2018. Along with the related 220kV Pac On Substation, the 3^rd interconnection is a key project under the Framework Agreement on Cooperation Between Guangdong and Macau, and also an important infrastructure project in Guangdong-Hong Kong-Macau Greater Bay Area. The project is composed of the 220kV Pac On Substation in Macau, the 220kV Yandun Substation in Zhuhai, and the cable line of about 10.3km between the two substations, with a total investment of about MOP 1.4 billion.

The power supply network between Guangdong and Macau was first established in 1984 when CEM invested in the Shaoguan Power Station in Guangdong to transmit electricity to Macau through a 110kV transmission line. Since then, the volume of the network has been on the rise. Currently, the network is connected by 220kV sextuple-circuit main supply lines (220kV Zhuhai Line A, B and C and 220kV Hengqin-Lotus Line A, B and C) and four circuits of 110kV backup lines (110kV Gongbei-Macau Line A and B and 110kV CSPG-Macau Line A and B). Upon the commissioning of the 3^rd interconnection, CSG will be able to supply power via three interconnections in the northern, central and southern Macau and raise its power supply capacity to 1.7 million kW, meeting Macau’s projected peak demand for the 14^th Five-Year Plan period and Macau SAR Government’s “N-1” requirements on the reliability of power supply.

To align with the country’s goals of “carbon peak” and “carbon neutrality”, CEM has been dedicated to ensuring the good air quality around power stations and enhancing Macau's air quality monitoring network. To realize the corporate goal of becoming a leading energy service provider in Asia, CEM will continue adopting a localized power generation strategy, primarily using natural gas, a clean energy, in power generation, while seeking new collaboration opportunities in clean energy between Guangdong and Macau. CEM will also continue stepping up efforts in the construction of smart grids to achieve digital transformation, including replacing old meters with smart ones gradually, coordinating with the Macau SAR Government's plan to promote electric vehicles (EVs), and improving EV recharging network and infrastructure, in a bid to jointly develop Macau into a green and dynamic city with diverse exciting elements.