Power outages across Southeast Asia expose vulnerabilities-
Grid failures in some of the leading economies of Southeast Asia in May were estimated to have impacted over 60 million people and resulted in known losses of more than $300 million. Although power was restored within eight to ten hours, these blackouts caused widespread panic and disruptions of essential services, while raising social and political concerns.
The key reasons behind these outages were largely identified as localised issues such as bush fires, lightning strikes, power plant shutdowns, technical snags in the transmission network, as well as the failure of safety mechanisms to automatically shut off load as frequencies dropped to dangerous levels. While power outages of a few hours occur routinely in several countries in the region, the scale of these blackouts was unprecedented. Among other things, this incident has exposed the vulnerability of the electricity grids in the region to supply disruptions and the critical need to upgrade the currently weak and ageing power infrastructure.
Furthermore, these episodes also underscore the need for greater investments in infrastructure, as well as harmonised regulatory measures across borders, to isolate areas of failures and localise their impact, should such events recur. Such action is particularly critical as the region moves towards an integrated electric power grid by 2020.
Southeast Asia Infrastructure examines the sequence of events that led to the blackouts in the region and the gaps in the power infrastructure that need to be addressed…
An unfortunate chain of events
The first major blackout incident in May was reported in the Philippines: the country experienced a major power failure in the Luzon region including the capital, Manila, and the surrounding provinces on May 8, 2013 (from 1.51 p.m. to 11.50 p.m.). According to the National Grid Corporation of the Philippines (NGCP), the country’s transmission network operator, the blackout started with the tripping of its 230 kV Binan–Calaca transmission line between the province of Laguna and Quezon and Unit 2 of the Calaca power plant located in the province of Batangas (600 MW capacity; operated by the DMCI Power Corporation).
This event triggered a system disturbance that caused several power plants to shut down. The affected plants included the Santa Rita and San Lorenzo natural gas plants in Batangas; two coal plants at Sual in Pangasinan; and a power plant in Quezon. These plants contribute about 3,700 MW to the grid, equivalent to around half of the supply needs of the Manila Electric Company (Meralco), and about 45 per cent of the entire Luzon grid requirements (up to 8,300 MW). The franchise area of Meralco, the biggest power retailer and distributor in the country, covers more than 5 million households in Metro Manila and outlying provinces.
According to the preliminary report on the power outage submitted by the NGCP to the Department of Energy, a bush fire was responsible for the line tripping. Power was finally restored in all provinces at 11.50 p.m. Following the incident, the Department of Energy asked the Grid Management Committee to conduct its own investigation, in accordance with the Grid Code. The NGCP has announced plans to invest nearly PhP 200 million ($4.6 million, PhP 1=$0.023) in the replacement of its old wood poles that are used to transmit power (at 69 kV) with more durable steel poles that can withstand such disturbances.
The second major blackout incident in the region occurred in Thailand on May 21, which impacted 14 provinces in the southern part of the country. According to the Electricity Generating Authority of Thailand (EGAT), the outage that occurred at around 7 p.m. was caused by the malfunctioning of the main power transmission lines from the central to the southern region (from Ratchaburi to Bang Saphan district in Prachuap Khiri Khan).
At 8 a.m. on May 21, one of the two 500 kV lines that transmits power from the central to the southern region was discharged from the system for maintenance. At 5.26 p.m., lightning strikes resulted in the malfunctioning of the other 500 kV line connecting the two regions. As a consequence, authorities were forced to increase power transmission through the 230 kV lines, which caused them to malfunction later due to the overload. Electricity from the four main power plants in the southern region provinces – Nakhon Si Thammarat, Songkhla, Krabi, and Surat Thani – was discharged from the system automatically for safety reasons, after the power fell below the standard 50 Hz grid frequency. Repair works carried out by EGAT helped to restore power by 11.45 p.m.
The third major blackout incident was reported in Vietnam the next day. All 22 cities and provinces in the southern region of Vietnam suffered a blackout on May 22 due to an incident that affected a high voltage power line. The incident occurred at 2 p.m. local time when a tall tree being transported by a crane in the southern province of Binh Duong inadvertently collided with the 500 kV Di Linh–Tan Dinh line nearby, which created a domino effect, as all linked power transmission lines were affected.
The majority of the electricity supplied to the southern region comes from the north through the 500 kV line, with the remainder coming from some thermal power plants in the central and southern localities, as well as hydropower plants in the central region. In an official response to the incident, Deputy Minister of Industry and Trade Le Duong Quang stated, “Looking at the last incident, the first thing we can see is the vulnerability of the 500 kV transmission line. Similar incidents occur not only in our country, but also in some more developed countries.” By 10.40 p.m., electricity was restored in all provinces. The incident also affected Cambodia, as it buys electricity from Vietnam.
Gaps in infrastructure
Besides the lack of adequate generation capacity, the grid blackouts have turned the spotlight on the region’s poor grid infrastructure, as well as technical and maintenance issues. As R. Krishnaswamy, Vice-President of Energy and Environment at Frost & Sullivan, Asia Pacific, commented, “In countries like Thailand, the margin reserves are quite reasonable to protect systems from outages; however, in Vietnam, the Philippines, and Cambodia, there are problems both on the power availability as well as the grid fronts.”
For instance, in Vietnam, official estimates show that over 60 per cent of the disturbances in the transmission network can be attributed to the failure of protection systems. Further, the 500 kV north–south line, the major power transmission line of Vietnam that was put into operation in 1994, is heavily overloaded; in fact, it has been facing technical difficulties.
In the Philippines, old and defective equipment and assets have posed a major challenge for the country’s transmission systems. A review of the existing conditions of the transmission lines and related assets has shown that the majority are nearing the end of their economic life. As per the NGCP’s 2012 edition of the Transmission Development Plan, almost 56 per cent of protection relays, 27 per cent of current transformers, and 39 per cent of power transformers have completed nearly four-fifths of their economic life and hence would need replacement. Moreover, of the 19,822.25 ckt. km of transmission lines under the NGCP, around 2,793.41 ckt. km, or 14 per cent, are 30 years or older, while around 747.22 ckt. km, or 4 per cent, are 50 years or older.
In Cambodia, investments in high voltage transmission systems have been inadequate, owing to funding constraints. As of 2012, the country had only four high voltage lines – three at 115 kV (414.95 km) and one at 230 kV (91 km). Further, due to technical constraints in its interconnections with neighbouring Thailand and Vietnam, the quantity of power that can be imported from these countries is limited. Hence, the country routinely experiences outages for a few hours every day.
These issues would need to be addressed not only to improve power reliability in their respective countries, but also to facilitate the development of regional interconnection projects. Sector experts point out that such outages can exert an adverse impact on the ASEAN Power Grid project as well. The project that aims to facilitate cross-border power interconnections and trade would be jeopardised, as countries such as Singapore, Indonesia, and Malaysia, which have more established grid networks, would not want to be exposed to the vulnerabilities of the power supply systems in other economies in the event of such blackouts.
Technological solutions to improve service quality
As such, the core issue faced by the transmission sector in these countries is the lack of technology, as explained by Maurice Dres, Regional Vice-President, East Asia & Pacific, Alstom Grid: “Development of interconnection technologies, like high voltage direct current transmission, reduces the impact of minor faults on national grids and increases reliability across the region. At the same time, the region would need to work to improve availability and quality of service to maintain this reliability and extend the lifetime of assets. The region has the ability to leapfrog by adopting modern, proven technologies already in place in more developed nations.”
Thus far, network operators and utilities have drawn up significant investment plans for grid modernisation and system strengthening projects. Of the proposed PhP 48 billion ($1.1 billion) to be invested between 2011 and 2015, the NGCP in the Philippines has earmarked an investment of nearly PhP 12 billion ($276 million) for 2013 to enhance the country’s transmission networks.
Meanwhile, the Vietnam Electricity Group (EVN), the country’s main transmission network operator, plans to spend about 90 trillion dong ($4 billion, 1 dong=$0.00004) to upgrade its power transmission network between 2013 and 2015. To address concerns over grid safety, it plans to increase the number of connectors to the 500 kV line and power sources. EVN is also looking to set up another 500 kV line from the north to the south to bolster the safety of the national grid in the near future.
Thailand that already has an extensive transmission network (31,556 ckt. km of transmission lines and 212 substations with the capacity to carry 86,730 MVA of power) is now focusing on automating its network through advanced technologies. Supervisory control and data acquisition systems, protection systems, wide area management systems, and automatic fault analysis are some of the key technologies that are being deployed by EGAT as part of its smart grid technology road map.
Global lessons
While these investments are a step in the right direction in reducing the risk of outages in the future, the region could also draw lessons from global experiences in grid blackout. A recent research by the Massachusetts Institute of Technology (MIT) on global grid blackouts concludes that cascading blackouts occur when seemingly small “most vulnerable pairs of failures” occur together among the millions of possible pairs of failures. This was also the case in the world’s largest ever grid outage when an initial tripped line and relay problem resulted in the world’s largest ever grid outage in India in 2012 which affected 600 million people. MIT researchers have now designed an algorithm that “prunes” all the possible combinations down to the pairs most likely to cause widespread damage.
The MIT “computer program” will be a boon for system designers who have so far relied on islanding systems in their design where in the event of blackouts these microgrids would use local generation to allow them to disconnect from the grid.
As power grids in Southeast Asia become more complex and market oriented along with exposure to weather uncertainties, steps to enhance the resilience of power grids through a combination of improved technology and regulatory measures to prevent recurrence of cascading failures experienced recently in the region would be imperative.
