Part of the extra high voltage 500kV transmission line that runs through the south central province of Quang Nam.(Photo: VNA) Hanoi (VNS/VNA) - May 27 this year will mark 25 years since Vietnam’s first 500kV powertransmission line was switched on, connecting the north and south of thecountry with an uninterrupted electricity supply.
Dubbed the ‘backbone’ of the national power grid, the power line is one of Vietnam’smost significant technological feats, given how construction workers andtechnicians raced against time and finished nearly 1,500km of cables through 14provinces and cities in a mere two years.
In the early 1990s, the southern region suffered from a serious electricitydeficiency – on average, a day of uninterrupted power would be followed by atwo or three-day long outage, at a time where the country had started to pushfor a free-market economic policy following the adoption of 'Doi moi' (renewal)in 1986.
The situation was not only unimaginable by today’s standards but also achallenging puzzle for the country’s authorities as the southern region’sresources was not being put to use with such an unstable power supply.
At the same time, the northern region was recording an excess of electricity: anumber of large-scale hydropower projects including Hoa Binh and thermopowerplants in Uong Bi or Pha Lai were not even running at full capacity due to lowdemand.
The then Ministry of Energy, tasked with coming up with a solution to thisconundrum, proposed a plan to transport electricity produced in the north tothe south via an extra-high voltage 500kV power line that could bring 2 billionkWh a year to HCM City, the southern economic centre.
Despite skepticism from both inside and outside the country over thefeasibility, efficiency and ambitious construction time of the project, then Prime Minister Vo Van Kiet signed off on the project in February 1992 andthe 544 million USD project commenced in early April the same year.
During the 700 days of construction, some locations looked to be so remote itwould be impossible to transport equipment and materials to implement theproject, including the Hai Van Pass and the highly dangerous Lo Xo Pass in KonTum province, but it was eventually done thanks to thousands of local peoplecarrying sacks of cement and steel up the mountains and hundreds of othersproviding logistics for the entire operation.
The hard work of dozens of thousands of workers and technicians finally paidoff in May 27, 1994, when the 500kV substation in Pleiku in the centralhighlands province of Gia Lai powered up the two grids in the north and south forthe first time in history.
To get the system up and running was already a major achievement, butmaintaining a system of this scale was a constant battle against the elementsand sometimes, people.
Before the second circuit of the 500kv power transmission system went intooperation in 2005, all of the power was carried by the first circuit for 10years, and it frequently ran at full capacity and overloading was not uncommon.
Ho Cong, deputy director of the Power Transmission Company No 3, which overseesthe power grid in nine central highlands and south-central provinces under theState-run Vietnam Electricity (EVN), said maintenance and operation of thepower line in this region was even harder, due to the complex combination ofterrain from treacherous jungle-covered mountains to deep rivers.
“And then there are downpours in the rainy season, which trigger flash floodsand landslides. In the dry season, the heat, the scorching sunlight andferocious dust storms are insufferable. We need to stay on high alert at timesas the risk of fire [from vegetation] near the power line is constant,” Congtold the Vietnam News Agency.
The power line also passes through several plantations of rubber, coffee andpepper, as well as as forests of pine and cajuputs, which have a habit offalling – especially during the monsoon – and risk disrupting the supply forthe entire southern region.
“Another challenge for us is that in the Central Highlands, with the power linerunning through areas mostly populated by ethnic minority groups of Ba Na, E De, Xe Dang, who practice slash-and-burn farming, so it took us a lot of timeto educate them on the need to do it safely with a controlled buffer zone toavoid the risk of fire to the power line,” Cong said.
Besides, in several locations, there are still outdated devices and equipmentthat need to be replaced or upgraded.
The power sector in central highland and south-central provinces alsofrequently need to upgrade the power system to accommodate hydropower plantssprouting up in the uplands in subsequent years.
He noted that in the quarter of the decade since the power transmission systemwas built, the technology landscape had changed significantly and there hademerged several solutions – including the new control system SupervisoryControl and Data Acquisition, thermographic cameras that could help remotelyraise alarms over possible risks, devices to help locate precisely the point ofdisruption on the length of the line – but the professional skills andknowledge of engineers and technicians still mattered.
If the first 500kV circuit could be considered an epic example of theVietnamese people’s strong will, then the second and third circuits and theefforts of all those involved in making sure electricity runs uninterrupted –all done by Vietnamese – could be seen as a multi-generational extension ofthat epic effort, Cong said.-VNS/VNA
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