A kite string falling on a power transmission line on April 26 caused a massive short circuit, severing electricity supply to 21 districts, a recent probe found, highlighting the risks for the national power grid arising out of its close proximity to human settlements.
The grid failure sent five major newly-built power plants to shut down, leading to hours of outage in some areas in south-western, southern and central Bangladesh, creating a situation that could have potentially damaged expensive power machines.聽聽
鈥榃e have come to the conclusion on what caused the transient fault leading to the grid failure after consulting locals and evaluating some evidence,鈥� said Syed Abadullah Haider Ali, who headed the probe into the grid failure.
The Power Grid Company of Bangladesh launched the probe on April 27 along with another probe launched by the Power Division.
The Power Division probe has yet to complete.
The kite string fell on the 400kv power transmission line connecting two important power substations in Gopalganj district and Aminbazar on the outskirts of Dhaka city, triggering the short circuit, Haider said. The substations, crucial to electricity supply in Dhaka, evacuate about 1,000MW from several power plants.
Globally, said Saeed Mahmud Ullah, who teaches electrical and electronic engineering at Dhaka University, high voltage power lines, such as, the 400kv one, are usually insulated to avoid extra weight and expense.
The standard height of power supply lines varied, he said, adding that the minimum height of low-voltage power lines, such as 33kv lines, should be at least 20 feet. The 400kv line should hang at least 50 feet above ground, he said.
鈥楥reating public awareness about the importance of staying away from power lines is the key to avoiding this type of accident,鈥� said Mahmud.
鈥楾he problem is rather simple but its consequences are great,鈥� he said.聽
Officials at the PGCB said that power transmission lines usually passed at least 45 feet overhead.
Kite flying is a popular outdoor sport in the country, particularly in rural areas in autumn. Kite fliers often use a thread coated with powdered glass or other abrasives that may increase the thread鈥檚 electrical conductivity, experts have said.聽
But kite flying is not the only threat. Thunderstorms, which occur in pre-monsoon months between March and May, often interrupt power supply by flying snapped tree branches on the power lines.
In some areas high voltage power lines are drawn dangerously over villages in the densely-populated Bangladesh. In one incident in the past, a villager had complained to the Consumers Association of Bangladesh about a high voltage power line passing over his home.
People coming in contact with the power supply system and getting killed are common in Bangladesh, which achieved universal electrification through a rapid expansion of the power sector with hardly any robust public campaigns for safety awareness.聽聽聽
In Dhaka city, high voltage and naked power lines are seen hanging close to buildings risking lives. Some of the lines hang dangerously low in some areas. Fire incidents triggered by snapped high voltage lines, such as 1,100kv lines, were reported in Dhaka in the past.
Data is scarce on casualties from different kinds of accidents involving contacts with live power cables in the country.聽
In 2011, the Centre for Injury Prevention and Research revealed in a study that electrical injuries caused about a third of annual burn injuries. According to the study, an estimated 5,600 people die from burn and electrical injuries every year in the country, particularly in rural areas.
Children are most exposed to electrical injury risks, the report further says.
The latest national grid failure was the second such incident happened in 46 days. On March 11, a fire in the Aminbazar substation triggered the first grid failure this year.
Bangladesh鈥檚 current installed power generation capacity is over 27,645MW. On April 30 last year, the country achieved its highest-ever power supply of over 16,477MW.
