By Shen Lin, Xu Yuyao, People's Daily
On the top of snow-covered mountains with an altitude of over 5,000 meters in the suburbs of Gar county, Ngari prefecture, southwest China's Tibet autonomous region, stand a number of gigantic transmission towers, which are there to ensure stable power supply for families at the foot of the mountains and beyond.
With a total length of more than 1600 kilometers, the power transmission line, also known as the Ngari-central Tibet Power Grid Interconnection Project, spans 10 counties and districts in two prefecture-level cities of Tibet and was put into operation at the end of 2020. It is a 500 kV power transmission and transformation project with the highest altitude and longest distance in the world.
The project marks the end of an era in which Ngari's power supply relied on an isolated grid of its own and has fundamentally solved power shortage in the prefecture, offering safe and reliable electricity for 380,000 farmers and herdsmen in 16 counties along its route.
For more than two years, the project provides stable electricity supply, meets the needs of residents in lighting and heating, as well as needs for industrial development.
79-year-old Chagoin is a resident of a nursing home of Ngari. Her health is getting worse with age, thus an oxygenerator is needed constantly to ease her condition.
"There are many other seniors like Chagoin in the nursing home. The oxygenerators donated by the government could help improving their health conditions," said Awang, head of the nursing home.
"We know that oxygen care for the elderly is important, but the power supply was unstable in the past, high-power appliances would always blow the fuse, let alone wide application of oxygenerators," Awang told People's Daily.
In the second year after the project was put into use, the nursing home introduced a series of equipment to better care for seniors living there.
According to Awang, oxygenerators as well as all other types of appliances can now be safely used in the nursing home without worring about tripping.
Since the prefecture's connection to the state power grid, both nursing homes and residential complexes have upgraded their power equipment, said Losang Phuntsog, an employee of the Ngari branch of the State Grid Corporation of China.
Before the connection, power shortage was common in winter in the prefecture. Today, radiant floor heating systems and electric radiators are widely used by the local people, which is safer and cleaner.
Now, diesel and petrol generators are used less and less in business. Wang Baolong, who works for Tibet Ali Hotel, told People's Daily that generators consume much fuel and thus leads to a high cost that's much more expensive than the electricity from the grid.
"With stable power supply, we don't have to spend that much anymore," he said.
Since the project was put into use, the maximum electrical load in Ngari has expanded by 12.63 percent, with a supply reliability rate of 99.68 percent. The project has transmitted 218 million kWh of electricity in the past two years, or 76.49 percent of the total power supply in Ngari prefecture.
"Besides, the project has lowered electricity price by over 55 percent. It has also improved investment and business environment, injecting new impetus into Ngari's economic and social development," said the person in charge of the Ngari branch of State Grid Corporation of China.
Though the project is a huge benefit for Ngari, the maintanance of the project in such a sparsely populated prefecture is no doubt a challenge.
The ardurous inspection tours along cliffs are extremely difficult. However, workers of the maintenance group of the project have long been used to the undertaking.
Jamyang Kelsang, head of the maintenance group told People's Daily that once a sudden failure took place along the main line and special spare parts were needed to completely fix it. However, the parts couldn't be found locally, he and other maintenance staff members had to stay in the place where the failure was for around a week to maintain emergency operation until the spare parts were delivered.
"Stable power supply is not only about the construction of the project, but also the maintenance of it," Jamyang Kelsang said, adding that the project means greater convenience for residents and merchants, but to maintenance staff members, it means greater responsibility.