By Zong He
At the ‘Jiangsu Football City League’ on 31st August, Nantong team defeated Suzhou team 2:1 at home. What is worth mentioning is that the world’s third largest and China’s first open-roof stadium —— Nantong Sports & Exhibition Center slowly unfolded the 2,200-ton steel wings, which drew astonished exclamations from more than 30,000 spectators.
‘How much electricity does it take to move the roof? In response to many spectators’ questions, Nantong Power Supply Company released the actual measured data after the game: 443.23 kWh.
‘The opening and closing of the stadium roof is driven by 8 high-precision hydraulic winches. Any slight deviations during operation are corrected by the background system commanding some of the 44 trolleys on the roof. The power of each winch is 110 kilowatts and the power of each trolley is 2.2 kilowatts. The whole process of opening the roof equipment is about 25 minutes. Assuming that opening the roof once requires starting 1/4 of the trolleys for correction, it is also necessary to consider that the energy conversion efficiency of equipment such as hydraulic devices is about 85%.’ Yang Yi, a worker of the power supply company, used a formula to calculate the power consumption required to open the roof once - electric power multiplied by time, which equals 443.23 kWh. Calculated at 0.7 yuan per kilowatt-hour, it is about 310 yuan.