It's something we all do dozens of times a day without thinking, yet opening and closing doors can generate electricity - and four Hong Kong students have invented a device to capture this energy.
Electdoor - the creation of Ho Wai-tat, 18, of Chan Sui Ki (La Salle) College, and his team members - stores the energy and converts it to power electrical devices, such as doorbells.
'The idea is to create a new form of renewable energy, while reducing the amount of resources wasted,' Wai-tat said yesterday.
The teenager and his colleagues - Lau Sui-lun, 19, Yiu Kwun-chuen, 17, and Man Chun-wai, 17 - have won a prize for their creation at the Joint School Science Exhibition.
The exhibits are on display at the Central Library in Causeway Bay until Thursday.
'One may argue that the energy produced by our device might be insignificant, but the fact is, the energy produced is considerable as we open and close doors many times a day,' Wai-tat said.
Sui-lun added: 'We can gather the energy produced each time and it becomes a big sum.' The team cited research showing the mainland consumed up to 8 billion batteries a year and discarded so many, it was causing serious pollution.
