The world's largest stand alone integrated photovoltaic (BIPV) project started transmitting power to the grid in Shanghai on Sunday in another move showcasing China's commitment to reduced carbon emissions.

The 6.68-megawatt solar system can produce 6.3 million kilowatt-hours (kwh) of electricity per year to meet the needs of 12,000 Shanghai households. It will cut coal consumption by 2,254 tons, while reducing carbon emissions by 6,600 tons.

The project has been installed on the awnings on both sides of the newly completed Hongqiao Station of the Beijing-Shanghai High-Speed Railway. Its 20,000 solar panels cover a roof area of 61,000 sq m and have produced 300,000 kwh power since the 160 million-yuan project began operation two weeks ago.

"The project is another manifestation of China's commitment to reducing carbon emissions to fight climate change. It comes after the country set a voluntary target of cutting carbon intensity per unit of GDP by 40 to 45 percent by 2020," said Yu Hailong, general manager of the Beijing-based China Energy Conservation and Environmental Protection Group (CECEP), the project's developer.

"As a pilot project, it will help stimulate the development of solar energy in China and promote the construction of more environmentally friendly railway stations," he said.

Chief engineer of the Ministry of Railway Zheng Jian said China will further encourage BIPV implementation at railway stations, which serve as an ideal vehicle to promote the technology.

A 2.2-MV BIPV system has also been installed at the Wuhan Station of the Wuhan-Guangzhou High-speed Railway. The system was connected to the national grid in May, CECEP deputy manager Chen Shuguang said.

"BIPV technology does not take up extra space, because it is integrated into buildings' design and construction. It is especially suitable for China's eastern areas, where there are limited land resources yet greater energy demand," Chen said.

The development of renewable energy has been topping the central government's agenda. It aims to have an installed capacity of 20 gigawatts of solar units and 100 gigawatts of wind power by 2020, official statistics show.

A number of world-class pilot projects have been completed this year in Shanghai, which is hosting the World Expo 2010.

They include the 4.6-MV solar energy generation system installed in the Expo Garden and China's first offshore wind farm, the 102-MV Donghai Bridge wind power project, which started transmitting electricity to the national grid in early July.

The government is also tendering for bids to develop 13 solar power projects with a combined capacity of 280 megawatts in the western regions, following last year's bidding for a 10-megawatt solar power plant in Gansu province's Dunhuang.

But Song Aizhen, of the solar energy branch of CECEP, said the government needs to come up with more detailed subsidy plans for renewable energies to encourage more active corporate investment.

"Take solar energy for instance - its cost is already three times that of thermal power, and BIPV technologies are even more expensive," she said.

"So government subsidies will be crucial to the technology's wider application."