Some major cities in China are experiencing their worst power shortage problem since the 1980s. Indeed, the power shortage may be the greatest obstacle to sustaining the country's rapid economic growth for the next decade. China's gross domestic product could have grown even more last year had power blackouts not interrupted factory production. China's economy officially grew 9.1 per cent last year but it might have been as high as 10.4% according to the State Power Economic Research Centre. In the first six months of 2004, 24 out of the China's 31 provinces and municipalities have suffered from blackouts because power stations could not generate enough electricity for all of the country's factories. This summer, China's power companies are expected to fall short by 30 million kilowatts, more than half of which will be needed in Shanghai and the eastern provinces of Jiangsu and Zhejiang. These three areas in the Yangtze Delta region have been hit the hardest by power outages because their local economies are growing much faster than elsewhere. The authorities have tried to alleviate the power outages by raising electricity prices and sometimes banning the sale of electricity to the steel, aluminium, cement and chemical industries, which takes up almost 30% of China's total electricity consumption. A growing number of factories in the Yangtze Delta region are being affected for the first time this summer by additional government measures to stagger their power usage outside of peak hours. The root of today's power shortages can be traced back to the Asian financial crisis. At the end of crisis in 1999, China's economy grew at a relatively sluggish pace of 7.1 per cent, leaving the country with a surplus of power. At the time, government bureaucrats approved the construction of fewer power plants. Consequently, when demand for electricity surged in recent years, China did not have enough power plants to keep up. Now realising that they underestimated demand, Chinese power companies have been investing heavily to build new plants to increase power generation capacity by 130 gigawatts, or almost a third more than China's current capacity. But the new power plants won't begin operations until 2006 and 2007. More than 90 per will be noxious gas-emitting, coal-fired plants, cheaper to build than natural gas and other renewable energy power plants.