Blind expansion of the power sector to boost economic development may lead to another round of overheating and inflation, a senior mainland official has warned. Zhang Guobao, a vice-chairman of the State Development and Reform Commission, said even though there had been progress in addressing the acute power shortage, the mainland still faced unprecedented challenges in adjusting its energy structure. 'We must stay on alert for a stage of development that will require the [power industry] to grow at a pace ... exceeding its capability and an economic growth rate of 9.5 per cent while ignoring the actual conditions [such as transportation, material supplies and pollution],' he told an energy strategy forum in Beijing yesterday. Mr Zhang said the quest for sustainable development was not being helped by an over-reliance on increasing the nation's power-generating capacity and ignorance of structural problems. He admitted that the blind development of power projects and coal mines had resulted in serious environmental problems, such as air pollution and water shortages. Mr Zhang criticised local authorities for irresponsibly giving the green light to illegal small coal mines and power plants, which posed serious environmental and safety problems. His concerns over the nation's troubled mining industry were supported by Wang Xianzheng , a vice-director of the State Administration for Safe Production Supervision. Mr Wang said despite an overall improvement in statistics related to the country's 25,000 coal mines last year, serious accidents in Chengde and Fuxin this year showed much needed to be done to improve mine safety. Of the total 1.9 billion tonnes of coal produced nationwide last year, nearly 750 million tonnes came from illegal mines or those operating above their capacity, according to Mr Wang. Meanwhile, Shanxi - the mainland's leading coal producer - would suffer a power shortage of 3 million kilowatts this summer, Xinhua reported yesterday.