Storms expose structural problems behind failure of power networks

PUBLISHED : Saturday, 09 February, 2008, 12:00am
UPDATED : Saturday, 09 February, 2008, 12:00am

Underinvestment in power grids, a growing tendency to rely on long-distance electricity transmission from remote regions and a lack of contingency planning are structural problems exposed by the snowstorm-induced power cuts on the mainland, according to analysts.

As millions of people in central provinces mark the Lunar New Year in their power and water-deprived homes, it is time for officials at the nation's power and economic policies planning authorities to reflect on what could have been done to prevent or reduce economic losses from such disasters.

While snow and ice storms of the magnitude seen last month may happen only once in half a century, a stronger power distribution system and better contingency planning could have lessened the damage.

Analysts say vulnerability of the power grid system stemmed partly from underinvestment, as the system's expansion lagged behind generation capacity, which more than doubled in the past five years, at an average annual rate of 16 per cent.

'China's power grids are not well-connected and are exposed to structural risks as the grid companies were not catching up with the expansion of the power producers,' says Fitch Ratings director of energy and utilities Simon Wong.

According to a Lehman Brothers research report citing State Electricity Regulatory Commission figures, the central power grid had an average reliability rate of 99.82 per cent in 2006, with the average household suffering 16 hours of power cuts that year. The grid covers Chongqing city and Henan, Hubei, Hunan, Jiangxi and Sichuan provinces, most of which were hard hit by the winter storms.

The regional grid ranked first in terms of population but second-worst among the nation's six regional grids on reliability, after the sparsely populated northwest grid.

The statistics only add to the case for an overhaul of the grid.

While more power lines alone may not have been enough to prevent the power cuts caused by storms - the lines can still collapse under the weight of ice - investing in better connectivity between regional power grids could have at least reduced the damage.

Robert Blohm, a member of the North American Electric Reliability Council and an adviser to monopoly power distributor State Grid Corp of China, says the power industry lacks leadership in putting the improvement of reliability first since its focus was on expanding the quantity of power supply not quality.

'It is not that they are not interested in adopting software and planning tools to improve reliability and contingency planning, but there is no leadership to move ahead,' Mr Blohm said.

He cautioned against relying solely on rerouting electricity from one grid to another in case of emergency power failures, as this could disturb the entire system and cause cuts in other regions, similar to the intergrid power cuts in North America a few years ago.

Mr Blohm also said the mainland's growing reliance on transmission of electricity from large-scale generators in remote regions to the vast coastal markets via long-distance power lines had exposed it to greater risks of widespread breakdowns. He said central China could draw lessons from the massive blackouts of Canada's Quebec province in the late 1990s, when freezing rain pulled down power lines, caused power cuts and cut water supplies to millions as water filtration systems could not operate. Both central China and Quebec have large hydropower plants that rely on long-distance power transmission.

'Fortunately, Quebec has large gas-fired power plants that can be fired up at the last minute to allow water filtration plants to operate,' Mr Blohm said.

Despite the gloom in the aftermath of the snowstorms, the disaster could spur greater investment in the power distribution sector.

Already, Beijing has upgraded the nation's planned investment in power grids to 1.8 trillion yuan for the five years to 2010, from 1.2 trillion yuan planned in 2006, according to the Lehman report.