State Grid Corporation of China, the biggest power-network operator in the country by market share, said it will expand its smart grid construction in fileds such as electric-charging stations and wind-power installations in 2011.

The company said it will build 173 electric-charging points, a sevenfold increase on the existing number, with 9,211 charging poles in 26 provincial regions this year.

"This will improve the electric-auto industry because the increasing number of charging stations will clear up the biggest obstacle for the industry," said Yao Jianguo, director of the State Grid smart grid research center.

He said the company is promoting the use of battery-swap stations because they is more efficient than the charging points.

It takes three to five hours for a vehicle to become fully charged, but the whole battery-swap process only needs five minutes, Yao said.

"However, the cost of a swap-station is much higher because of the advanced energy-storage technology," said Yao. "The construction of a large-scale charging station costs 20 to 30 million yuan ($3.05-4.57 million) and a small-scale one costs less than 10 million yuan, but it costs more than 100 million yuan to build a battery-swap station."

Yao said there are fewer than 10 battery-swap stations in China at present, but they will become a trend.

According to the National Development and Reform Commission, China will have 500,000 electric vehicles by the end of 2015. State Grid plans to build 2,351 electric-charging and battery-swap stations with 220,000 charging poles to meet the development needs of electric-auto industry in the next five years.

However, analysts think that there will still be a shortage of charging and battery-swap stations.

The country definitely needs more if the electric-auto industry keeps developing at a high rate, said Xu Chao, an analyst at Changjiang Securities Co.

"Compared with the number of gas stations in a city, the number of charging stations is too small," he said. "Also, the development of the electric-auto industry depends on the government's policy in new energy-developmental guidance."

In addition to the expansion of the electric-charging networks, State Grid will also largely apply its smart grid technology into new-energy fields, such as wind power, this year.

According to the company, it invested 41.8 billion yuan in wind-power projects last year. The installed wind-power capacity within its scale of business now totals 28.26 million kilowatts (kW).

State Grid said installed wind-power capacity will reach 50 million kW this year with 20 million kW of newly added capacity with the application of the smart grid system.