The electricity grid is being upgraded to help combat smog in major cities.

As of January, China had completed the construction of five ultrahigh-voltage transmission lines; two more had been submitted for approval and another six were in the pipeline, an official from the State Grid said recently.

"The ultrahigh-voltage transmission lines can transmit power from western China to the east, optimize the energy distribution system, increase efficient use of clean energy and improve the eco-environment in Central China," said Zhang Zhengling, deputy director of the State Grid's development-and-planning department.