HANOI, July 12 (Reuters) - Vietnam's national power grid operator EVN plans to buy excess power generated by solar panels on homes and offices to feed into its own supply, state media reported on Friday.

Deputy Prime Minister Tran Hong Ha has told the Ministry of Industry and Trade to work on a plan to buy the rooftop power, with a proposed offtake volume of up to 10%, online news provider VnExpress reported, citing a ministry statement.

The authorities are proposing a price of 671 dong ($0.0264) per kWh for the excess power from rooftop solar panels, the report said.

If approved, the price would be less than half the price of electricity EVN is buying from solar farms, it said.

Vietnam aims to have half of its office buildings and homes powered by rooftop solar panels by 2030, under a master power development plan approved by the government in May last year. The country has solar energy potential of up to 963 gigawatts (GW), according to the plan.

Vietnam has 103,000 rooftop solar projects with combined installed capacity of 9.5 GW, the VnExpress report said.

Last week, the government said it had issued a new decree to allow factories to directly buy electricity from renewable power suppliers via Direct Power Purchase Agreements. ($1 = 25,410 dong) (Reporting by Khanh Vu; Editing by Andrew Heavens and Jane Merriman)