The Metropolitan Electricity Authority (MEA) says it will continue putting power lines underground, expecting to bury another 127 kilometres by 2020.
The agency plans several other power line projects in addition to those already initiated, said MEA governor Somchai Roadrungwasinkul.
The first phase of the plan, spanning 39 roads in Bangkok, Samut Prakan and Nonthaburi, was granted an investment budget of 48.7 billion baht earlier this year.
Mr Somchai said 90km of the total 127km are on roads located on the routes of the newly approved electric train lines, which will facilitate the construction of the underground power lines when they start developing the electric train lines.
The MEA in March started construction of underground power lines in Samsen and around Chitralada Royal Villa. The project is expected to take four years and is due to be finished in 2019.
This year, the MEA also plans to start power line projects in Teparak-Sukhumvit alongside the skytrain extension and in Wong Wian Yai-Arun Amarin to complement the extension of Arun Amarin Bridge.
The first phase is scheduled to be completed in 2025.
The MEA's plan for the second phase covers power lines on several streets with a total length of 134.3km. Construction is expected to start in 2017.
Mr Somchai said the MEA began putting power lines underground in 1984, with 40.6km of power lines put underground with a total investment budget of 2.17 billion baht. The projects were in the Silom, Pathumwan, Chitralada, Phahon Yothin, Phaya Thai and Sukhumvit areas.
In the first six months of 2016, the MEA generated revenue of 99.1 billion baht, up 10% year-on-year, for a profit of 6.3 billion baht.
As a result, the agency expects a full-year net profit of 10 billion baht as forecast earlier, Mr Somchai said.
The increase in revenue and profit was attributed to rising electricity demand among consumers, especially during the hot season when power demand for air conditioners is higher, he said.