The Siam Electricity Company was first established as a private enterprise in 1898 by members of the royal family and senior officials, with most of the shares owned by the monarchy. The company set up its headquarters and the power plant on the grounds of Wat Ratchaburana Ratchaworawihan, which was commonly referred to as “Wat Liab,” giving the plant its well-known name, the Wat Liab Power Plant.

Electricity was generated using steam engines, with rice husks from local rice mills as a major fuel source. At first, power was supplied along important streets in the capital such as Tri Phet, Ban Mo, Sanam Chai, Bamrung Mueang, Charoen Krung, Yaowarat, and Sampheng. Electricity was mainly used for street lighting, the royal palace, and key public buildings.

Due to high costs and a lack of management expertise, the company suffered financial losses and collapsed in 1892. The government took over operations and, in 1897, granted a new concession to an American named L.E. Bennet. He later sold the concession to a Danish group led by André du Plessis de Richelieu. Under Danish management, the power supply was revived and successfully expanded. Electricity was supplied not only to government buildings and the public but also for Bangkok’s tram system.

In 1914, the Samsen power plant was established to further expand coverage, allowing reliable electricity supply throughout Bangkok and Thonburi. When the country changed its name to Thailand in 1939, the company became known as the Thai Electricity Corporation Ltd. During the Second World War, Bangkok suffered heavy bombing by Allied aircraft in April 1945. Both the Samsen and Wat Liab plants were damaged, leaving the city without electricity.

The Wat Liab plant continued operations until 1949, when its concession expired. Afterwards, the Bangkok electricity service was merged with the Samsen plant (operated by the Department of Public Works), and in 1958 the Metropolitan Electricity Authority (MEA) was established. The Wat Liab Power Plant stopped operating when the more modern Rama VI Power Plant opened, as it was capable of producing electricity for all of Bangkok and its surrounding areas.

The original Siam Electricity Company building still stands at the MEA Wat Liab District Office. It was listed as a registered historic building by the Fine Arts Department in 2020, and during 2025–2026 the building is being transformed into a museum to showcase the history of electricity in Bangkok.