To strengthen the future growth of the public and private sectors, Wang Noi Power Plant is the first and the only power plant in the area of generating capacity and transmission system development of the Lower Central region. The power plant has supported the economic infrastructure development bringing prosperity to the region and giving services to expanding suburban areas.

Wang Noi Power Plant is an urgent project proposed by the National Economic and Social Development Council. The cabinet acknowledged the approval of the project on July 12, 1994. Wang Noi District in Phra Nakhon Si Ayutthaya Province is selected to be the site as it is a potential area near the fuel source, water source, transmission system, and the center of electricity demand, such as the Bangkok Metropolitan Region. This site selection can reduce the cost and power loss in the transmission system. It uses natural gas from the Gulf of Thailand via Bang Pakong – Wang Noi gas pipeline of about 100 km and from Myanmar.

The construction of Wang Noi Blocks 1-3 began in November 1994 and was completed on April 28, 1998. The opening ceremony of the Wang Noi Power plant was inaugurated by His Majesty King Maha Vajiralongkorn Phra Vajiraklaochaoyuhua on August 7, 1998.

Later, the rapid economic and industrial growth resulted in the rising demand for electricity in the Central part of the country. EGAT therefore developed a new power source to strengthen the security of the electricity system in line with the Power Development Plan (PDP2010). Wang Noi Power Plant Block 4 was then constructed at the former site in December 2011 and was completed on April 7, 2014, suppling electricity to the system since May 2014.

(Block 3 with a generating capacity of 686 MW was decommissioned on May 31, 2023.)

At present, Wang Noi Power Plant has a contracted generating capacity of 750 MW:

• Block 4 with a generating capacity of 750 MW