Construction of the plant was executed by the State Grid Corporation of China and represents a total cost of about $47.1m, reports Xinhua news agency.
Minister of Industry, Mines and Energy Suy Sem said the project was constructed is a part of a 30-year build- operate-transfer concessional contract signed by the Cambodian government.
Cambodia Prime Minister Hun Sen noted that construction of the plant was completed last year and that it is noteworthy achievement for the country with investments coming from China.
"In the context of globally soaring oil price, electricity generated by hydropower plants is a sustainable source of electric power supply," Sen added.
The facility will generate 78 million kWh of electricity per annum and it will sold to the Electricity of Cambodia at $7.91 cents per kWh.
The Kirirom III Hydro Power plant is the third project to be developed by Chinese investors in Cambodia.
