Da Nhim Hydropower Plant: A Symbol of Vietnamese-Japanese Friendship

The Da Nhim hydroelectric power plant is one of the first hydroelectric projects built in Vietnam, belonging to the uppermost stage, exploiting the enormous hydroelectric potential of the Dong Nai River system. The project is considered a beautiful symbol of Vietnam-Japan friendship.

Young engineers at the Da Nhim hydroelectric power plant. Photo: Nguyen Thao.

A symbol of friendship.

The Da Nhim hydroelectric power plant (Ninh Thuan province) was started in January 1962 and completed in December 1964 with funding from the Japanese government. The plant has a total designed installed capacity of 160 MW, consisting of 4 generating units, with an average annual electricity output of approximately 1 billion kWh.

To have the power plant as it is today, countless young engineers from Japan and Vietnam have laid down their lives for the sake of electricity in the South. "Even though 50 years have passed, the plant's staff and workers are always grateful to those who fell for the sake of electricity for the South," said Mr. Nguyen Trong Oanh, General Director of Da Nhim - Ham Thuan - Da Mi Hydropower Joint Stock Company.

According to Mr. Oanh, during the war, the plant sometimes ceased operation due to damaged pipelines. Throughout this period, the plant operated only to maintain the generating units and supply electricity to South Vietnam, albeit in small quantities.

After 1975, the local engineers and workers who remained to maintain the factory, along with technical staff from the North, focused on restoring the factory to stable operation within six months. This was a very difficult period, but it demonstrated the capabilities of Vietnamese engineers and workers.

From 1975 to 2000, the Da Nhim hydroelectric power plant was an independent unit within Power Company 2, later the Vietnam Electricity Group (EVN). Thanks to the efforts of its engineers and workers, the plant maintained stable operation despite shortages of materials and equipment, especially during the embargo period when importing machinery and equipment was very difficult.

In 1996, the Vietnamese government decided to allocate $66.54 million to renovate equipment and power lines, including 7 billion Yen (equivalent to $48.6 million) as a preferential loan from Japan, $2.9 million as domestic counterpart funding, and the remainder from other international donors.

Since the end of 2000, the Da Nhim hydropower plant has merged to form the Da Nhim - Ham Thuan - Da Mi plant complex, a new model developed by the Vietnam Electricity Corporation. Leveraging the advantages of human resources, management experience, and skilled technical staff and workers from Da Nhim, the Ham Thuan - Da Nhim plant complex has been taken over.

Next, in 2005, the Da Nhim power plant underwent restoration after 40 years of operation. The restoration included replacing the generator stator, support bearings, excitation system, transformers and generator control system; replacing the turbine, main valve, speed control system, pressure-controlled oil supply system and hydraulic mechanical equipment system; hydrological data collection system and the 230 kV Da Nhim - Long Binh transmission line.

Funding was borrowed from the Japan International Cooperation Bank. The project was fully restored in 2008 with a total cost of VND 620 billion. The contractors selected to carry out the plant restoration project included a joint venture between Mitsubishi Electric and Mitsubishi Electric of Japan; Sojitz and Toshiba of Japan; Tecapro Vietnam and Vaisala of Finland. The main consultant for the project was Nippon Koei of Japan.

According to Mr. Nguyen Trong Oanh, General Director of Da Nhim - Ham Thuan - Da Mi Hydropower Joint Stock Company, this project symbolizes the friendship between Vietnam and Japan. The project has very good and stable construction and equipment quality.

"It can be said that the Vietnamese took over a very advanced project at that time, and the management level during that period was very high. Currently, there are no major issues related to the equipment; the generating units are operating at very high rated capacity, averaging 7,000-8,000 hours per year per unit," Mr. Oanh said.

Mr. Nguyen Ngoc Quang, former Deputy Director of the Da Nhim hydroelectric plant, also assessed that, in the past, Da Nhim was the number one hydroelectric project in Southeast Asia.

Still glorious after 50 years.

To date, the Da Nhim - Ham Thuan - Da Mi hydropower plant manages and operates 13 generating units with a total capacity of 642.5 MW. The average annual electricity output is 2.6 billion kWh. Due to the consistent flow of water from Da Nhim down the Pha River, besides supplying water to the Ninh Thuan delta and Phan Rang city, the potential for hydropower development remains significant. With such a stable flow, I believe that in the future, there is still good potential for developing smaller hydropower plants downstream.

According to Mr. Oanh, regarding future projects, the Da Nhim - Ham Thuan - Da Mi Hydropower Company has reached an agreement with JICA (Japan) to finance the expansion project of Da Nhim with an additional 80 MW unit. Construction is expected to begin in 2014, with power generation scheduled for 2016. The additional 80 MW will alleviate the strain on electricity supply in the southern region.

Mr. Oanh stated that the Da Nhim expansion project, currently under agreement with JICA, is expected to have a total investment of approximately 1,900 billion VND, with JICA financing 85% and the company contributing 15%.

JICA has been very supportive, actively sending delegations over the course of a year, leading to a final agreement. The loan agreement between the two governments is expected to be signed by the end of September 2013. JICA representatives visited the Da Nhim-Ham Thuan-Da Mi hydropower plants and highly praised the management capabilities and quality of the three plants.

Mr. Oanh stated that the experience in expanding the plant stems from the future trend of hydropower. When the proportion of hydropower, thermal power, and nuclear power is adjusted, the situation for hydropower plants will change. For example, the Da Nhim hydropower plant is currently operating almost continuously, running at low power, but in the future it will shift to running at high power. Therefore, we can absolutely continue to expand the plant's capacity.

According to Tien Phong - PH