Mr. Nguyen Huu Chinh
- Reporter: Dear Sir, why are we doing research, calculation to expand Tuyen Quang Hydropower Plant on Gam River?
- Mr. Nguyen Huu Chinh: Tuyen Quang Hydropower Plant was built to serve three main tasks, including: Creating a capacity of 1 billion m3 reservoir to prevent floods for the Red River Delta and Tuyen Quang township (now is Tuyen Quang City); create power supply source for the national grid; supply water in the dry season for the Red River Delta. Thus, for Tuyen Quang Thermal Power Plant, the task of generating power is only secondary, but the plant has contributed a large amount to the national power system with an installed capacity of 342MW, the average annual power output is nearly 1.33 billion kWh.
In fact, after 11 years of Tuyen Quang Thermal Power Plant put into operation (2008 - 2019), only 3 years in which Tuyen Quang hydroelectric reservoir did not discharge flood due to the very dry weather. In the remaining years ( 8 years), the reservoir discharged 1 to 3 times/year, especially in 2017, the reservoir discharge 6 times. For the years of flood discharge, we can easily determine the value of energy lost, causing waste of resources and decline in revenue. This is also the basis for us to consider expanding the plant.
- Reporter: When expanding Tuyen Quang Thermal Power Plant, what benefits can we gain, sir?
- Mr. Nguyen Huu Chinh: The value of hydroelectricity is not merely the output of power (the number of kWh) generated, but also the value of the capacity to meet in the electricity system and the ability to run frequency modulations. The power output meets required quantity, and the capacity and frequency modulation meet required quality. Quantity and quality both play an important role in electricity operation. However, quality requirements are increasingly high, especially in the period of economic development. When exploiting the excess discharge energy, we have contributed more water energy of each river to the electricity system, but also supply additional capacity to the system, meeting peak load and prevent incidents, increasing frequency modulation capability for the system. If Tuyen Quang Hydropower Plant is expanded, it will partly meet that requirement.
The number of "peak" load hours of Vietnam's power system ranges from 2,000 - 2,500 hours/year, hydroelectric plants are eligible for "peak" operation, so the number of hours using capacity set within the range should be selected. This is so effective. Only hydropower plants with large enough reservoirs - long-term regulation are eligible to participate in the "peaking" operation. Tuyen Quang Hydroelectricity has a large enough reservoir, fully capable of participating in "peak cover" operation, so it needs to be expanded to increase the capacity of the system.
Overview of Tuyen Quang Hydropower Plant
- Reporter: According to the calculation of PECC1, if Tuyen Quang Hydropower Plant to be expanded, what is the suitable rate of the expected capacity, sir?
- Mr. Nguyen Huu Chinh: The current suitable capacity for expanding Tuyen Quang Hydropower Plant is about 100 - 150MW, which corresponds to an additional power output of about 37.6 - 43 million kWh in the flood season and conversion of power from off-peak hours (VND 700/kWh) to peak hours (VND 2,658/kWh) from 88 to 120 million kWh. As a result, the benefit brought about by the project was so significant. This is a supplement to the electricity system of about 37.6 to 43 million kWh in the flood season, reducing the overall cost of power generated by the system by taking up the "peak" load compared to using other generation sources, and increasing the power backup capacity for incidents.
- Reporter: In your opinion, what are advantages and disadvantages in implementing this project?
- Mr. Nguyen Huu Chinh: There are many advantages, PECC1 is a design consultancy unit of Tuyen Quang Thermopower Power Plant, so there are sufficient design documents made previously. PECC1 engineers have known well about the project, practical field conditions, such as geological, hydrological and site conditions. Currently, Tuyen Quang Thermopower Plant supports it and EVN also agrees to the research deployment plan. Most importantly, Vietnam's power system is in urgent need of new hydropower source capable of generating large capacity to cover peak power, because the renewable energy sources participating in the power system are increasing, but the risks are also high due to its dependence on natural conditions.
The biggest difficulty in conducting research to expand Tuyen Quang Hydropower Plant as well as other expanded hydropower projects is the power pricing mechanism for the expanded thermal power. The objective of the expanded Tuyen Quang Thermal Power Plant is to convert the power from off-peak hours that the plant is currently generating to peak hours (covered by the peak of the load curve), so the price of the extended power plants must be calculated at a rate of peak-hour load of the system.
However, up to now, there has been no official decision on peak and off-peak electricity prices applicable to expansion projects (especially projects > 30MW), so determining the economic efficiency of the project is very difficult. This is the point where the management mechanism has not kept up with the actual needs of the Vietnamese electricity system.
- Reporter: Thank you, sir!
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To implement the project, PECC 1 recommends:
- State management agencies should promulgate policies on electricity prices for expanded hydropower projects, creating a legal corridor as a basis for calculating economic efficiency of power projects.
- EVN and Tuyen Quang Hydropower Company will soon study plans of expanding the plant so that when there is official legal procedure, it can soon be implemented.
- The unit formulating the Electricity Plan VIII should soon add new sources of expanded hydropower projects to the plan, ensuring the safety of the whole system as well as the basis for plants to be deployed right after gaining approved policy of all competent authorities.
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