Why is it necessary to increase the capacity of hydropower plants?

In the context that many renewable energy sources (renewable energy) are put into operation, creating significant challenges in power system operation. How significant is the expansion and increase in capacity of existing hydropower plants?

Improving power quality

Mr. Nguyen Huu Chinh - General Director of Power Construction Consulting Joint Stock Company 1 (PECC1) said that the main sources of power generation in Vietnam's power system today are from coal and gas-fired thermal power plants and other hydropower plants. In 2018, hydropower output contributed significantly to the power system, accounting for about 47%, the figure in 2019 is more than 41%.

However, the value of the expansion of hydropower projects is not in the additional power output for capacity increase, but in the value of available capacity, the ability to participate in peak coverage or support the power system in a quickest way. Along with that, the economic efficiency shown in the power output from the capacity increase can convert the use mode from off-peak hours to peak hours. All other economic values such as frequency regulation, voltage stabilization, etc., of hydropower power plants have not been taken into account.

According to the power demand forecast by 2030, the total power capacity of the whole system shall reach about 131,000MW, of which hydropower will only account for about 20% and wind and solar renewable energy sources will account for about 20%.

Tuyen Quang Hydropower Plant will be studied and expanded in the near future.

A need to promptly approve the policy 

Currently, hydropower plants are exploited according to the economic targets of previous years with the number of hours of using capacity of about 4000h/year. This index is no longer rational because the structure of power sources and the cost of electricity in the power system has changed. Mr. Nguyen Huu Chinh said: “Experience from developed countries around the world shows that the number of hours of economic exploitation for hydropower is about 2,500-3,000h/year depending on the nature and structure of the power sources. On the basis of Vietnam's power source structure by 2030, hydropower only accounts for nearly 20% of the power system. Thus, hydropower plants are increasingly shifting the operating time to the peak load graph (reducing operating time, increasing capacity) to enhance its advantages, while thermal power sources will undertake the bottom-level part".

Therefore, the number of hours of hydropower capacity use tends to decrease to 2000h/year, equivalent to the average number of peak load hours in the year. The investment in the expansion of a number of hydropower plants, if favourable, will allow to additionally provide peak coverage capacity for the power system, reaching a rational level in the use of Vietnam's existing renewable energy resources.

Voltage regulation time of power sources:

• 15/06/2021 07:33
• Evn.com.vn
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