At the Workshop on the National Energy Master Plan (NEMP) recently held for the period 2021-2030, with a vision up to 2050, Deputy Minister of Industry and Trade, Mr. Dang Hoang An, requested the consulting and design agencies to carefully gather suggestions and recommendations from experts and businesses so that they can conduct a study based on both science and practical situations, to ensure that the NEMP can be built and implemented in a best way possible.  

Representatives of state management authorities required a clear analysis of the current implementation status of all existing master plans and any inadequacies in the implementation and deployment. Relevant bodies need to clarify the development of renewable energy sources (RES) in the National Electricity Development Strategy for the period 2021-2030, with a vision up to 2045 (Power Development Master Plan 8) which is being built concurrently and will be finalized and submitted to the Government by the end of this year.

According to Deputy Minister of Industry and Trade, Mr. Dang Hoang An, the Energy Institute - the consulting agency for both planning (Energy and Electricity Masterplan) needs to determine and carefully analyze the optimal energy structure of the economy. Because this is a particularly important factor, determining the proactiveness and ensuring national energy security as well as safe operation of the electrical system.

Power storage to ensure renewable energy generation systems. (Photo by KT)

One of the most “critical" elements of the energy structure as emphasized by Deputy Minister Dang Hoang An, that requires clarifying, is the required energy import ratio versus the domestic supply capacity. Specifically in the power sector, “How much RES is required? How is the energy storage system calculated when developing RES.

“We want to develop RES but without storage systems and quick start solutions, the electrical system can not work. Technically this is matter of fact,” said Mr. An.

According to experts in the energy sector, the current rate of RES in the new Vietnam Electrical system is about 10-12%, while the flexible power sources such as hydroelectricity and gas thermal power are still quite high, so it is not necessary to calculate the energy storage system. However, if the RES ratio is up to 20%, it is imperative to take into account the energy storage system to ensure the safe operation of the electrical system.

Dr. Nguyen Manh Hien - Former Director of the Institute of Energy said, according to many documents of the world, it is said that, if the development of RES rate is less than 20% of the total capacity of the whole system, there is no need for a power storage. but over 20%, one is required.

“If the development rate of RES is high but without a power storage, it will cause instability in the system. In the absence of wind or solar the system will lose an enormous amount of electricity. Therefore, it is stipulated that without a power storage system, the RES ratio must remain below 20% or less ”, Mr. Hien stated.

According to experts in the energy sector, with an open power masterplan, scenarios suggest that the ratio of RES could account for more than 30% by 2030 and more than 40% by 2045, among others. While traditional and flexible power sources decrease, the need for a reserved energy source to ensure safe operation of the electrical system is critical (when the sun/wind is down).

It is calculated that for every 1MW of RES development, at least 0.5MW of stored electricity is needed. According to the design of the draft Power Master Plan 8, the stored energy rate of less than 1.5% of the total capacity of the whole system is too low, and there exists a high risk for the system during operation.

Currently, there are 3 main types of storage sources, pumped hydroelectricity, supercapacitor and other types of battery storages (batteries or lithium batteries), among which, pumped hydroelectricity is considered as the optimal plan for the reserve of generating capacity, generating peak coverage, helping to stabilize the system, and adjust frequency.

To temporarily solve the problem of system regulation, in addition to flexible power sources such as hydroelectricity and gas power, in times of high electricity demand, Vietnam is using diesel generators to supplement sources. However, the cost of electricity generation from diesel sources is quite expensive, not to mention the higher mobilization will increase the amount of polluted gas emitted into the environment.

Energy storage structure.

Mr. Nguyen Van Vi, an energy expert of Vietnam Energy Association, said that the development trend of energy sources can be balanced by each region. To ensure the long term development, it is necessary to consider the plan of using the storage battery system as a mandatory requirement for investors in the renewable energy system.

“For example, in a family, when installing solar panels, it is required to have spare equipment to ensure balance. More broadly with a system, there must also be a requirement for a storage system as an integral condition”, recommended Mr. Vi.

According to many experts, for every variable RES, there must be an equivalent source of energy storage to ensure safe operation. The battery storage system has many benefits, making the operation of the power system more active with renewable energy due to the ability to "accumulate / buy back" in sunny / windy times with low prices to "sell up" to the system. system at peak / when needed.

At the Workshop on Power Master Plan VIII, requirements for energy storage systems including the use of battery storage were also taken into consideration. However, the issue of how much, the operating mechanism, and how the purchase / storage price were not taken into account. According to the experts’ evaluation, the storage ratio in the Power Planning VIII project is very low. Therefore, it is necessary to study and supplement the storage system so that when the Implementation Plan is put into operation, the electrical system must be operated safely.

Source: VOV