(i)Current status of Vietnam's power system with high RE (solar and wind power) rate, and the capacity of RE projects is greatly fluctuated. (ii) Advantages and disadvantages of operating a power system with a high RE rate. (iii) Demand and necessity of electricity storage in the current and future power system of Vietnam.
Bac Ai pump-storage hydropower with a capacity of 1200MW is the largest power storage project that EVN makes investment with expectation to be put into operation in 2026.
In the world, at present, beside pump-storage hydropower plant for peak covering, the lagest power storage system reachs only 150 MW and same projects with 500 -600 MW are developing in Australia. III. A number of proposals for energy storage development:
According to international energy experts, when RE electricity rate reachs 15% up, the investment in energy storage system is economically efficient. So, in many countries over the world, the energy storage systems have become the necessary technologies in demand side management, RE and smart grid development.
II.Challenges in energy storage development: Although the costs of storage batteries and technologies are reducing, they are still high, especially for batteries with up to 4 hours of energy discharge per charge-discharge cycle.
Solar and wind power investors can only invest in small-scale storage batteries to store a small part of the generating electricity at times of RE reduction and discharge it to the system at peak hours for reducing losses of the investors due to RE electricity cutting.