Vietnam adjusts peak and off-peak hours for electricity usage

Electric peak hours are shifted to the evening from 17:30 to 22:30 on weekdays, while off-peak hours run from 00:00 to 06:00 daily. The Ministry of Industry and Trade issued Decision 963, changing the peak, off-peak, and normal hours of the national power system. Under the decision, peak hours apply on weekdays (excluding Sundays) from 17:30 to 22:30, totaling five hours per day. Normal hours consist of two blocks, from 06:00 to 17:30 and from 22:30 to 24:00, for 13 hours per day. Off-peak hours run from 00:00 to 06:00 daily. On Sundays there is no peak period; normal hours run continuously from 06:00 to 24:00. Thus these time blocks differ from the current arrangement. Currently, peak hours are split into two blocks covering daytime and evening (9:30–11:30 and 17:00–20:00). Off-peak runs from 22:00 to 04:00 the following morning, with the remainder being normal. According to the decision, EVN will implement the time blocks across the system. Before December 15 each year, or when there are significant changes in electricity demand, EVN must report to the Ministry of Industry and Trade to propose appropriate adjustments. NSMO—the National System Operations and Market Management Company—coordinates data on capacity, output, and system operation to provide a basis for calculating and determining the time blocks. The unit is also responsible for reporting and proposing adjustments when necessary. Electric sector staff are inspecting equipment. Photo: Ngoc Thanh Time blocks for electricity usage are a key basis for calculating electricity prices by time of use. Typically, peak hours carry the highest price, off-peak the lowest, encouraging customers to shift consumption. This regulation mainly applies to customers in manufacturing and business sectors under time-of-use pricing. About 1.25 million electricity meters nationwide currently operate under this mechanism, directly affecting metering, billing, and energy payments. Previously, the Ministry of Industry and Trade said adjusting the time blocks is necessary to reflect the evolving supply-demand dynamics, especially as the share of renewable energy such as solar and wind grows. In practice, the current peak, off-peak, and normal-hour structure has been in place for 12 years. Since 2019, the supply-demand balance has changed significantly with the rapid rise of solar energy and renewables. The share of industrial electricity demand rose from about 30% to more than 50%, while residential demand fell from about 50% to nearly 33%. These changes lead to pronounced fluctuations in electricity demand at different times of day, making the current blocks less suitable over time. The agency also argues that properly defining peak, off-peak, and normal hours will help improve the efficiency of the electricity system. Through time-of-use pricing, customers are given incentives to adjust consumption, reduce use at peak times, and shift to off-peak or normal periods, thereby optimizing costs and reducing system pressure. Phuong Dung