In theory, TOU pricing should lower overall costs, but Dr. Nguyen Huy Hoach warns that badly designed tariffs may actually increase bills for many families. If the peak price is set too high and the off‑peak discount is insufficient, households that cannot change their usage timing will pay more.

The reason most families struggle to shift usage is that essential demand clusters in the evening. After work and school, people need lighting, cooking, bathing and other activities, which are tied to fixed daily routines. These activities cannot be moved simply because electricity becomes more expensive.

Households with flexible appliances such as washing machines, insulated water heaters or EV chargers can move their use to cheaper periods and therefore lower their electricity bills. These devices give owners the ability to follow price signals.

Dr. Hoach recommends that regulators first simulate household bills under different tariff options and run pilot programs before a nationwide rollout. By testing the price gap between peak and off‑peak hours, policymakers can avoid over‑burdening families while still providing a clear economic signal. Adjusting the gap based on pilot results helps keep the policy fair.

In short, most daily electricity needs happen at a time when rates are highest, so many households cannot escape peak prices under a poorly set TOU system. Careful design, testing and a reasonable price difference are essential to protect consumers and achieve the intended load‑shifting effect.