How does the energy storage system achieve dynamic capacity expansion

This paper proposes a capacity expansion model for multi-temporal energy storage in renewable energy base, which advantages lie in the co-planning of short-term and long-term storage resources. This approach facilitates the annual electricity supply and demand equilibrium at renewable energy bases and reduces the comprehensive generation costs.

With a step length of 500 MW, capacity expansion planning for energy storage is conducted across varying thermal power capacities. The results are shown in Fig. 10. Fig. 10. Planning results of energy storage under different thermal power unit capacities.

Nonetheless, as the installed capacity of thermal power continues to decrease and renewable energy bases face more severe challenges in supply balance over extended periods, long-term energy storage becomes indispensable. The demand for its capacity subsequently increases to address energy fluctuations over longer time scales. 4.3.2.

However, as the costs of long-term energy storage gradually decline to half of the forecasted costs, the demand for power capacity of long-term storage experiences a sixfold increase, while the requirement for short-term storage diminishes by 40 %, bringing the demand ratio of the two to a near equilibrium at approximately 1:1.

In the initial phase, when thermal power resources are abundant, long-term energy storage can maintain electrical supply balance by storing surplus power over extended periods and releasing it when renewable capacity is insufficient, thereby enhancing the peak-shaving capability of renewable energy bases.

In decarbonized power systems, the increasing energy demand necessitates long-duration energy storage. These storage technologies play a crucial role in managing the intermittent nature of renewable energy, offering grid flexibility, minimizing curtailment, and ensuring reliable and resilient power supply.