‌The Silent Revolution: How Energy Storage Is Rewriting the Rules of Power

1. Energy Storage Systems Promote Renewable Energy Consumption

    Renewable energy sources, such as wind and solar, are intermittent and fluctuating, and their power generation is significantly affected by factors such as weather and seasons. This poses significant challenges to the stable operation of the power grid. When renewable energy is connected to the grid on a large scale, the random fluctuations in its output power increase the burden on the grid's peak and frequency regulation. Displacing some conventional generating units further weakens the grid's regulation capabilities.

        Energy storage systems act as a "bridge" between renewable energy and the grid, enabling time-shifted energy utilization. When renewable energy generation is in excess, such as on days with strong winds and abundant sunshine, energy storage systems store excess energy. When renewable energy generation is insufficient, such as at night or during periods of low wind, energy storage systems release the stored energy. This effectively mitigates the intermittent nature of renewable energy, ensuring its efficient grid integration and utilization, reducing wind and solar power curtailment, and increasing the utilization rate of renewable energy. Taking Gansu as an example, its installed capacity of new energy accounts for more than 61%, and the new energy storage grid-connected capacity reaches 3.14 million kilowatts/7.26 million kilowatt-hours. In 2023, the maximum charging power of energy storage will reach 1.73 million kilowatts, and the annual charging volume will be 575 million kilowatt-hours, which will greatly promote the consumption of new energy.

2. The Impact of Energy Storage Systems on Grid Stability and Flexibility

    Amidst the wave of energy transition, the power grid faces numerous challenges. Changes in the primary power source have resulted in lower minimum output from renewable energy sources, limiting their ability to support system power balance and power supply security. Furthermore, extreme weather conditions such as cold waves increase power supply demand, further increasing the challenge of ensuring security.

    Energy storage systems act as a stabilizer for the power grid, playing a significant role in enhancing its stability and flexibility. For peak load regulation, energy storage systems can charge during periods of low off-peak electricity prices and discharge during periods of high peak prices, alleviating power supply and demand constraints during peak and off-peak periods. For frequency regulation, energy storage systems, with their rapid response capabilities, can deliver full power within hundreds of milliseconds, meeting power conversion requirements within the frequency regulation timescale. This effectively reduces active power imbalances or regional control deviations in the power system, and allows them to participate in both primary and secondary frequency regulation. Energy storage systems can also improve power quality and provide uninterruptible power supply, ensuring a stable, high-quality power supply for users and enhancing the stability and flexibility of the power grid.

3. The Role of Energy Storage Systems in Power Peak and Frequency Regulation

    Electricity demand fluctuates constantly, with significant load differences between peak and off-peak periods. Traditional peak and frequency regulation relies primarily on highly dispatchable power sources such as thermal and hydropower generation. However, with the large-scale integration of renewable energy, this approach is no longer sufficient to meet demand.

    In this context, energy storage systems have become a crucial force in power peak and frequency regulation. Their operating principle is to use energy storage devices, such as batteries and supercapacitors, to convert electrical energy into other forms of energy and store it during periods of low power demand. When power demand peaks, the stored energy is converted back into electrical energy and released. In practice, when grid load is low, the energy storage system charges to store excess energy; when grid load is high, the energy storage system discharges to fill power supply gaps. For example, in a certain region's power system, the energy storage system charges during off-peak hours at night and discharges during peak hours during the day. This effectively balances power supply and demand, reduces the peak-to-valley difference in the grid, and improves the stability and economy of the power system.