How does energy storage achieve peak load regulation and frequency regulation?
With the rapid development of renewable energy, especially wind and solar energy, the power system is facing more and more challenges. Due to the intermittent anduating nature of wind and solar power generation, the stability of the power grid is facing greater tests. To address these challenges, energy storage systems play a crucial role in load regulation and frequency regulation. Energy storage technology can balance the power grid load, ensure the stability of the power grid frequency and voltage, and play a regulatory role the power supply and demand fluctuate.
1. What is peak load regulation?
Peak load regulation refers to the process of adjusting power generation to cope with fluctuations in electricity load, especially peak load periods, by providing sufficient electricity to meet demand through energy storage devices or other means. Peak load regulation mainly addresses the issue of uneven power demand. In daily, there is usually a difference in power demand between daytime and nighttime, especially during peak electricity consumption periods, such as when air conditioning loads are high in summer, the grid may experience insufficient power supply. Peak load regulation can ensure that the power grid provides sufficient power support during high-load periods, avoiding power outages caused by insufficient power
2. What is frequency regulation?
Frequency regulation refers to the process of maintaining the stability of the power grid frequency by adjusting the power generation and of the power grid. When the power grid experiences frequency fluctuations, frequency regulation can ensure that the frequency remains within a stable range by regulating the output of energy storage systems other power generation resources. The stability of the power grid frequency is crucial for the safe operation of the power system. Frequency fluctuations are usually caused by the instantaneous imbalance between demand and power generation capacity. When the power grid frequency is low, it is necessary to increase power generation, and vice versa. Frequency regulation mainly addresses the problem frequency instability, especially when large-scale renewable energy is connected to the power grid, frequency regulation is essential to ensure the stability of the power grid
Current frequency modulation technology includes primary and secondary frequency modulation: Primary frequency modulation refers to the use of the governor of the generator set to adjust the output the generator set according to the inherent load frequency characteristics of the system when the system frequency deviates from the standard value. Secondary frequency modulation is further adjustment on the basis primary frequency modulation to achieve more precise frequency control.
Frequency response in deep peak regulation method of thermal power: Not only the deep peak regulation is concerned, but also the frequency and inertia response are considered. constructing the power system dispatching model and solving it by convexification, the unit dispatching strategy is optimized to provide rapid frequency response.
New energy units participate in frequency regulation: With the large-scale access of renewable energy, new energy units (such as wind power generation) are also in the frequency regulation system. By evaluating the primary frequency regulation capability of new energy units, the frequency regulation reserve capacity undertaken by conventional units and new energy units is allocated ensure the frequency stability of the power grid.
2. How Energy Storage Achieves Peak Shifting and Frequency Regulation
1. The Role of Energy Storage in Peak Shifting Energy systems can regulate the load balance of the power grid by charging during periods of low electricity demand and releasing power during periods of high demand. Specifically, energy storage peak shifting mainly achieved through the following two methods: Charging and Discharging Process: Energy storage devices such as lithium batteries and pumped storage power stations can charge and store energy during of low electricity demand (such as at night) and discharge during periods of high electricity demand (such as during the day), thus effectively regulating the power grid load. for Renewable Energy Regulation: The power generation capacity of renewable energy is affected by factors such as weather. Energy storage systems can help balance these fluctuations. For example, when is an excess of solar power generation, energy storage devices can store the surplus electricity, and when solar power generation is insufficient, the energy storage system can release the stored to ensure stable power supply to the grid.
2. The role of energy storage in frequency regulation In terms of frequency regulation, energy storage systems achieve stability by responding quickly to the frequency of the power grid. Frequency fluctuations in the power grid are usually caused by load changes or generation changes, and the fast response capability of energy storage systems makes them ideal for frequency regulation. The specific implementation methods are as follows:
Fast response capability: Energy storage devices (especially battery energy storage systems) have extremely fast response speeds and can and discharge at the millisecond level, thus quickly compensating for the frequency fluctuations of the power grid. For example, when the frequency is low, the energy storage will quickly release the stored electricity to increase the power generation, and vice versa, it will charge. Auxiliary regulation: Energy storage systems can not only respond to large-scale changes, but also provide a fine-tuning function for frequency. By precisely controlling the discharge power of the energy storage device, the system can maintain frequency stability in a period of time.
3. Application scenarios of energy storage for peak load regulation and frequency regulation During peak load periods: Energy storage systems can quickly release electricity to the power gap in the grid, thereby alleviating the pressure during peak power consumption periods. Grids with large frequency fluctuations: In areas with a high proportion of renewable such as wind and solar power, the grid frequency is prone to fluctuations. Energy storage systems can help balance these fluctuations. Remote areas far from the main grid: In remote areas, energy storage can be used as a regulating means for local power systems, avoiding overloading of the grid or insufficient power supply.
4. Practical Cases of Energy Storage Peaking and Frequency Regulation in China 1. Jurong Pumped Storage Power Station in Jiangsu and Nong Pumped Storage Power Station in Jiangsu are typical energy storage peaking projects in China. With an installed capacity of 1.35 million kilowatts it has won "three world's firsts" in the field of pumped storage: the world's highest pumped storage dam, the world's highest roller-compacted concrete堆石 dam, and the world's largest pumped storage power station with the largest filling scale.
2. The 250MW/1GWh independent energy storage power station project in Luopu, Hotan, Xinjiang has construction. The 250,000-kilowatt/1,000,000-kilowatt-hour independent energy storage station project in Luopu, Hotan has started construction. The project will be implemented in two phases, with the first phase of 600MWh to be connected to the grid for power generation on April 30, 2025. The project has a planned capacity of 250,00 kilowatts/1,000,000 kilowatt-hours. As a grid-forming independent energy storage power station, it will the needs of peak load regulation, frequency regulation, active voltage/reactive power support, primary frequency regulation, black start, and inertia response in the Xinjiang power grid completion, ensuring the safe, stable, and reliable operation of the Xinjiang power grid, enhancing the flexible regulation capability of the power grid, and promoting the consumption of energy.
3. CEC Energy Storage Huhehaote Ketown Project Successfully Completes Backfeeding On November 1st, the first batch independent new energy storage power station demonstration projects in Inner Mongolia - the Huhehaote Ketown 100MW/400MWh grid-side energy project - successfully completed backfeeding. It is reported that the project uses a lithium iron phosphate battery energy storage system, with the system supplier being CEC Energy Storage, the general contractor for the construction is Jiangsu Institute. The grid-side energy storage power station project was completed with the power supply to the booster area at around midnight October 31st, and on November 1st, the power supply to the energy storage area was completed. The project is located in Ketown, Wuch County, Huhehaote City, Inner Mongolia Autonomous Region. It is the first lithium iron phosphate sodium-ion hybrid energy storage power station in the Inner Mongolia region and it is also the first successful application of sodium-ion energy storage system by Jiangsu Institute. The construction scale of the project is 100MW/40MWh, including a lithium iron phosphate battery energy storage system of 97.5MW/390MWh and a sodium-ion energy storage system 2.5MW/10MWh.
