Abstract: With the continuous development of the social economy, China’s new energy power generation system has undergone rapid development. The application of energy storage technology on the new energy generation side is becoming increasingly widespread, which also has a positive impact on its own development. Based on this, starting with the application advantages of energy storage technology on the new energy generation side, this article analyzes in detail the key technologies of energy storage on the new energy generation side and proposes application paths for energy storage technology on the new energy generation side, aiming to provide references for the research and application of energy storage technology on the new energy generation side in China.
1. Introduction
With the growing global demand for clean energy, new energy power generation has become the direction of development for the contemporary power industry. However, new energies such as wind and solar power possess intermittency and uncertainty, posing challenges to the stable operation of power systems. To this end, the application of energy storage technology has become crucial for ensuring smooth power system operation. Energy storage technology on the new energy generation side provides a powerful tool for power systems, playing a key role in maintaining grid stability and efficiency under high penetration rates of new energy sources.
2. Advantages of Energy Storage Technology on the New Energy Generation Side
2.1 Reducing Grid Operation Costs
Energy storage technology on the new energy generation side significantly reduces grid operation costs in practical applications. Grid operation costs encompass various fees, with scheduling and maintenance costs being the most critical. Energy storage technology effectively balances mismatches between generation and load, thereby reducing frequency fluctuations and voltage instability caused by such mismatches. Without energy storage, the grid needs more frequent scheduling to ensure a balance between electricity supply and demand, which increases equipment wear and dependence on high-priced reserve capacity. Energy storage provides a buffer for the grid, making grid scheduling more flexible and reducing scheduling frequency, thereby significantly decreasing scheduling costs. Energy storage can also provide rapid emergency response, reducing losses due to power accidents and further saving maintenance and restoration costs. Additionally, by reducing reliance on traditional generator sets, energy storage technology lowers fuel consumption and related transportation costs for the grid. In summary, energy storage technology on the new energy generation side brings efficiency improvements to grid operations, significantly reducing grid operation costs, and is crucial for the robustness and economy of the entire power system.
2.2 Optimizing New Energy Power Systems
The introduction of energy storage technology on the new energy generation side plays a key role in optimizing new energy power systems. New energy sources such as wind and solar power are unstable and unpredictable. Without energy storage, this instability may lead to grid frequency fluctuations and voltage instability, affecting power system stability and safety. The addition of energy storage provides a means of energy buffering for new energy power systems, ensuring smooth grid operation. Furthermore, new energy output is influenced by various factors such as sunshine and wind speed, causing significant variations in electricity generation across different time periods. Energy storage technology stores excess electricity when new energy generation is abundant and releases it when generation is low, thus ensuring a stable electricity supply. This balancing strategy significantly improves new energy utilization efficiency and grid operation efficiency. Meanwhile, by adjusting the charging and discharging strategies of energy storage devices, grid demands can be better met, further optimizing system operation, reducing dependence on traditional generator sets, minimizing startups and shutdowns and related wear, and enhancing overall system economic benefits. Therefore, the application of energy storage technology on the new energy generation side in power systems not only ensures system stability but also contributes significantly to improving new energy accommodation rates and the economy of the overall power system.
3. Key Technologies of Energy Storage on the New Energy Generation Side
3.1 Electrochemical Energy Storage Technology
Electrochemical energy storage technology is one of the core technologies for energy storage on the new energy generation side, primarily including various types of secondary batteries and supercapacitors. Among them, lithium-ion batteries are widely concerned due to their high energy density and long cycle life. Their working principle involves lithium ions moving between the positive and negative electrodes during charging and discharging. Common positive electrode materials include ternary and lithium iron phosphate, while negative electrode materials are mainly graphite and silicon-based materials. Additionally, solid-state battery research is gaining traction, with solid electrolytes replacing traditional liquid electrolytes to effectively improve battery safety. Supercapacitors, also known as electrochemical double-layer capacitors, store energy based on the physical adsorption process between electrodes and electrolytes. They possess high power density and can charge and discharge within extremely short periods. When selecting electrolytes and electrode materials, their electrical conductivity, stability, and compatibility with electrodes must be considered. Finally, the Battery Management System (BMS) for electrochemical energy storage is also a crucial component of key technologies, primarily responsible for monitoring battery status, protecting batteries from overcharge, over-discharge, and other hazards, and optimizing battery operating conditions to extend their lifespan.
| Type | Lithium-ion Batteries | Supercapacitors |
|---|---|---|
| Working Principle | Lithium ions move between electrodes | Physical adsorption between electrodes and electrolytes |
| Advantages | High energy density, long cycle life | High power density, fast charging and discharging |
| Applications | Wide range, including electric vehicles and stationary storage | Backup power and peak shaving |
3.2 Mechanical Energy Storage Technology
Mechanical energy storage technology mainly utilizes physical mechanisms to store and release energy. Common mechanical energy storage technologies include flywheel energy storage, compressed air energy storage (CAES), and pumped hydro storage.
- Flywheel Energy Storage: Converts electrical energy into rotational kinetic energy of a flywheel for storage. When energy is needed, the flywheel works as a generator to convert kinetic energy back into electrical energy. To minimize energy loss, flywheels often rotate in a vacuum and use magnetic levitation technology to reduce friction.
- Compressed Air Energy Storage (CAES): Uses an electrically driven compressor to compress air and store it in underground salt caverns or other enclosed spaces. When power is required, the compressed air is released and drives a turbine generator for electricity generation. This process can be combined with gas turbines to improve release efficiency.
- Pumped Hydro Storage: A mature large-scale energy storage technology. It works by using electricity to drive pumps to move water from a lower elevation to a higher reservoir when power is abundant. When power is needed, the stored water is released, and its potential energy drives turbine generators to produce electricity.
Each technology has its unique application scenarios and technical characteristics, and selections should be based on specific application needs and economic benefits.
| Type | Flywheel Energy Storage | Compressed Air Energy Storage (CAES) | Pumped Hydro Storage |
|---|---|---|---|
| Working Principle | Converts electrical energy to rotational kinetic energy | Compresses air for storage and later uses it to drive turbines | Uses pumps to move water uphill for potential energy storage |
| Advantages | High response speed, long cycle life | Large storage capacity, suitable for long-duration storage | Mature technology, large-scale storage capacity |
| Applications | Frequency regulation, backup power | Peak shaving, load leveling | Baseload power, peak shaving |
3.3 Electromagnetic Energy Storage Technology
Electromagnetic energy storage technology mainly involves superconducting energy storage and supercapacitors.
- Superconducting Energy Storage (SMES): Utilizes superconducting coils that have almost no resistance at low temperatures to store electrical energy. When superconducting coils are excited by a DC power supply at low temperatures, current continuously flows, creating a persistent magnetic field for energy storage. When energy is needed, the magnetic field drives current back into the grid. The main challenge lies in maintaining the low temperature required for superconductivity, which necessitates refrigeration technologies such as liquid nitrogen or liquid helium.
- Supercapacitors: Work similarly to traditional capacitors but differ in structure and materials to achieve higher energy density. Their energy storage mechanism is mainly based on electrochemical double-layer adsorption between electrodes and electrolytes. Since their energy storage mechanism is primarily physical adsorption, they offer faster charging and discharging speeds and longer cycle lives compared to traditional battery technologies. Supercapacitors typically use activated carbon as electrode material, with its microporous structure providing a large surface area for the electrolyte, thus increasing energy density.
Both superconducting energy storage and supercapacitors in electromagnetic energy storage technology exhibit rapid response and high efficiency. Different application scenarios select suitable electromagnetic energy storage solutions based on their specific technical characteristics and economic benefits.
| Type | Superconducting Energy Storage (SMES) | Supercapacitors |
|---|---|---|
| Working Principle | Uses superconducting coils to store energy in magnetic fields | Electrochemical double-layer adsorption |
| Advantages | High energy density, fast response | High power density, long cycle life |
| Challenges | Maintaining low temperature for superconductivity | Cost and energy density |
| Applications | Frequency regulation, power quality improvement | Backup power, short-duration energy storage |
3.4 Wide-Area Energy Storage Dispatch Technology
Wide-area energy storage dispatch technology primarily refers to technical means for centralized dispatch and management of multiple energy storage devices or systems in large-scale, cross-regional power grids. Its core objective is to ensure grid stability and reliability while improving grid operation efficiency.
Firstly, wide-area energy storage dispatch relies on high-speed, reliable communication technologies. Technologies such as optical fiber, satellite communication, and 4G/5G are commonly used to ensure real-time data transmission and processing. The real-time nature of data is fundamental to wide-area energy storage dispatch, as the state of the power grid is constantly changing, and only by obtaining real-time data can correct dispatch decisions be made.
Secondly, data acquisition and analysis are crucial components in the wide-area energy storage dispatch system. This requires the deployment of numerous sensors, smart meters, and other devices to monitor grid status, electricity demand, energy storage device status, and other information in real-time. Data analysis employs advanced algorithms, such as machine learning and artificial intelligence, to predict grid demand and potential risks, thereby supporting dispatch decisions.
Furthermore, wide-area energy storage dispatch necessitates comprehensive security mechanisms. This not only refers to communication security but more importantly, grid security. The dispatch system must incorporate fault detection and recovery mechanisms to ensure rapid response in the event of a fault, preventing larger-scale grid accidents.
In summary, wide-area energy storage dispatch technology is a strategic approach to managing and optimizing energy storage resources across large-scale, cross-regional power grids. By leveraging advanced communication technologies, real-time data analysis, and robust security mechanisms, this technology enhances grid stability, reliability, and operational efficiency, ultimately contributing to the seamless integration of renewable energy sources into the power grid.