With the heightened global awareness of climate change and environmental protection, the development and utilization of renewable energy have become crucial strategies for countries worldwide. Renewable energy storage technology, as a pivotal link in the renewable energy industry chain, not only effectively addresses the issues of volatility and intermittency in renewable energy generation but also enhances the overall efficiency and reliability of energy systems. This article delves into the definition, classification, application scenarios, revenue models, and future trends of renewable energy storage, providing both Chinese and English expressions for key terms.

Renewable Energy Storage (or New Energy Storage) refers to the use of specific technologies to store electrical energy or other forms of energy generated by renewable energy sources for release when needed. Based on the storage medium and technology, renewable energy storage can be categorized into several types.

Electrochemical storage is one of the most common forms of renewable energy storage, primarily realizing the mutual conversion between electrical energy and chemical energy through reversible electrochemical reactions between different materials inside batteries. Lithium-ion Batteries, Flow Batteries, and Sodium-ion Batteries are representative technologies in electrochemical storage.

CAES stores excess electrical energy by compressing air, effectively addressing large-scale energy storage issues. This technology has lower construction and operating costs but faces challenges such as dependence on fossil fuels and the need for large air storage chambers.

Flywheel energy storage uses an electric motor to drive a flywheel to rotate at high speeds, converting electrical energy into mechanical energy for storage. When needed, the flywheel drives a generator to produce electricity. This technology boasts a long lifespan and is pollution-free but incurs high costs in ensuring system safety and reducing flywheel loss.

Hydrogen energy storage offers advantages such as cleanliness, low carbon emissions, long storage times, and long transportation distances, making it advantageous in scenarios involving large-scale and long-distance energy storage and transportation.

In addition to the aforementioned technologies, emerging storage solutions include supercapacitor storage, superconducting storage, metal-air batteries, aqueous batteries, and liquid air energy storage. These technologies also exhibit unique advantages in specific application scenarios.

Renewable energy storage finds widespread application across various sectors, including residential, commercial, industrial, generation-side, grid-side, and microgrid-side.

In residential settings, renewable energy storage is primarily used to enhance power quality, ensuring the stability and reliability of household electricity use. By installing residential energy storage systems, families can utilize stored energy during peak demand periods, reducing electricity bills.

In commercial settings, renewable energy storage is mainly used for peak shaving, valley filling, and backup power. With energy storage systems, commercial users can charge during low-price periods and discharge during high-price periods, achieving cost savings. Additionally, these systems serve as backup power to ensure business continuity during power outages.

In industrial settings, the application of renewable energy storage is even more extensive. Besides peak shaving, valley filling, and backup power, storage systems can also be used for dynamic capacity expansion, enhancing industrial production flexibility and efficiency.

On the generation side, renewable energy storage is primarily used for ancillary peak shaving, frequency regulation, and smoothing renewable energy output. Through storage systems, the pressure on renewable energy consumption can be alleviated, improving forecasting capabilities and shifting peaks to enhance utilization rates.

On the grid side, renewable energy storage is mainly used for predicting load to reduce scheduling difficulty, minimizing transmission losses, and providing separate backup power for critical loads. Storage systems can respond to grid flexibility needs, enhancing grid stability and reliability.

On the microgrid side, renewable energy storage is primarily used for load management to maintain balance, smooth fluctuations to improve power quality, and balance control of microgrids. Storage systems ensure the stable operation of microgrids, improving power supply quality and reliability.

Renewable energy storage boasts diverse revenue models, primarily including capacity rental fees, ancillary service revenues, and spot market revenues.

Capacity rental fees are one of the most critical factors determining the economics of independent storage projects. Independent storage power stations can provide capacity rental to demand-side parties and charge corresponding fees. The fee standard is currently undetermined, roughly around 300 yuan/kW·year.

As independent market entities, new energy storage systems can participate in ancillary service markets to generate revenues. Common ancillary services include peak shaving and frequency regulation. Peak shaving often involves providing charging compensation based on peak shaving electricity volumes, with prices ranging from 0.15 yuan/kWh to 0.8 yuan/kWh. Frequency regulation typically involves compensation based on frequency regulation mileage, varying from 0.1 to 15 yuan/MW based on the AGC frequency regulation instructions responded to by units.

Upon entering the electricity spot market, storage power stations can formulate reasonable charging and discharging plans based on grid load forecasting curves and other data, settling according to spot market prices. When charging, they act as market users, purchasing electricity directly from the spot market; when discharging, they function as power generation enterprises, selling electricity directly in the spot market.

With the proliferation of renewable energy generation and the promotion of electricity policies, the value of energy storage is increasingly recognized, becoming an integral part of power systems. In the future, renewable energy storage will exhibit the following trends:

Research and application of new energy storage technologies will drive technological innovation in material science, electrochemistry, mechanical engineering, and other fields. These innovations will not only enhance the performance of storage technologies but also reduce costs, laying the foundation for their popularization and application.

The rapid development of energy storage technologies will drive the upgrading and transformation of related industrial chains. For instance, the development of the lithium-ion battery industry will propel rapid advancements in battery materials, manufacturing, and recycling, forming a complete industrial chain system.

Digitization and intelligence technologies will be widely applied in the monitoring, control, and optimization of energy storage systems. Through digitization, comprehensive perception, intelligent diagnosis, collaborative control, and smart operations and maintenance of energy storage systems can be achieved, enhancing their safety and efficiency.

With technological advancements and cost reductions, renewable energy storage will find application in more sectors and scenarios. For example, in the transportation sector, storage technologies can be used for rapid charging and range extension of electric vehicles. In the construction sector, they can be employed for energy management and optimization in smart home systems.

Governments worldwide will continue to introduce policies supporting the development of renewable energy storage, promoting research and commercialization of storage technologies. Meanwhile, with the reform and intensifying competition in electricity markets, energy storage technologies will become a crucial component of electricity markets, driving the transformation and upgrading of energy systems.

As a pivotal link in the renewable energy industry chain, renewable energy storage is of great significance in promoting energy transition and sustainable development. In the future, with technological innovation, industrial upgrading, digitization and intelligence development, as well as policy support and market driving forces, renewable energy storage will usher in broader development prospects. Through continuous research and exploration, we can anticipate renewable energy storage technologies to play an even more critical role in future energy systems.