It is understood that hybrid energy storage systems use a combination of two or more energy storage technologies with different performance characteristics to improve the overall performance of the system. In the eyes of industry insiders, this model can not only compensate for the shortcomings of a single energy storage technology and improve system efficiency, but also promote the development of various emerging battery technologies, with broad prospects.

Advantages of hybrid energy storage systems

The hybrid energy storage system combines multiple energy storage technologies, such as batteries and supercapacitors, each with its own advantages and disadvantages. Through intelligent management, different energy storage methods can be flexibly allocated according to actual needs, thereby improving energy utilization efficiency.

Enhancing grid stability: In the grid, hybrid energy storage systems can quickly respond to changes in electricity demand, helping to maintain voltage and frequency stability of the grid. This rapid response capability helps to enhance the stability and reliability of the power grid.

Extend the lifespan of energy storage devices: Different energy storage components can complement each other, reducing the burden of a single energy storage method. And when continuous power supply is needed, the battery can provide stable power output. This complementary usage method can effectively extend the overall service life of energy storage devices.

Optimizing energy costs: By using a hybrid energy storage system, it is possible to better utilize the differences in electricity prices during different time periods for peak valley arbitrage and reduce energy costs. Meanwhile, hybrid energy storage systems can also reduce energy waste and improve the economic efficiency of energy use.

Enhance the flexibility of energy utilization: Hybrid energy storage systems can be customized and optimized according to actual needs to meet energy demands in different scenarios. Whether it is household electricity, commercial electricity, or industrial electricity, hybrid energy storage systems can achieve more flexible and efficient energy management.

High risk diversification and overall efficiency: The hybrid energy storage system disperses overall risks and improves overall efficiency through the complementarity of multiple technological routes. For example, the combination of lithium-ion batteries and flow batteries for energy storage can provide backup power, frequency regulation, peak shaving, and other functions.

Accelerate project construction

In recent years, China's energy storage industry has developed rapidly, with new energy storage technologies such as lithium-ion batteries and flow batteries emerging like mushrooms after rain. With the continuous expansion of application scenarios and the refinement of system requirements, a single type of energy storage is no longer sufficient to meet market demand. In this context, hybrid energy storage has emerged.

It is understood that hybrid energy storage can achieve the effect of "1+1>2" through its advantages of strong complementary performance, multiple functions, risk diversification, and high comprehensive efficiency, thus attracting attention from the industry. In 2022, the National Development and Reform Commission and the National Energy Administration issued the "Implementation Plan for the Development of New Energy Storage in the 14th Five Year Plan", which mentioned promoting the joint application of various energy storage technologies and conducting pilot demonstrations of composite energy storage based on system demand.

Under policy guidance, the construction of hybrid energy storage projects continues to accelerate, with multiple projects being connected to the grid and put into operation. In terms of project demonstration, the National Energy Administration released the "List of New Energy Storage Pilot Demonstration Projects" at the beginning of this year, with a total of 56 projects selected, including 7 mixed energy storage projects including 795MW/1600MWh in Lijin County, Shandong Province, 100MW/200MWh in Pinglu District, Shuozhou City, Shanxi Province, and 256.5MW/1000MWh in Yizhou District, Hami City, Xinjiang Uygur Autonomous Region. The large number of selected hybrid energy storage projects has become a major highlight of this new energy storage pilot demonstration.

In June, the China Electric Power Construction Xinjiang Barkol 156MW/624MWh energy storage project, designed, constructed, and equipped by CRRC Zhuzhou, a subsidiary of CRRC Group, was officially put into operation. The project is equipped with a 150MW/600MWh lithium iron phosphate battery compartment, a 2.5MW/10MWh semi-solid battery energy storage system, a 2.5MW/10MWh vanadium flow energy storage system, and a 1MW/4MWh sodium ion battery energy storage system, forming a diversified energy storage system.

In October, the 400MW/1600MWh hybrid electrochemical shared energy storage project in Ganquanbao Economic and Technological Development Zone, Urumqi, Xinjiang was launched. The shared energy storage project adopts electrochemical energy storage form, and various mixed technology routes such as lithium iron phosphate, advanced sodium ions, and all vanadium liquid flow.

The industrial chain needs to be improved

Overall, there are various forms of hybrid energy storage, mainly "lithium iron phosphate+", including "lithium iron phosphate+flow batteries" and so on. Industry analysis believes that currently, China's electrochemical energy storage is mainly based on lithium iron phosphate batteries, and hybrid energy storage can solve the shortcomings of a single lithium iron phosphate technology route. Moreover, in the event of a malfunction or failure of a certain energy storage technology, other technologies can still continue to provide energy storage and release.

However, despite the advantages of hybrid energy storage and the progress made in project construction, there are still challenges in achieving wider commercial applications.

Due to the fact that each technology in a hybrid energy storage system has its own working principle and operating characteristics, a professional technical support team is needed to ensure the stable operation and high performance of the hybrid energy storage system, "said an energy storage industry analyst.

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Drive emerging technologies

In the eyes of industry insiders, future energy storage applications will develop towards multi scenario, multi technology routes, and diversified directions. The comprehensive optimization of energy storage cost and performance will be the key direction of current and future power system energy storage layout. By mixing energy storage and fully utilizing the advantages of different energy storage technologies, more efficient and flexible energy storage and management will be achieved.

The application of lithium battery hybrid with other technological routes has emerged one after another, and various new energy storage technologies complement each other to meet the demands of diverse scenarios. In the long run, with the diversification of energy storage application scenarios and the maturity of various new energy storage technologies, hybrid energy storage combination applications will become the development direction under the comprehensive consideration of economy and applicability.

Since the beginning of this year, numerous hybrid energy storage projects have entered the grid connection period. Industry analysts believe that as more and more hybrid energy storage projects move towards practical operational verification, hybrid energy storage will experience a leapfrog growth and is expected to achieve wider commercial applications in specific market sectors in the coming years.

The commercialization process of hybrid energy storage mainly depends on technological progress and market demand. In the short term, the balance demand of the power system will still be dominated by flexible resources for short-term regulation. With the increasing proportion of new energy in the power generation structure, the demand for long-term energy storage will continue to increase, and hybrid energy storage is expected to usher in a period of development opportunities, "Wu Wei pointed out.

In addition, there are also opinions in the industry that the development of hybrid energy storage will bring more application space and market opportunities for various new battery technologies. Some new types of energy storage, such as flow batteries and flywheel energy storage, have high costs and are still small in scale. However, with the application of hybrid energy storage, they can accelerate the penetration and layout.