The average annual growth rate may reach 87.9%, and the flow battery is the sword of the long-term energy storage market, and the cost of electricity will be reduced to 0.2 yuan within three years

With the development of new energy, the industry's demand for energy storage is also gradually evolving. In the current field of electrochemical energy storage, lithium batteries are undoubtedly the protagonists. However, under the premise of broad prospects, other technical routes may also get a piece of the pie. It can be seen that in the past two years, the volume of flow batteries has gradually increased, the installed capacity has grown rapidly, and the news of the signing of projects of 100 MWh has come out one after another.

In the era of "one lithium dominance", why can flow batteries come to the forefront? Experts believe that hybrid energy storage is the future trend, and other technologies can be used as supplements. Weijing Energy Storage also told the "China Times" reporter that there will be more and more comprehensive distribution and storage scenarios such as lithium battery + liquid flow, and the safety, long-term and low price characteristics of flow batteries will also give it an advantage in the energy storage market of more than 2 hours.

It is worth noting that the theoretical advantages of flow batteries have not yet been proven in time and on a large scale. Taking the fastest growing all-vanadium flow battery in China as an example, the earliest completed energy storage project has been in continuous operation for 11 years, just over half of the service life of ordinary flow batteries. The initial investment cost is mostly 2.5-4 yuan/watt, and ultra-low cost has not yet been realized.

The flow battery walked to the front of the stage

Flow batteries have been unnoticeable in the past few years in the contrast of lithium halos, but this is changing.

Flow battery is an electrochemical energy storage technology proposed by American scientists in 1974, which also realizes charge and discharge through the redox reaction of ions on the electrode. Different from other energy storage batteries, the electrolyte solution of flow batteries is stored in a storage tank outside the battery, which can realize the separation of electrochemical reaction and energy storage site, making the battery power and energy storage capacity design relatively independent.

The main part of the battery system is the electrolyte and the stack (ion exchange membranes, electrodes, and other spare parts). According to the different types of positive and negative electrolyte solutions, flow batteries can be mainly divided into iron-chromium flow batteries, zinc-bromine flow batteries and all-vanadium flow batteries. Among many energy storage technologies, flow battery energy storage has the advantages of safety and reliability, high cost performance in the life cycle, environmental friendliness, and long cycle life.

The data show that in the start-up period from 1986 to 2000, the University of New South Wales in Australia applied for a patent for the all-vanadium flow battery for the first time, and the China Academy of Engineering Physics built a 500-watt and 1000-watt all-vanadium flow battery prototype, and the all-vanadium battery has gradually become the main research and development direction of flow batteries in various countries. Since 2001, all-vanadium flow batteries have entered the early stage of commercialization.

Weijing Energy Storage also told the "China Times" reporter that after 2008, Japan's technology flowed into China, setting off a wave of vanadium. Today, the fastest growing and most famous all-vanadium flow battery in mainland China is also the all-vanadium flow battery.

In the past two years, the number of domestic flow battery projects signed has increased significantly, and the scale has also shown a trend of increasing.

Recently, CNNC announced the purchase of 1 GWh of all-vanadium flow energy storage system; One month ago, also released 1 GWh of flow battery centralized procurement;In the same month, Dalian Rongke Energy Storage won the bid for the 100 MW/400 MWh all-vanadium flow energy storage power station project in Mayang County, Huaihua City, Hunan Province;At the 2023 CIIE, Weijing Energy Storage and Wenling City, Zhejiang Province agreed on the "Super G Factory" of zinc-iron flow batteries More than 300 robots in the factory can achieve an accuracy of ±0.1 millimeters in operations such as sucking up proton exchange membranes as thin as cicada wings.

According to the data, from 2018 to 2021, the cumulative installed capacity of global flow batteries continued to grow, rising from 79.5 MW to 152.2 MW. China's cumulative installed capacity of flow batteries rose from 16.1 MW to 51.6 MW. In 2021, the growth rate of China's flow battery installed capacity reached 125.3%, much higher than the growth rate of the global flow battery installed capacity in the same period, because China has gradually established a relatively complete flow battery industry chain, and a number of flow battery installation projects signed in the early stage were officially put into operation in 2021.

Yu Zhenhua, executive vice president of Zhongguancun Energy Storage Industry Technology Alliance, said that the current energy storage technology can be classified into four different echelons, the first echelon is pumped storage up to 1 gigawatt, and the second echelon is 100 megawatts, including lithium battery, compressed air, liquid flow, cold and heat storage, and the current pattern is liquid flow. The third echelon is at the level of 10 megawatts to 100 megawatts, and the current scale demonstration of flywheel and sodium-ion batteries has entered this category; the fourth echelon is still doing research and development demonstration of megawatt projects, including liquid metal, metal ion, and aqueous batteries.

Miao Changxing, a first-level inspector of the First Equipment Division of the Ministry of Industry and Information Technology, has publicly stated that the output value of the mainland's lithium-ion battery energy storage industry chain in 2022 will be close to 200 billion yuan, and in the first half of 2023, the installed capacity of new energy storage will reach 8.63 million kilowatts, which is equivalent to the total cumulative installed capacity of previous years.

In the current situation where lithium batteries occupy an absolute position, why can flow batteries still enter a period of rapid development and occupy a place in the market?

The sword is aimed at the long-term energy storage market

According to the report of the Toubao Research Institute, from 2018 to 2021, the historical market size of flow batteries will grow at an average annual compound growth rate of 55.2%, and the market size will reach 1.06 billion yuan in 2022, and it is expected to reach 24.89 billion yuan in 2027, with an average annual compound growth rate of 87.9% from 2022 to 2027.

The accelerated development of flow batteries is related to policy support. The National Energy Administration's "2022 Energy Work Guidance" proposes to ensure adequate power supply, and power generation will reach about 9.07 trillion kWh, a year-on-year increase of about 9.15%. In the case of maintaining this growth trend, the installed power generation capacity in 2030 should exceed 18 trillion kWh, of which about 9 trillion kWh will be generated from new energy sources, that is, new energy output will account for 50% of the total power generation.

At the same time, the demand for energy storage is also changing, such as the duration of energy storage that varies greatly.

Wang Xiaoli, general manager of Dalian Rongke Energy Storage, said that in the past, the implementation of projects had half an hour and 1 hour, and now the energy storage time requirement is 2 hours. In the northwest of the rapid development of new energy, the installed capacity of relatively high areas have been out of demand for 4 hours. It can be judged that with the further evolution of new energy, the realistic demand for long-term energy storage such as 6 hours, 8 hours, 10 hours, and even daily, weekly, and quarterly levels will appear.

Weijing Energy Storage said that at present, the common energy storage methods in the industry generally have shortcomings such as short energy storage time, poor safety and high LCOE, which is not conducive to supporting the application and promotion of new energy. Flow batteries have the characteristics of intrinsic safety, ultra-low cost, and long-term energy storage, and flow batteries have come to the gigawatt era and stand in front of the window of industrialization.

Therefore, the flow battery route is complementary to lithium battery technology. The reporter learned from Weijing Energy Storage that in the energy storage market within 2 hours, the technology of lithium batteries is mature and the cost is low. After 2 hours, the cost of lithium batteries gradually becomes higher, and they are not as cost-effective as flow batteries. The other party further revealed that the technical path of new energy storage does not have an absolute competitive relationship, but complements each other's advantages, and a national policy to encourage the development of long-term new energy storage will also be released.

In addition, hybrid energy storage has become an industry trend.

Yu Zhenhua, executive vice president of Zhongguancun Energy Storage Industry Technology Alliance, said that the current business model of energy storage is relatively simple, because this round still relies heavily on the policy of wind power and photovoltaic power to promote the development of energy storage. Next, as the application scenarios become more and more complex, the short-term and high-frequency caused by new energy, and the increasing demand for peak shaving and power consumption will derive a future with multiple scenarios, multiple technology routes, and different needs.

According to the Ministry of Industry and Information Technology's "2023 Energy Storage Equipment Industry Development Report", the largest scale of the current pilot demonstration application of flow batteries has reached 100 MW/400 MWh, built in Taierzhuang, Shandong, which is a demonstration of an electrochemical energy storage power station with a mixture of lithium-ion batteries and all-vanadium flow batteries, consisting of 29 sets of energy storage lithium iron phosphate battery systems and a set of all-vanadium flow battery energy storage systems. After the completion of this project, it can reduce power rationing by 60 million kWh per year, and carbon dioxide emissions can be reduced by 80,000 tons.

It is worth noting that in the face of the large-scale development of flow batteries, there is still an economic problem. Even if it has the characteristics of ultra-low cost in theory, the initial investment cost of flow batteries still needs to be reduced. The initial investment cost of all-vanadium flow battery energy storage is generally 2.5-4 yuan/watt, and the price of other slower-developing flow battery technologies will be higher.

Lin Boqiang, dean of the Energy Research Institute of Xiamen University, said that there will be people to try every technical route, and there will be people who want to kill it at a relatively low cost. If you look at the indicators such as safety, cost, and charging time, it should still be inferior to lithium batteries. But at the moment, it's going to be a scale effect, so it might reduce some costs. But in the end, the test is the cost performance, as well as its security.

At present, the investment threshold is an issue. To be large-scale and gain a foothold in the market, flow batteries must prove themselves over 10 years, or even longer, like lithium batteries. Security alone may not be enough, and the cost will have to be reduced. For example, how much the cost has fallen from the past to the present.

At the same time, the service life of flow batteries is usually 20 years, and there are no projects in China that have completed their life cycles. Taking Guodian Longyuan Woniushi all-vanadium flow battery energy storage power station as an example, this is the longest-running all-vanadium flow project in the world, which has been in operation for 11 consecutive years and has a life span of just over half.

Recently, Ge Qun, co-founder and chairman of Weijing Energy Storage, publicly stated that the LCOE of zinc-iron flow batteries will be reduced to 0.2 yuan within 3 years. Whether flow batteries can achieve safe, economical and green energy is not a triangle, and it may take time to answer.

Editor-in-charge: Zhang Zipeng Editor-in-chief: Zhang Yuning