Although new energy storage has developed by leaps and bounds, the low utilization rate of new energy distribution and storage is a pain in the industry.
By the end of 2023, the grid-connected capacity of new energy storage in mainland China will reach 31.39 million kW/66.87 million kWh, with an average energy storage time of 2.1 hours, and 22.6 million kW of new energy storage capacity throughout the year, which is 10 times that of the end of the 13th Five-Year Plan and 3 times the new scale in 2022.
While the new energy storage has made historic achievements, the problem of "construction but not adjustment" of new energy compulsory distribution and storage has become the "other side of the coin".
As Liu Yafang, former deputy director of the Science and Technology Department of the National Energy Administration, said at the 14th China International Energy Storage Conference in March this year, the grid-connected and dispatching operation of new energy storage needs to be improved and strengthened.
Liu Yafang's "construction but not adjustment" problem is mainly the problem caused by the compulsory distribution and storage of new energy. New energy distribution and storage is "one charge and one discharge" at most a day, and many projects only part of the energy storage unit is called, or even basically not called to become a furnishing.
Coincidentally. On April 10, at the 12th Energy Storage International Summit, Shu Yinbiao, an academician of the Chinese Academy of Engineering, also mentioned the low utilization rate of new energy storage in his keynote speech. Shu Yinbiao also disclosed that the average utilization rate of user-side, power grid measurement, and new energy compulsory distribution and storage projects was only 65%, 38%, and 17% respectively.
It can be seen that the utilization rate of compulsory distribution and storage is the lowest, and the problem is very serious (the full text of Shu Yinbiao's speech can be viewed).
So, why is the utilization rate of new energy distribution and storage, which accounts for nearly 5% of the country's new energy storage installed capacity, so low? What are the "bottlenecks" behind the "construction but not adjustment" to be solved?
The pain of "building but not adjusting".
Many people believe that the utilization rate of new energy distribution and storage is too low or even "built but not adjusted", because power grid companies prefer to call grid-side energy storage power stations. The data also confirms that the utilization rate of 38% of grid-side energy storage is indeed higher than the utilization rate of 17% of new energy distribution and storage.
However, this attribution is an oversimplification. The utilization rate of new energy distribution and storage is too low, and there are still institutional reasons.
First, the local new energy distribution and storage policies only stipulate the basic parameters such as the proportion of energy storage allocation, but do not introduce specific use and assessment methods, such as how energy storage participates in scheduling, the frequency of scheduling, the number of charging and discharging, the depth of discharge, etc., which to a certain extent leads to the fact that strong energy storage is rarely called.
Second, at present, the grid dispatching has not yet formed a complete system for energy storage information upload, so it cannot be combined with the existing AGC (automatic generation control) power delivery system. This leads to the inconsistency between the output of the energy storage system during charging and the output issued by the AGC, resulting in the problem that the power station is assessed because the output curve cannot be tracked while contributing to the peak shaving and valley filling of the system.
Third, in some areas, because the power grid will not give the optical storage system a command discharge at night, the electricity stored by energy storage in the irradiation stage cannot be used to support the evening peak electricity consumption, and can only be used in the afternoon when the irradiation is poor, affecting the peak-to-valley power generation price difference of energy storage.
If the above problems are attributed to external causes, the more important internal causes are the problems of the lithium battery energy storage route itself. External causes ultimately work through internal causes.
Lithium battery energy storage is used in electric vehicles, and there is no problem with it for industrial and commercial distribution and storage, but there is a problem with large-scale energy storage. Taking Qinghai as an example, 500,000 kilowatts of installed energy storage needs to be adjusted for 20 million kilowatts of photovoltaic and nearly 10 million kilowatts of wind power. The capacity of new energy distribution and storage to regulate such a large-scale centralized power station is far from sufficient.
Zheng Yaodong, a full-time member of the expert committee of China Southern Power Grid, has publicly disclosed a set of data: the cumulative discharge of electrochemical energy storage in Xinjiang in 2022 will only account for 0.0047% of the total cumulative power generation of new energy in the region. The data shows that energy storage is far from enough to support the consumption of new energy.
Why is the new energy storage so unsatisfactory?
Huaxia Energy Network noted that at the 12th Energy Storage International Summit, Zhang Guanghui, Deputy General Manager of Huawei Digital Power China, and Xu Jinmei, CTO of CATL ESS, both pointed out that this problem is mainly limited by the performance of energy storage lithium batteries that do not meet the requirements, mainly due to low energy density, insufficient effective capacity, insufficient peak regulation capacity, insufficient charging and discharging, overcharging and overdischarging, short life of energy storage cells (5 to 7 years), and rapid energy storage attenuation.
In other words, from the perspective of charging and discharging capacity, the operational reliability of lithium battery energy storage cannot stand the test and cannot meet the needs of the power system. This is also the main reason for the low utilization rate of new energy distribution and storage in the power grid.
A large number of power electronic equipment is connected to the power grid, which also poses a great challenge to the safe operation of the power grid.
"Bad money drives out good money"
The performance of the energy storage battery is not up to standard, of course, it needs to be upgraded. However, unfortunately, under the policy of compulsory distribution and storage industry, the energy storage industry is staging a drama of "bad money driving out good money".
At the 12th Energy Storage International Summit, Zhang Jianhui, chairman and general manager of Hipostron, said bluntly in his speech: "Let's take a look at the energy storage exhibition, whether it is energy storage cells or energy storage system integration, it is highly homogeneous. Basically, after visiting one exhibition hall, you don't need to visit other exhibition halls. ”
In Zhang Jianhui's view, the problem of homogenization itself can be solved. "For energy storage manufacturers, if the effective capacity is insufficient, it is necessary to increase the effective capacity, and the attenuation is fast to reduce the attenuation, what kind of energy storage is needed for wind power, what kind of energy storage is needed for photovoltaics, what kind of energy storage is needed for new energy distribution and storage, and what kind of energy storage is easier to be dispatched by the power grid, which can be differentiated. ”
However, under the policy of mandatory distribution and storage, among the more than 60,000 large and small energy storage companies in China, few companies can dive into technology research and development and upgrade products for a long time.
In the past two years, a large number of companies have swarmed in the primary market for rapid financing, and then with the help of capital savagery, they have continued to use expansion and price reduction to seize the market, and the energy storage battery has been "rolled" from 1.5 yuan/Wh to about 0.5 yuan/Wh in more than a year. The calculation of these energy storage companies is to quickly do large-scale and occupy the market, and then realize the "blood" of capital in the IPO feast.
This "strange status quo" has led to worrying product quality for energy storage. Even in September last year, a well-known energy storage company that is highly sought after by capital fell into a product quality turmoil, and it was reported on the Internet that its 4.5 GW energy storage cells were returned by the owner, "returning the goods from eight warehouses, worth 2 billion yuan".
According to incomplete statistics, since 2018, there have been more than 40 explosions and fires of energy storage batteries around the world, exposing serious problems such as insufficient safety and reliability and inadequate safety management measures in energy storage battery products.
The root cause of the safety problem of energy storage is that "bad money drives out good money". The price is rolled to the extreme, cutting corners is inevitable, and the truth of "you get what you pay for" is understood.
Not only at the manufacturing end of energy storage cells, but also on the owners of energy storage power stations.
"One of our PV projects in the northwest has been equipped with energy storage power stations according to local requirements, and we are just trying to connect them to the grid smoothly. According to the executives of a new energy company under a central power enterprise, this is equivalent to the configuration of energy storage has become a "road" for grid-connected power generation of new energy projects, "new energy enterprises configure energy storage, often choose to drag it on", "the low price of energy storage batteries is common, and the phenomenon of shoddy is common", "anyway, you don't need to build it, just buy the cheapest product", such practices abound.
In order to seize resources, the construction unit is more concerned about whether the project can pass the grid-connected acceptance, and the application effect of energy storage is secondary. So, who is responsible for the operation effect and revenue of the distribution and storage system for 10~15 years?
The foundation for the healthy development of the energy storage industry is that all manufacturers spend their minds on increasing R&D efforts, technology climbing, and continuously improving the performance of energy storage products. However, in the current environment of distorted incentives and "bad money driving out good money", it is not easy for energy storage to return to the path of benign development.
Energy storage should be repositioned
If new energy distribution and storage wants to gradually improve the utilization rate, it is not completely without a path to follow, which must first clearly position the function of new energy distribution and storage.
The policy of compulsory distribution and storage of new energy can be traced back to 2017, which first began in Qinghai. At that time, Qinghai required wind power projects to be developed in the planning year to be equipped with energy storage at a rate of 10%. Subsequently, this policy was implemented in various places. At that time, when the proportion of new energy was very low, the effect of new energy distribution and storage was acceptable.
But now, the installed capacity of new energy has exceeded 1 billion kilowatts, and energy storage is a bit powerless to regulate such a large scale of new energy (see Huaxia Energy Network's previous report).
So, what is the value of energy storage? As a "power bank" for wind power and photovoltaics, collecting and releasing abandoned wind and solar power and releasing them at peak electricity consumption is the most common expectation of new energy distribution and storage.
However, as recognized by many battery cell R&D enterprises, lithium battery energy storage is still in the initial stage of technology climbing, and it cannot be a "power bank" for such large-scale wind power and photovoltaics. At present, it is more reliable to do frequency modulation.
The average operation of the power station after one year of operation (source: the 2nd New Energy Power Development Forum)
According to the data of industry experts, the current utilization rate of user-side energy storage is 65%, which is higher than the utilization rate of user-side energy storage, which is the energy storage equipped with thermal power plants (see the figure above). The positioning of thermal power distribution and storage is not to act as a "power bank", but to modulate the frequency of thermal power.
The first is to play its function of supporting the frequency of the power system, and then after the energy storage technology is becoming more and more mature, it will gradually realize the "charging treasure" function of new energy distribution and storage.
Whether it is stabilizing the power grid, improving the resilience of the system, or the long-term wind and solar new energy "power bank", in order to truly play the role of new energy distribution and storage, there must be a supporting electricity price mechanism behind it.
In his keynote speech at the 12th Energy Storage International Summit, Academician Shu Yinbiao suggested that the rules and standards for the operation of new energy storage dispatching should be formulated, and the operation mechanism of new energy storage to participate in the power market should be improved, the construction of the spot market should be accelerated, and the relevant rules for the participation of new energy storage power stations in the electric energy market and ancillary service market should be improved, and the peak-to-valley price difference should be moderately widened, so that new energy distribution and storage can earn a reasonable electricity price difference.
Only with a reasonable electricity price mechanism, electrochemical energy storage power stations can be economical, and the industry can develop benignly.
Industrial and commercial photovoltaic distribution and storage is the most calculated. Taking Zhejiang as an example, the peak-to-valley price difference of electricity prices in Zhejiang has reached 0.95 yuan, and industrial and commercial photovoltaic distribution and storage can be charged and discharged twice to earn reasonable income. Compared with Zhejiang's two charging and discharging, the current new energy distribution and storage can only be one charge and one discharge, and the electricity price of centralized new energy participating in the power market is basically locked at about 0.3 yuan/kWh, and the space for new energy distribution and storage to earn the peak-to-valley price difference is extremely limited.
Academician Shu Yinbiao also suggested that for the high-quality development of energy storage, it is necessary to organize power grid enterprises to predict and release the demand for new energy storage construction in a timely manner, and guide the investment and construction of various entities by market-oriented means. A reasonable electricity price mechanism is the basic guarantee for the healthy development of new energy storage.
Article source: Electrochemical energy storage