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What is the difference between energy storage and data center?


Recently, the National Energy Administration held a regular press conference in Beijing. Liu Yafang, Deputy Director of the Energy Conservation and Scientific and Technological Equipment Department of the National Energy Administration, By the end of 2022, the installed capacity of new energy storage projects that have been put into operation nationwide has reached 8.7 million kilowatts, with an average energy storage duration of about 2.1 hours, an increase of more than 110% over the end of 2021.

The development of energy storage is booming, which will affect the power consumption of various industries, especially for data centers that rely on electricity for uninterrupted operation. In addition, the relationship between energy storage and data center energy conservation and carbon reduction is getting closer, How to develop energy storage has also become the focus of the data center.

(According to different forms of energy storage, generalized energy storage includes electric energy storage, thermal energy storage and hydrogen energy storage. Power supply in the data center is the basis for its normal operation. Therefore, in terms of energy storage, the industry focuses on electric energy storage, and the energy storage discussed in this paper also refers to electric energy storage.)

Why does the data center need energy storage

For the data center, at the current stage, the main purpose of changing the form of energy power supply is to stabilize power consumption, and to save energy and carbon, cut peak and fill valley. Energy storage can play a role in these aspects.

Stable power consumption The power consumption of the data center can be divided into emergency power supply and common power supply. In theory, energy storage can play a role in stabilizing power generation in both aspects. First, the energy storage can replace the diesel generator for emergency response. As the backup power supply of the data center, it can provide stable power supply when the mains power is cut off; Second, the energy storage can become the main power supply of the data center, and provide high security daily power supply for the data center through grid connection.

Energy saving and carbon reduction The data center needs to improve the utilization rate of new energy, but solar energy, wind energy and other commonly used new energy are greatly affected by natural factors, and the power supply is unstable, which does not meet the power demand of the data center. Energy storage can solve this problem, improve the stability of new energy power supply, and finally reduce carbon emissions by using new energy power supply. In other words, energy storage provides conditions for the reduction of carbon emissions in the data center by storing new energy.

Cut peak and fill valley The form of energy storage determines that it can selectively discharge at the peak of power consumption and store energy at the bottom of power consumption. It has a regulatory role and can participate in peak shaving, auxiliary frequency modulation and other behaviors in the power market, so that the data center can benefit from it.

Based on this, The ideal energy storage can provide stable new energy power supply for the data center in the form of storage, and can be used in applications or daily power supply to achieve the purpose of energy conservation and carbon reduction, peak shaving and valley filling.

It is worth mentioning that the combination of data center and energy storage has attracted the attention of all places, and many places have issued relevant policies to promote its development. For example, in October last year, the Shandong Provincial Department of Industry and Information Technology issued the "Several Measures on Deepening Reform and Innovation to Promote the High Quality Development of the Digital Economy", which proposed that the construction of "wind and solar energy storage+big data center" would be launched, and the proportion of renewable energy used in the data center would increase by 10 percentage points to more than 25%.

Also in October last year, the Shenzhen Development and Reform Commission issued a public notice soliciting opinions on "Shenzhen's Several Measures to Promote the High Quality Development of Green and Low Carbon Industries (Draft for Comments)". The document pointed out that energy storage facilities should be arranged according to local conditions. Encourage data centers, 5G base stations, charging facilities, industrial parks, etc. to layout energy storage systems in combination with power grid demand. For electrochemical energy storage projects that have been connected to the grid and put into operation with an installed capacity of more than 1 megawatt, support will be given up to 0.2 yuan/kilowatt hour according to the actual discharge capacity. Each project will be supported for 3 years, and the total amount of funding will be up to 3 million yuan.

 Some data centers and energy storage combined development policies

Figure: Some data centers and energy storage combined development policies

It can be seen that the combined development of data center and energy storage has both policy support and industry demand, and has the prerequisite for further development.

What challenges does energy storage face

It is a general trend to fully integrate the development of data center and energy storage. However, from the current situation, energy storage is still in a relatively early stage, and there is still a certain gap with the ideal state of applications. The main reasons are as follows.

1. Huge energy storage demand

The data center is a high energy consumption industry, and its operation needs a huge amount of power. Taking the Class A data center with 1000 cabinets and 2.5 kW h single cabinet as an example, its power consumption during operation can reach 2500 kW h. The load required for the standby power supply is far more than that. According to the Code for Design of Data Centers (GB 50174-2017), the fuel storage capacity of diesel generators in the A-level data center should meet the requirements of 12h oil consumption, that is, if you want to replace diesel generators with energy storage, and become the standby power supply of this data center, you need at least 30000 kW h (i.e. 30WM h) of energy storage. If you want to use it as a common power source, you need more power.

As far as the data center itself is concerned, it is challenging to store such huge new energy energy at the current stage.

First of all, it is difficult for the data center to obtain such a level of power through new energy. For example, although distributed PV is widely used in the data center and its technology is relatively mature, its power generation has an upper limit, and further breakthroughs are needed to support the operation of the data center; Another example is hydrogen energy. Although its energy supply is more efficient, it is difficult to use and has high technical requirements. Its application in the data center is still in the experimental stage, which does not meet the conditions for large-scale promotion.

Secondly, in terms of energy storage capacity, the power demand of the backup power supply of the data center has reached the megawatt level (MW). Considering the redundant configuration, the demand for capacity may be higher in practice. However, the storage capacity in the data center is relatively low. Taking the widely used electrochemical energy storage as an example, the capacity of most of its products can only be used for UPS. According to the GB 50174-2017 Code for Design of Data Center, in the A-level data center, when diesel generator is used as the standby power supply, the minimum standby time of UPS system battery is 15 min, and the number of cabinets is still 1000, For example, the A-level data center with a single cabinet of 2.5 kW h has a storage capacity of about 625 kW h, which is far below the capacity requirement of the megawatt level.

Thirdly, in terms of construction Energy storage equipment is part of the power supply and distribution of the data center, and occupies a large space, Its construction will inevitably affect the planning and layout of the entire data center At the same time, the process of grid connection is complex, involving the coordination and compatibility of multiple different systems.

In addition, in terms of cost, although peak shaving and valley filling can be carried out theoretically, the input cost is also high, which includes both procurement and construction costs, as well as the operation and maintenance costs of the energy storage system. The operation cycle of the data center can be as long as 20-30 years. Adding or improving the energy storage system requires long-term management, and even requires training professional technicians for operation and maintenance, which not only increases the difficulty of operation and maintenance, but also increases the cost of operation and maintenance.

2. Application security issues

The data center needs green and low-carbon development, and more importantly, it needs to be safe and stable. This requires that the technology used in all links must be mature, and there must be a variety of solutions for related hidden dangers. However, energy storage currently has certain security risks.

Take the lithium battery, which has been widely used at present, for example, because of its small size, light weight and long service life, the industry is generally optimistic about its prospects, but even so, its application process is not as expected, an important reason is the possible safety problems. It can even be said that in recent years, lithium battery safety accidents have occurred frequently.

Taking electric vehicles as an example, the news of fire and explosion caused by lithium battery failure is not uncommon, and lithium batteries have been labeled as unsafe. In addition, the application of lithium batteries in the data center also needs a supporting battery management system. It is difficult to prevent thermal runaway through long-term practice, which also causes doubts about the application of lithium batteries. In contrast, lead-acid batteries are more stable in terms of safety performance, and the application scheme is simpler, which leads to the data center still preferring lead-acid batteries.

At the same time, the construction of the energy storage system is not only a lithium battery, but also involves the construction of related energy storage equipment, the exploration of hydrogen energy, the output of sufficient energy, and the construction of the micro grid, all of which need more complete security solutions. Without security, energy storage has no application foundation in the data center.

Feasibility exploration direction of energy storage development

The data center is a new infrastructure closely related to digitalization. Security and stability are the basic requirements. At the same time, in the market environment, the construction, operation and maintenance of the data center also need to meet the enterprise benefits. Energy storage, as a necessary part of energy conservation and carbon reduction in the data center, also needs to meet these conditions in the development process. At the same time, it needs to develop in combination with the existing characteristics and shortcomings of energy storage, that is, energy storage needs to stabilize the supply of new energy, and reduce the cost of energy storage on the basis of security, improve storage capacity, and enhance the power supply capacity of energy storage.

According to the existing practice and exploration, there are two development directions to meet the above conditions: one is to further improve the energy storage capacity of the data center; First, the data center improves the stability and security of new energy utilization through multi station integration mode with power stations, energy storage stations, etc.

Enhance the energy storage capacity of the data center At present, the breakthrough in energy storage capacity is of practical significance. For example, the "SPEAR" innovation demonstration project cooperated by 21Vianet and Tsinghua University Energy Internet Innovation Institute has an energy storage capacity of 2MWh and an output power of 1MW; The fuel cell project launched by Microsoft in June last year has an operating power of 3MW, which can meet the backup power demand of some data centers.

This shows that through the development of technology, the energy storage capacity of the data center can achieve quality improvement, which is possible to replace diesel. However, the related projects also have an obvious experimental nature. If you want to promote and apply them, you need to further enhance the security and stability, and the cost should also meet the market needs.

Multi station integration It has the characteristics of resource intensive, system integration and functional complementarity. Through this, the data center can effectively solve its own "short board" problems, such as the power station and large energy storage station, which can ensure the sufficiency, security and stability of new energy. After the data center is fully integrated with it, it can solve its difficulties in large-scale new energy acquisition and storage capacity, Meet the requirements of the data center for new energy power supply, and finally achieve the multiple goals of green power production, stabilizing peak and valley, and reducing emissions.

It is worth noting that in the process of multi station integration, the application of artificial intelligence and big data analysis are extremely important. This is because multi station integration involves the coordination of multiple systems. When peak shaving and valley filling are carried out, it must also have a high capacity of energy storage resource scheduling and prediction and aggregation, both of which need the support of artificial intelligence and data analysis.

At present, there are many practices in multi region and multi station integration. For example, the world's first 100 MW advanced compressed air energy storage national demonstration project completed in December 2021, with a construction scale of 100 MW/400 MWh, can cooperate with wind power, photovoltaic, regional power grid, cloud computing center and other joint operations, and can better meet the power demand of the data center.

The project of Shanxi Tianzhen Source Grid Load Sharing Energy Storage Power Station, which launched EPC bidding last June, aims to solve the problems of volatility, randomness and intermittency of the new energy power generation direct supply data center, improve the proportion of green power used in the data center, and promote the low-carbon development of big data industry.

More energy storage station projects are also under planning and construction. According to incomplete statistics from the media, in December last year alone, about 28 new energy storage projects were completed and delivered, including multiple independent shared energy storage stations with 100 MW capacity. Relevant policies are also increasing. According to data, since 2021, Shandong, Hunan, Zhejiang, Inner Mongolia and other provinces have successively issued guidance on energy storage construction, encouraged investment in the construction of shared (independent) energy storage power stations, and adopted a policy oriented approach to encourage supporting construction or sharing mode to implement new energy power generation projects with new energy storage, It has laid a foundation for the data center to conduct multi station integration.

In addition, there are more and more discussions on energy storage, such as the one held at the National Convention Center in Beijing on February 27-28, 2023 The 17th annual ceremony of China's IDC industry Medium( Click the link to learn more: Several guests will discuss the utilization of energy, optical storage DC power supply system, etc Share and discuss, Through communication, it is conducive to the development of energy storage technology and can promote the application of energy storage in the data center. The registration channel has been opened, Open link: , click to register for the conference , you can register

On the whole, energy storage can promote the stability of power supply in the data center, and help the data center achieve energy conservation and carbon reduction, peak shaving and valley filling. In order to achieve ideal energy storage, it requires stable and continuous supply of new energy, sufficient energy storage capacity, lower cost, and more secure power supply. Through the exchange and learning of related technologies, the data center will explore storage capacity, multi station integration, and related technologies. Under the joint promotion of policy and industry demand, it is believed that energy storage will usher in further development.