Viewpoint | Maybe... the data center no longer needs to reduce PUE
In the past two years, all industries have been striving to promote the process of carbon neutrality. As a high energy carrying industry, the data center industry naturally has a duty to do. Both upstream and downstream enterprises in IDC industry pay special attention to the PUE value of data centers. IDC upstream and downstream enterprises have been "crossing the sea with eight immortals, showing their respective capabilities", trying to further reduce the PUE of the data center.
At present, there are three ways to calculate the PUE value of the data center: 1:=total energy consumption of the data center/IT equipment energy consumption, 2:=(IT equipment energy consumption+air conditioning energy consumption+power supply and distribution system energy consumption+other energy consumption)/IT equipment energy consumption, 3:=1+air conditioning energy consumption factor+power supply and distribution energy consumption factor+other energy consumption factors. Among them, "PUE value=total energy consumption of data center/energy consumption of IT equipment" is commonly used in the industry.
It can be seen from the calculation formula that even if the PUE of the data center is reduced further, the theoretical limit of the PUE value is also "1". At this stage, the new data centers PUE1.3 and 1.25 have become "routine operations". Some data centers apply liquid cooling. Under ideal conditions, PUE has broken through 1.1. It seems that the data center has seen a "ceiling" when it reduces the PUE value.
Renewable energy will become a must for data centers
From the perspective of the entire data center operation process, reducing PUE is only to reduce the overall carbon emissions of the data center in terms of equipment energy consumption. In the author's opinion, if the data center wants to achieve carbon neutrality, it should start from the "root", that is, from the energy supply side, to use renewable energy.
At this stage, most data centers still use mains power as the main source of power, and almost all of the mains power comes from "thermal power". If the data center can use renewable energy sources such as photovoltaic, hydropower, wind power and so on as power supply, it can achieve sustainable development from the root, thus promoting the process of carbon neutrality.
It is easy to see from the policy that China also intends to guide the data center to use renewable energy. The 14th Five Year Digital Economy Development Plan issued by the State Council clearly points out that we should continue to improve the utilization level of renewable energy in the data center.
The local government also actively responded to the national call by issuing relevant policy documents to promote the application of renewable energy in the data center. Shandong Provincial Department of Industry and Information Technology issued relevant documents stating that "the proportion of renewable energy used in the data center has increased by 10 percentage points to more than 25%"; Relevant documents issued by Ningxia Hui Autonomous Region pointed out that "by 2025, the renewable energy utilization rate in Ningxia hub area will reach 60%, and the renewable energy utilization rate in Zhongwei data center cluster will reach 65%."
It is easy to see from the policy and the development trend that renewable energy has become one of the mandatory options for future data centers.
Microgrid is the "escort" of data center power consumption
Although renewable energy is good, its unstable supply also makes many data center construction and operators "flinch". At present, the optimal solution of renewable energy is to configure "micro grid".
Microgrid, also known as "microgrid", refers to a network composed of multiple distributed generators and their related loads according to a certain topology, and connected to the conventional grid through static switches.
Micro grid is a micro power supply network that uses energy storage and control devices to realize the self balance of distributed generation and local load power and energy. It is the application of new technology in distribution network and a part of smart grid.
The micro grid is mainly composed of distributed generation, load, energy storage, power transformation and distribution and control systems. It can realize self control, protection and management of the autonomous power system. It can be connected to the external power grid (mains) or operated in isolation.
Microgrid is a concept relative to the traditional large grid. The development of microgrid can fully promote the large-scale access of distributed renewable energy. The micro grid and the large grid "complement each other", especially in areas not covered by the large grid, which can play a greater role to make up for the shortcomings of the large grid.
As mentioned above, the micro grid is a system that can be used to manage a variety of different energy sources (such as municipal power, photovoltaic, wind power, hydropower, and even diesel generators). The microgrid can help the data center to increase the proportion of renewable energy applications while ensuring safe and stable operation, and "escort" the application of renewable energy in the data center.
At the operation mode level, the micro grid is mainly divided into grid connected and isolated grid types. At this stage, the grid connected type is widely used and has strong applicability, that is, it can realize interaction with the traditional grid.
Compared with the traditional power grid, the main advantage of the micro grid is that it can digest and balance the distributed energy (such as wind power and hydropower) on the spot, and exchange energy with the traditional power grid at the same time (mainly used to "feed back" the power grid and realize "peak valley arbitrage").
According to the development trend of microgrid at this stage, microgrid mainly has the following characteristics.
Micro: Microgrid, as its name implies, is smaller than the "big grid". At present, the voltage level of microgrid is generally below 10kV; The system scale is generally at or below the megawatt level, which is relatively small compared with the traditional power grid. It is mainly conducive to local consumption of electric energy.
Sustainability: The distributed power supply in the micro grid is mainly composed of clean energy such as photovoltaic, hydropower and wind power, or it mixes clean energy power generation with municipal power and diesel generators, and runs a comprehensive energy management system. The use of microgrids can effectively help data centers reduce carbon emissions from the source.
Autonomy: The internal power quantity of the micro grid can achieve basic self balance, and the power exchange with the external grid generally does not exceed 20% of the total power quantity.
Reliable: As mentioned above, the microgrid deployed by the data center is generally deployed in the form of grid connection with the traditional grid. The microgrid and the municipal power supply "complement each other" and can be "mutually redundant". The microgrid supports the traditional power grid and can be switched smoothly in the grid connection and off grid modes, ensuring the stability of power consumption in the data center.
Driven by the "dual carbon" strategic goal, the large-scale application of renewable energy in the data center has become a general trend, and the existence of the micro grid can be seen as a "dispatcher", helping to balance energy storage, diesel generators, large grids, renewable energy power generation, and the power supply relationship between energy storage, helping the data center to increase the proportion of renewable energy applications, Further promote carbon neutrality in the data center.
To say the least, even if it is not to increase the proportion of renewable energy in the data center, the microgrid can help the data center to stabilize the power supply and relieve the power pressure. As we all know, "electricity" is the only source of energy for the data center. As the key infrastructure for converting watts into bits, the data center, under its own high requirements for business continuity and stability, naturally speaks for itself in terms of the stability and continuity of power supply.
According to statistics, more than one third of data center failures are caused by power supply, and the existence of microgrid can help the data center alleviate, or even eliminate, "concerns" on the power supply side. When the municipal power fails, the micro grid disconnected from the grid itself is an island. Renewable energy power provides continuous power to the data center. Since this kind of power is produced, stored and consumed independently of the power grid, its reliability and continuity are not affected by the power interruption of the traditional power grid.
Policy guidance+ Mature technology= Large scale application is coming
Micro grid development has been supported by mature technologies. At the present stage, the micro grid is mainly based on the power conversion and dispatching of distributed power generation, and adopts the off grid/grid connection mode to form a network. It is composed of several parts, including wind turbines, photovoltaic generators, batteries, diesel generators, municipal power networks, inverters, etc., which can form a complete self-contained power generation, distribution, and intelligent dispatching management system, with energy dispatching, grid protection Fast switching, real-time monitoring and other capabilities.
In recent years, with the development of technology, especially under the "blessing" of artificial intelligence, the microgrid has also applied machine learning, software/data drive and other technologies. Using the controller, it has realized the ability to quickly and automatically switch according to the actual situation. The advanced micro grid controller uses machine learning and data-driven solutions to track the real-time change of power grid price. When everything is normal, the power grid and microgrid will work together and provide power services to each other.
On the contrary, when the power price is low, the micro grid built by renewable energy power generation facilities and battery energy storage system will choose to connect power from the grid to charge the energy storage system;
In case of power grid failure or insufficient power supply (such as power outage due to peak power consumption and natural disasters), the data center can obtain more power from the micro grid to alleviate and balance the pressure on the grid. Even the micro grid can provide a considerable source of income for the data center through the demand side response (many local governments in China have issued policies to give the enterprises that have completed the demand side response a policy preference of recovering electricity at a high price).
The application of microgrid in various industries has been common. As early as 2018, Weidi Technology has innovatively launched a set of DC microgrid in the form of photovoltaic microgrid in Xiang'an New Campus of Xiamen University, which can directly supply power to data centers, DC charging piles, lighting, air conditioners and other electrical facilities by relying on solar energy; In September 2021 and September 2022, the Liaoning Federation of Industry and Commerce organized private enterprises to invest in the construction of two phases of the "wind and solar storage micro grid" project in Talma Township, Shenza County, Tibet, which highly integrated the three core technologies of wind hoods, pure square wave permanent magnet generators and controllers, built an intelligent micro grid, and solved the local power generation problems in high-altitude areas for many years
The microgrid has made outstanding contributions to ensuring power consumption. However, the application of microgrid in the data center is still in the development stage.
First, the application of microgrid in the data center needs further policy guidance. At present, some local governments have issued relevant policies to encourage and guide industries to apply microgrids to achieve carbon neutrality.
The Notice on Matters Related to Promoting the Healthy Development of the Photovoltaic Industry Chain issued by the General Office of the National Development and Reform Commission and the General Department of the National Energy Administration pointed out that the photovoltaic industry should be encouraged to increase green power consumption in the manufacturing process. Encourage polysilicon production enterprises to directly absorb green power such as photovoltaic, wind power and hydropower for production and manufacturing, and support the local absorption of green power through micro grid, source grid load storage, new energy self-contained power station and other forms. Shenzhen Municipal Development and Reform Commission of Guangdong Province printed and distributed the Shenzhen Municipal Measures for Promoting the High Quality Development of Green and Low Carbon Industries (Draft for Comments), which clearly pointed out that the demonstration construction of new energy micro grid should be promoted. Explore micro grid technology and operation management system suitable for urban photovoltaic and other new energy development, and encourage the use of renewable energy and energy storage facilities to build micro grids. The micro grid demonstration project consisting of distributed energy, energy storage devices and controllable loads will be subsidized by 20% of the total investment of the project, with a maximum of 5 million yuan. It is proposed in the Jing'an District Carbon Peak Implementation Plan issued by Shanghai Jing'an District to promote the construction of intelligent energy system. Build an internationally leading urban distribution network and explore a pilot diamond type distribution network. Explore the power demand response mechanism and promote the pilot construction of virtual power plants in the functional area of Nanjing West Road. Actively promote the integration of source grid load storage and charging and the development of multi energy complementation, promote the orderly charging of micro grid and electric vehicles with distributed "new energy+energy storage" as the main body, and actively explore the application of new energy storage technologies with low cost, high safety and long life
In the context of carbon neutrality, micro grid will be widely used in various industries. For high energy loaded data centers, the application of micro grid will become one of the feasible paths for data centers to achieve large-scale renewable energy applications, as well as smart and clean power grids, on the premise of ensuring business continuity and stability.
When the microgrid is applied in the data center on a large scale, the data center may no longer blindly rely on reducing PUE to promote the process of carbon neutrality in the industry.
