Source: Fresh Dates Classroom (xzclasscom)
Author: Xiao Zaojun
Internet of Things Think Tank reprinted
Guide
In recent years, with the large-scale construction of 5G and data centers, operators have not only invested a lot of construction funds, but also spent a lot of money on energy consumption costs, forming a heavy cost burden.
The energy consumption of communication networks has always been the focus of people's attention.
According to operator financial report data, in 2020, China Mobile's energy consumption costs are 37.66 billion yuan, China Telecom 14.64 billion yuan, and China Unicom 12.9 billion yuan. The three major telecom operators together are 65.2 billion yuan. It should be known that the profits of the three major operators in 2020 are a total of 141.148 billion yuan.
Energy consumption costs of the three major telecom operators (unit: 100 million yuan)
In recent years, with the large-scale construction of 5G and data centers, operators have not only invested a lot of construction funds, but also spent a lot of money on energy consumption costs, forming a heavy cost burden.
From the following figure, we can also see that the energy consumption expenditure of operators in 2020 has directly soared by more than 6 billion yuan compared with the previous year, with an amazing growth rate.
The increasing energy consumption of communication networks means not only huge electricity bills, but also massive carbon emissions.
According to the estimates of the Ministry of Industry and Information Technology, according to the current development trend, the total carbon emissions of 5G and data centers in China will reach 230 million to 310 million tons in 2035, accounting for about 2 to 4% of China's total carbon emissions, which is equivalent to twice the current carbon dioxide emissions of Beijing.
As we all know, our country has clearly put forward the "double carbon" strategy in 2020, that is, to achieve "carbon peak" in 2030 and "carbon neutrality" in 2060. The energy consumption of communication networks has seriously hindered the realization of the "double carbon" strategic goal. It is not only related to the operating performance of operators, but also affects our ecological environment and the sustainable development of the country's social economy.
So, how to solve the problem of energy consumption of communication networks? How can we save energy and reduce emissions? 5G, data center these "electric tigers", is there really a way to tame?
The evolution of the idea of energy conservation and emission reduction
There is, of course, a way to do it.
In fact, the energy saving and emission reduction of communication networks has been studied by the industry for many years, and some experiences and methods have also been accumulated and precipitated.
With the rapid development of the times, the scale of communication networks has become larger and larger, and the energy consumption has become larger and larger.
Therefore, on the basis of traditional empirical methods, the communication industry has put forward a more macroscopic and scientific communication network energy conservation and emission reduction ideas, which can be summarized into two words, namely: the whole life cycle of the network and the end-to-end.
The so-called network life cycle energy conservation and emission reduction refers to the overall planning from the macro level when designing and planning energy conservation and emission reduction programs, covering all aspects of communication equipment from research and development, production, construction to maintenance, and comprehensively improving efficiency and energy reduction.
End-to-end, from the perspective of products and equipment types, energy conservation and emission reduction are implemented in various fields of communication networks such as terminals, access networks (base stations), bearer networks, core networks, and data centers.
The new energy conservation and emission reduction ideas emphasize the overall thinking, as well as multi-dimensional collaboration, which has brought about a significant improvement in energy conservation efficiency, and has gradually been accepted by more and more operators and equipment manufacturers, becoming an industry trend.
Specific measures for energy conservation and emission reduction
Next, we will introduce the energy-saving measures of communication networks one by one according to the perspective of the whole life cycle of the network.
Let's take a look at the product development and design process.
Equipment power consumption control and improvement in the product development and design stage is equivalent to energy saving and emission reduction from the source.
This is the most direct way to achieve the effect, but also the most difficult way, the company's research and development capabilities are very demanding. Enterprises need to invest a lot of resources to innovate and trial and error, and there is less and less room for improvement.
Take 5G base stations as an example. The energy consumption of 5G base stations has always been the focus of people's attention. Due to the introduction of AAU active antenna and Massive MIMO technology, the energy consumption of 5G base stations has increased significantly compared with 4G. The power consumption of a single station of 5G is about 2.5 to 3.5 times that of 4G. (Of course, we also need to note that the energy consumption per bit of 5G is significantly reduced.) That is to say, the energy efficiency of 5G is significantly higher than that of 4G. ）
4G/5G base station power consumption comparison in 2019
Source: "New Variables for New Infrastructure, Green Communications under "Double Carbon""
In order to reduce the working power consumption of 5G base stations, equipment manufacturers can be said to be racking their brains.
In the product design stage, manufacturers need to put energy consumption indicators in the same important position as performance indicators.
In order to meet the energy consumption requirements, they will achieve the ultimate energy efficiency of the product by using self-developed high-performance chips, more reasonable product structure design, and more advanced materials and processes.
Take an example from ZTE. ZTE is a core supplier of wireless system equipment worldwide, delivering hundreds of thousands of 5G base stations to customers every year. Therefore, they attach great importance to the energy consumption indicators of 5G base stations.
Through the self-developed high-integration, high-performance baseband processing, digital medium frequency processing chip, and the use of high-integration transceivers, they continuously optimize circuit design and DPD processing, effectively improve the efficiency of power amplifiers, and comprehensively reduce the energy consumption of 5G AAU equipment.
ZTE's base station products
5G power amplifier is the core device of the base station, ZTE uses GaN+ technology with hardware algorithm improvement, so that the power amplifier efficiency reaches more than 55%.
In terms of new processes and new materials, ZTE has improved its heat dissipation efficiency by 20% by optimizing AAU's thermal conductivity, reducing weight, and adopting innovative V-shaped bionic cooling teeth combined with new materials and ultra-light architecture.
Huawei released the E2 (Energy Efficiency) system for green 5G networks last year. In terms of access networks, Huawei believes that the evolution of 5G RF to ultra-large antenna arrays enables spatial beam concentration and improves energy transmission efficiency.
In addition, Huawei also proposed that the RF active part uses multi-channel technology to increase the capacity of the device, which can also greatly improve the bit energy efficiency of the device. In addition, through the use of efficient ultra-wideband power amplifiers and channel technology, the integration of multiple single-frequency devices into one ultra-broadband equipment can also greatly reduce the number and cost of equipment deployment and reduce equipment energy consumption.
Next, there is the production and manufacturing of the product.
How to reduce the energy consumption in the industrial manufacturing process is not only a problem in the communication industry, but also a common problem in the entire industrial community.
In the past, the energy-saving method mainly focused on the process upgrading of equipment and the transformation and replacement of energy.
Now, the energy saving space in this way is getting smaller and smaller. As a result, the introduction of 5G, industrial Internet, MEC, AI and other digital intelligent technologies to carry out intelligent manufacturing has become a new choice for industry.
Intelligent manufacturing workshop
Intelligent manufacturing has achieved a high degree of digitalization, intelligence and unmanned, which has greatly improved production efficiency and reduced carbon emissions in the production process.
Next, we will focus on the construction and operation and maintenance of communication networks. These two links are now the focus of energy conservation and emission reduction of the entire industry, and the development potential is great.
Let's look at the base station side first.
For operators, 70% of 5G's energy consumption comes from RAN (access network). Therefore, energy saving and consumption reduction on the site side is their top priority.
Energy model of base station site (from: GSMA, translated by: Fresh Jujube Classroom)
The energy saving of base stations usually includes the following ways: the improvement of site networking schemes, the use of clean energy, the introduction of AI technology, and so on.
The centralization, greening, and miniaturization of sites are the mainstream trends in these years. Especially after C-RAN was proposed, with the upgrading of technology, the networking deployment mode of the base station began to change significantly.
Mainstream equipment vendors, including ZTE and Huawei, have proposed a plan for a simplified site.
In the scheme, the construction mode of the base station changes from distributed to centralized, from geometric superposition to logical integration. For example, the equipment is miniaturized and integrated, and the machine room is turned into a cabinet and a cabinet into a pole station, so as to minimize the occupation of equipment space and reduce the number of computer rooms, thereby reducing the rental cost of the computer room and the cost of air conditioning.
In terms of energy, the main energy-saving measures of the base station are: the use of a large number of clean energy, the mains power to green electricity, reduce electricity bills, reduce carbon emissions.
Specific practices include:
First, try to use solar photovoltaic power supply to achieve solar energy, AC power, battery and other multi-channel power supply guarantee.
During the peak power consumption period during the day, it is powered by photovoltaic and energy storage battery equipment, and the energy storage battery uses the trough power consumption period at night to store energy to achieve the purpose of "peak shaving and valley filling".
Anhui Lu'an Mobile's 5G green base station
Second, the use of lithium batteries instead of lead-acid batteries.
Traditional lead-acid batteries face many problems, such as large size, heavy weight, short cycle life, and harsh environmental requirements, too high temperature will reduce life, too low will affect the performance.
In contrast, lithium batteries are not only small and lightweight, but also more environmentally friendly. The energy volume density and energy weight density of lithium batteries are 4-5 times that of lead-acid batteries, and the cycle life is 10-20 times higher.
Image credit: Edge Data Center Infrastructure for 5G White Paper
In the past, lithium batteries were mainly used for backup. Now, there are many intelligent energy storage system solutions around lithium batteries.
Intelligent energy storage system (Image source: Digital Energy Top Ten Trends White Paper)
Such systems adopt more accurate electrochemical models, introduce digital intelligent technology, improve the accuracy of energy storage management, and can achieve better coordination with the power grid. It can also carry out staggered peak power management for ladder electricity prices to maximize the efficiency of staggered peak operations.
In addition to network architecture and energy transformation, the most effective means of energy conservation and emission reduction of communication networks is "intelligent operation and maintenance".
That is to say, intelligent energy management tools are deployed to improve network operation and maintenance efficiency, reduce invalid on-site costs and site downtime risks, and reduce network maintenance costs through multi-level energy efficiency improvement, preventive maintenance, multi-dimensional operation management and other functions.
When it comes to intelligence, of course, it is inseparable from AI.
AI technology has developed very rapidly in recent years, and the introduction of AI by communication technology focuses on the operation and maintenance stage.
Based on AI and big data technology, intelligent algorithms can predict, dispatch and distribute communication services, which can achieve optimal energy consumption per bit under the premise of ensuring user experience.
The most effective means of energy saving base stations is shutdown.
A few years ago, there was a popular saying that operators would shut down 5G base stations during the low peak of the network to save electricity bills. This statement caused an uproar in society at that time.
In fact, frequent switching of the base station power supply has a great impact on the life of the equipment. At present, operators do not simply turn off the power supply of the entire equipment, but carry out multi-dimensional and multi-granular energy-saving shutdown based on accurate analysis and prediction of service load.
In other words, it is smarter to shut down - not to turn off the base station, you can turn off the carrier, turn off the antenna channel, and even turn off subframes and off symbols.
Subframe shutdown
Channel shutdown
Carrier shutdown
4G/5G common-mode base station collaborative shutdown
Take ZTE's PowerPilot smart power-saving scheme as an example. It can realize symbol-level, channel-level and carrier-level shutdown, and achieve multi-level power saving at the site level for differentiated coverage scenarios, time periods and base station loads.
It can also actively identify energy-saving scenarios through network traffic and configuration information analysis, match energy-saving functions in different dimensions, realize energy-saving "one station and one policy", accurately predict the trend of network traffic load, and further tap the energy-saving efficiency at the network level.
Huawei's PowerStar 2.0 solution is also an intelligent power-saving solution that adjusts the allocation of network resources such as spectrum and carrier in real time based on service changes.
It improves the energy-saving means in an all-round way in terms of the type of shutdown resources, the shutdown time and the operation and maintenance efficiency, and realizes the dual excellence of energy saving and network performance in multi-dimensional collaboration.
Energy saving and emission reduction in data centers
In addition to the base station, the energy saving and emission reduction of the data center, I will also briefly talk to you.
With the launch of the national strategy of "counting the east and counting the west", the data center has become the focus of the entire society. As the main carrier of computing power, it also faces severe energy consumption problems. According to the data, in 2020, the national data center consumed a total of 204.5 billion kWh of electricity, accounting for 2.7% of the total electricity consumption of the whole society, which is very amazing.
Image source: Research on China's Data Center Energy Consumption and Renewable Energy Use Potential
The energy-saving and emission-reduction solutions of data centers have a lot in common with base stations, such as the introduction of new energy sources and the adoption of AI operation and maintenance. However, because of the large-scale and large-scale characteristics of the data center itself, its energy-saving solution has many special places.
As I said before when I introduced "East Counting And Counting West", there is a special indicator for data centers called PUE (Power Usage Effectiveness). PUE = total data center energy consumption / IT equipment energy consumption, the closer this value is to 1, it means that the data center has less energy consumption of non-IT equipment, that is, the higher the energy efficiency level.
In addition to IT business equipment, the largest energy consumption expense of data centers is concentrated on cooling and cooling.
Therefore, the energy-saving thinking of data centers focuses on two aspects: first, the use of cleaner electric energy to increase the proportion of renewable energy; second, the use of new refrigeration technologies and methods to improve cooling efficiency.
The proportion of renewable energy, this is needless to say. The national policy is guiding the construction of data centers to develop in areas with more abundant wind, hydropower and solar energy, in order to make better use of new energy and reduce dependence on fossil energy.
In addition to external energy, the data center is also working hard to transform the internal energy storage system, using the "HVDC + mains" scheme to replace the traditional "UPS + mains" scheme.
HVDC is High Voltage Direct Current, HVDC Transmission. The reliability and safety of "HVDC + mains" are higher, and the power supply efficiency is stronger than that of "UPS + mains", which is the mainstream development trend of uninterruptible power supply.
Now many data center service providers focus on creating flexible energy-using power modules, integrating and intelligently mobilizing equipment for the scene of power consumption, power backup, and energy storage, and forming a local router for the data center energy network. To put it bluntly, it is from a single mains power to a multi-energy complementary, any electricity can be used, flexible adaptation.
It is worth mentioning that DC is now becoming the choice for more data centers. Because the loss of DC is smaller, the utilization rate of electrical energy is higher, which is in line with the high energy consumption requirements of today's data centers.
Let's focus on cooling.
The traditional way of cooling in data centers is air cooling. Cold air generated by machine room air conditioning (CRAC) or machine room air handling unit (CRAH) is transported through the air supply channel to the location of the equipment for cooling.
In the past, air cooling was all room level, that is, blowing and cooling the entire machine room. This way the refrigeration path is too long and the efficiency is too low.
Now popular is pool level, row level and cabinet level air cooling, that is, a cabinet pool, a row of cabinets or a single cabinet as the center, for heat dissipation design.
Cabinet row level heat dissipation, with a row of cabinets as the object, the air duct design
Obviously, the shorter the airflow path, the higher the heat dissipation efficiency.
In addition to air cooling, water cooling and liquid cooling are gradually becoming popular.
The thermal conductivity of the liquid is 25 times that of air, and at the same volume, the liquid carries away nearly 3,000 times the heat of the air. From the noise point of view, the noise of liquid cooling is reduced by 20-35 decibels compared to air cooling at the same heat dissipation level. From the perspective of energy consumption, liquid cooling saves 30%-50% of electricity compared to air cooling.
There are two types of liquid cooling. One is that the liquid is not in direct contact with the heat dissipation device (only participates in heat exchange), and the other is that the liquid refrigerant is in direct contact with the heat dissipation device (even soaked in the refrigerant). The latter has the highest cooling efficiency, almost achieving a PUE of 1.04 (the limit is close to 1), but also the highest cost and technical difficulty.
There are also several refrigeration technologies in data centers that are becoming increasingly popular, such as backplane air conditioning and indirect evaporative cooling.
Indirect evaporation cools the air conditioner
In addition to renewable energy and refrigeration technology innovation, data centers also use many other energy-saving and emission-reducing means. For example, the large-scale adoption of prefabricated modular data centers shortens the construction period and simplifies the construction process.
Prefabricated modular data centers
For example, like the base station, AI technology is introduced to intelligently upgrade the energy management and operation and maintenance systems of the data center, model energy conservation and health, use AI algorithms for data training, and finally form the best parameters to find excellence.
epilogue
Looking to the future, our country is in a critical stage of accelerating the launch of the digital economy. Digital transformation in various industries is gradually spreading, and there is a strong demand for ICT digital infrastructure.
How to complete the support for these needs under the premise of ensuring the "double carbon" goal is a difficult problem facing the entire industry.
It is hoped that industry enterprises can continue to increase R&D investment in the field of energy conservation, explore more energy-saving technological innovations, and embark on a unique "green communication" development path.
Resources:
1. "5G Energy Efficiency, Green New Trend" White Paper, GSMA, ZTE
2. "New Variables for New Infrastructure, Green Communications Under "Double Carbon"", Guosheng Securities
3. White Paper on Energy Saving Technology of 5G Base Stations, China Mobile Research Institute
4. White Paper on Ten Trends in Digital Energy, Digital Energy Industry Think Tank
5. Green 5G White Paper, Huawei