PRESS RELEASE: Currently, the world is facing escalating challenges in energy supply, climate change and increasing environmental pressure. Simultaneously, emerging technologies such as 5G communication, big data, and artificial intelligence have exponentially increased the demand for hardware computing power, leading to a sharp rise in energy consumption. Therefore, energy saving has become a focal point of concern for operators. Various equipment suppliers have responded to this challenge, with ZTE continuously introducing innovative green and energy efficient solutions.
Overall, ZTE’s improved energy efficient solutions for radio sites include an outdoor all-in-one cabinet to replace an air-conditioned equipment room, an all-on-pole solution for site equipment and centralized placement of baseband processing units (BBUs) inside the equipment room to assist in energy savings, as shown in Figure 1. ZTE incorporates intelligent and efficient power supplies, solar power, liquid cooling technology, and other means in its site solutions to minimize energy consumption and maintenance costs.
Figure 1 Overview of ZTE’s Energy Efficient Radio Site Solutions Across All Scenarios
1. Equipment room to cabinet: site energy efficiency improved to 90%+
Generally speaking, communication equipment is of high precision and has high environmental requirements. Therefore, since the deployment of communication networks, the main equipment has been placed in equipment rooms equipped with air conditioning. However, since radio access networks need to cover every corner of the world, including not only densely populated cities and sparsely populated rural areas but also deserts, high mountains, and other remote areas, this requires air-conditioned rooms or shelters to be ubiquitous. This not only involves substantial initial construction costs but also high operational expenses, especially due to the high power consumption of air conditioning. Therefore, the solution to replace equipment rooms or shelters with outdoor cabinets has emerged.
As early as 2008, ZTE Corporation launched the first generation of outdoor full-function cabinets, integrating functions such as power supply, power distribution, transmission equipment, baseband processing, and lightning protection. Years of practice have proved that the outdoor cabinet solution has significant advantages in reducing costs and improving efficiency. In particular, the cabinet’s heat dissipation adopts a well-designed air heat exchange system, which not only ensures the isolation of air to protect the equipment inside from corrosion, but also achieves cooling without relying on air conditioning. Thereby the site energy efficiency is improved to over 90%.
With the arrival of the 5G era, ZTE has introduced a new generation of outdoor modular cabinet as shown in Figure 2, which includes a main equipment cabinet stacked vertically with a battery cabinet. The heat dissipation capacity of the main equipment cabinet has been significantly enhanced, employing a new generation of intelligent power supplies with an output power of up to 21KW, providing a maximum of 21 DC terminals without the need for power distribution to support multiple power outputs. This reduces the occupation of space in the site’s equipment cabinets, and the peak efficiency of its rectifier module reaches 98%.
Figure 2 New-Generation Full-Function Outdoor Modular Cabinet, No Air Conditioning Required
Additionally, the new generation of intelligent power supply supports smart load shifting function, as shown in Figure 3. On one hand, when the power demand exceeds the supply, the battery automatically discharges to make up for the power gap, which can reduce the power supply equipment capacity demand at the site. On the other hand, during peak power consumption, the power source hibernates and the site is powered by the battery, and during off-peak power consumption, the battery is charged. This not only balances the power load and reduces the use of peak-hour grid electricity but also significantly saves electricity expenses because valley-hour electricity costs are relatively low. Results from a four-year tracking of a project in Zhejiang Province, China, show that a single site saves more than $1,000 in electricity expenses annually.
Figure 3 New-Generation Intelligent Power Supply Realizes Smart Load Shifting
The battery cabinet is equipped with the industry-leading 3U high 150Ah capacity smart lithium battery products, which features high energy density, small size, and light weight. It supports mixed usage with various types of batteries, protecting existing battery assets, and enables intelligent boosting. In long-distance power supply scenarios, it achieves a constant voltage of 57V without the need for additional boosting devices, reducing line loss and contributing to energy savings.
In addition to the above-mentioned stacked cabinet, ZTE has also launched a new generation of fully functional outdoor integrated cabinets as shown in Figure 4, which not only utilize the new generation of intelligent power supply and smart lithium batteries but also support flexible temperature control, further enhancing energy efficiency. The near-end temperature control unit of the cabinet can select either the heat exchange system or modular-designed air conditioners, which allow cooling capacity to be smoothly upgraded to support expansions of the BBU. In the future, a new air system with a self-cleaning function to achieve heat dissipation will be introduced in the cabinet, while requiring minimal maintenance or even zero maintenance. Overall, the cabinet will flexibly match the optimal cooling solution according to the scenario and requirements, achieving flexible temperature control.
Figure 4 New-Generation Outdoor Integrated Cabinet with Simplified Deployment, Saving Energy and Costs
One more thing worth noting is that all outdoor cabinet types support top-mounted solar panels. This not only shades the cabinet from direct sunlight, reducing the additional cooling needs caused by solar heat, but also, with minimal increase in footprint, incorporates solar power as a supplementary energy source to the grid, thereby minimizing energy consumption. These solar panels on the cabinet roof utilize a new generation photovoltaic solution, employing Maximum Power Point Tracking (MPPT) technology for individual units, minimizing the impact of shading on power generation to the greatest extent, resulting in a comprehensive 20% increase in electricity production and enabling a rapid, seamless switch to solar power.
2. All-on-Pole: 97%-efficiency pad power or zero-carbon green energy
In order to further reduce energy consumption and operational costs, ZTE has introduced an all-on-pole solution for all necessary equipment at the site as shown in Figure 5. This solution involves mounting outdoor BBU, RRU, antennas, microwave transmission, pad batteries, and pad power supply all on a single pole, achieving a “zero” footprint and requiring “zero” on-site maintenance. The pad power supply utilizes natural heat dissipation, eliminating cooling losses and providing power in close proximity to the main equipment, thus minimizing line losses. As a result, the site efficiency approaches the peak efficiency of pad power supply at 97%. When deployed for rural coverage, low-power equipment can be selected, resulting in lower total power consumption at the site. This enables power supply using green energy from as little as two solar panels, without relying on the grid. Lithium batteries can assist in meeting power demands during periods of insufficient solar energy.
This solution offers simple installation, occupies minimal space, and eliminates the need for dedicated cooling components. It can be used not only for filling coverage gaps and hot spots but also for rapidly deploying networks in rural areas, saving significant operational and power costs. An operator in East Asia achieved nearly $2000 in annual savings in electricity and rental expenses per site, through streamlined transformation from indoor facilities to all-on-pole outdoor sites.
Figure 5 All-on-Pole Solution Powered by Pad Power or Green Energy
3. New cabinets with new technologies contribute to energy savings in equipment room
In the realm of equipment room energy efficiency, the centralized placement of BBUs not only facilitates centralized management and eliminates on-site maintenance but also reduces the total number of main and ancillary equipment, thereby reducing energy consumption. ZTE has introduced an indoor energy-saving cabinet for the centralized placement of multiple BBUs. With a compact structure, the cabinet has a built-in air conditioning, supporting near-end cooling. The cooling capacity utilization rate can reach 98%, reducing the operational time of room air conditioning or even enabling its non-operation, thereby minimizing the energy consumption of room air conditioning to the maximum extent.
Recently, addressing the localized hotspots and energy consumption issues resulting from the centralized placement of BBU in the Centralized Radio Access Network (CRAN) scheme, ZTE has pioneered a cabinet-level liquid cooling solution. This new green and energy-efficient equipment room temperature control solution utilizes liquid cooling technology and natural cold sources for heat dissipation. The BBU liquid cooling cabinet employs a non-contact liquid cooling solution, harnessing the efficient heat dissipation advantages of liquid cooling while avoiding the reliability risks associated with direct liquid contact with equipment. Not only does it offer convenient deployment and operation, but it also delivers significant energy-saving effects. The commercial deployment of China’s first BBU liquid-cooled heat dissipation solution was completed in Anhui, China, demonstrating a reduction of over 30% in the equipment room’s Power Usage Effectiveness (PUE) according to actual measurements. ZTE has been committed to applying liquid cooling technology in the field of telecommunications. With continuous technological accumulation and innovation, ZTE has accomplished breakthroughs in liquid cooling technology across four levels: board-level, chassis-level, cabinet-level, and data center-level, forming distinct technical features. ZTE has also introduced an integrated ICT liquid cooling solution, allowing users to select according to their specific usage requirements and existing equipment conditions.
Summary
Green energy conservation is an inevitable requirement for sustainable development. ZTE Corporation has been committed to innovating and improving energy efficiency. The site’s green energy conservation solutions are just one of its many energy-saving solutions. Other intelligent energy-saving solutions such as PowerPilot, which includes new functions like hibernation and intent-driven features, have also been widely recognized. These efforts will comprehensively support the evolution of operator networks towards low-carbon, and contribute to the global low-carbon environmental cause.