PARTNER CONTENT: With the global initiative to reduce carbon emissions and achieve carbon neutrality, the energy structure is oriented towards low carbon, electrical energy, and digitalization. At present, with the large-scale deployment of 5G networks and Data Centers (DCs), the number of 5G sites increases exponentially, and the power consumption of devices at network sites and in equipment rooms increases significantly, causing a sharp rise in network-wide power consumption. As an important part of the energy system, energy storage needs to follow the “low carbon and intelligence” .

Sites, equipment rooms, and DCs now have higher requirements for energy storage density, energy efficiency, and intelligence. Traditional lead-acid batteries, featuring low energy density, large size, heavy weight, short cycle life, low charging and discharging efficiency, and extensive management and O&M, can no longer satisfy the network development requirements. Therefore, they are gradually replaced by lithium batteries with higher performance. Lithium energy storage has become a trend in the telecommunications industry.

The current lithium batteries, however, are simply composed of a Battery Management System (BMS) and battery cells. They provide simple functions and exert high expansion costs, and therefore are used in limited scenarios.

Drawing on an insight into future network evolution, and leveraging battery technology, network communications, power electronics, intelligent measurement and control, thermal design, AI, big data, and cloud management, ZTE has innovatively proposed a “new dual-network architecture and new L1-L5 evolution hierarchy” and is promoting the rollout of smart lithium batteries, thereby meeting new service requirements of 5G networks and driving energy structure transformation. “By proposing the new hierarchy of five levels, we hope to drive the evolution of energy storage towards intelligence in the telecommunications industry,” said Liu Mingming, ZTE’s Vice President and General Manager of Renewable Energy Products.

Liu added that telecom energy storage is evolving from the previous “single architecture” to the current mainstream “end-to-end architecture”, and ultimately to the “new dual-network architecture”.

Figure 1: Evolution of the Telecom Energy Storage Architecture

In the previous single-architecture scenario, the lithium battery system, as an isolated execution component, mainly provides the power backup function. In this case, the cycling performance is not fully utilized, undermining the asset value. Due to extensive power backup management, the power backup is either redundant or insufficient at different sites, leading to asset waste. The operational status of the lithium battery system cannot be visualized or identified, resulting in passive responses in O&M.

After evolution to the current mainstream end-to-end architecture, a site energy storage information network is established in “lithium battery-power supply/gateway-EMS” mode to remotely monitor the status of lithium devices, set parameters, and detect faults. The enhanced local BMS and interoperability with the Energy Management System (EMS) have taken the intelligence of lithium batteries to a higher level. Although the end-to-end architecture facilitates the intelligent evolution of lithium batteries, it needs to be further upgraded because it falls short of inter-site coordination and scheduling of network-wide energy storage, and cannot satisfy the application of such technologies as big data and AI assistance.

In this regard, telecom energy storage will inevitably evolve towards a new dual-network architecture.

This architecture features an energy network and an information network with full-scenario connectivity of the public power grid, as well as the power generation, power consumption, and energy storage devices at network sites, enabling the interconnection between network-wide energy storage information and energy resources. Based on the integration of these two networks, an energy cloud is established to manage energy streams through information streams. The new architecture is the cornerstone of transformation from passive energy storage to active energy storage and active security, maximizing full-lifecycle value of energy storage. It ultimately achieves bidirectional flow of information streams and energy streams in network-wide energy storage, paving the way for the future comprehensive application of site energy storage, new energy applications, and zero-carbon network evolution.

To put it simply, the energy network will be connected with the information network for more efficient monitoring and management, enabling intelligent telecom energy storage.

“Based on the three architectures, we have innovatively defined five levels to achieve expected self-intelligent telecom energy storage, namely, L1 (passive execution), L2 (assisted self-intelligence), L3 (conditional self-intelligence), L4 (high self-intelligence), and L5 (interconnection),” said Liu.

L1 corresponds to the single architecture. At this level, common lithium batteries, acting as a passive execution component to replace lead-acid batteries, offer higher performance but similar functions. The lithium batteries are still dumb devices with limited application scenarios. Some vendors still provide L1 products. L2 and L3 correspond to the end-to-end architecture. L2 provides preliminary management that makes lithium batteries intelligent. At L2, lithium batteries are capable of independent execution, partial perception, and partial analysis. With a simple BMS, lithium batteries are connected through the power supply system to the EMS that provides basic functions like voltage and current balance, real-time parameter check, and over-current/over-voltage protection. Currently, many vendors are providing L2 products and solutions. Compared with L2, L3 is much more intelligent. With the introduction of power conversion and partial decision-making and enhancement of the perception capability, L3 is capable of independent execution and perception and partial decision-making. It offers more powerful functions:

  • Stronger performance, such as higher energy density, super multi-group cascading, and equalized control with higher precision.
  • More application scenarios, such as intelligent hybrid use, intelligent parallel operation, intelligent peak-load shifting, intelligent peak-load shaving, and intelligent boosting.
  • More secure and reliable functions, such as SOC/SOH, remote alarm, intelligent theft prevention, and preventive O&M.

ZTE offers sophisticated L3 products and solutions with innovative functions that cater for all the 5G network scenarios and make the power system of 5G networks more intelligent, maximizing the efficiency of network power supply and O&M and reducing the Total Cost of Ownership (TCO).

L4 makes a big leap in the self-intelligence level of telecom energy storage. L4 is integrated with new technologies such as AI, big data, and IoT, and is upgraded from the end-to-end architecture to the new dual-network architecture. L4 uses an intelligent management mode with three layers, namely, cloud, EMS, and device, which can be deployed in a stepwise manner with the improvement of the management level. L4 represents a shift from partial decision-making to independent decision-making. With less human intervention, L4 enables more secure operation, more efficient O&M, wider application, and greater economic benefits. At present, ZTE is focusing on L4, of which the specific functions and advantages are reflected in four aspects:

  • Dual-network integration and cloud-network synergy
  • Active learning and active energy storage
  • Active security and intelligent cloud maintenance
  • Capacity management and asset optimization

L5 is the ultimate phase of intelligent evolution of energy storage in the dual-network architecture, achieving full independence in execution, perception, analysis, decision-making, and intent. With the revolution of energy Internet technologies and new energy uses, energy storage will give full play to its potential (see Figure 2). Specifically, it will support the integration of multiple energy storage methods, comprehensive energy supply optimization, and network-wide AI learning that can evaluate carbon indicators, and develop the optimal carbon emission strategy and the optimal carbon emission result through continuously improved algorithms, achieving complete interconnection between energy and information networks, and bidirectional flow in each network, and allowing customers to accomplish their best outcomes.

Figure 2  Overview of L5 Interconnection

As pointed out by Liu, “The new L1-L5 hierarchy for intelligent energy storage aims to drive continuous development and progress of the telecommunications industry through technological accumulation and practice. In this way, we can create greater value for customers, and achieve maximum energy sharing, most efficient energy use, and cleanest energy supply, thus embracing a sustainable energy future. ZTE remains committed to shouldering more responsibilities despite the challenges ahead to achieve intelligent evolution of renewable energy.”