To build a new type of energy storage, it is urgent to bridge the gap between economy and safety

At present, my country is accelerating the construction of a new energy system with a new power system as the core to help promote "carbon peak and carbon neutrality". In this process, energy storage, as a flexible power regulation resource, will play a long-term, positive and irreplaceable social value.

On December 13, the "Green Energy Management" reception room live broadcast column with the theme of "Flexible energy storage for multiple scenarios" was held at Nengjian Qilin College. The live broadcast was hosted by Cao Kaihu, deputy general manager of Nengjian Technology, and Zheng Hua, professor of North China Electric Power University, secretary-general of the IEEE PES (China) Energy Storage Market and Planning Technical Subcommittee, and secretary-general of the Power Market Committee of the Zhongguancun Energy Storage Technology Industry Alliance; Shi Baochun, chief technical consultant of Schneider Electric's critical power business department, and other authoritative experts in the industry discussed topics such as "What are the typical application scenarios of user-side energy storage", "How to make energy storage safer", "What are the business models of energy storage", and "What is the cost-effectiveness of capacity expansion through energy storage".

Discussion on application scenarios and opportunities of user-side energy storage in the spot market

New energy storage is an important technology and basic equipment for building a new power system and promoting the green and low-carbon transformation of energy. It is also an important support for achieving the "dual carbon" goal. In the view of Zheng Hua, a professor of electricity at North China University, new energy storage is born out of a high proportion of new energy, and the profitability of new energy storage is inseparable from the electricity spot market. Only the spot market can truly reflect the difference between supply and demand and the deviation of their value, and can better guide market members and make full use of market rules to ensure the balance between supply and demand.

From the trend point of view, promoting new energy storage, load aggregators, virtual power plants, user-adjustable load resources to participate in auxiliary services has become a direction. In order to better promote energy storage to participate in medium- and long-term electricity transactions, spot markets and auxiliary services, Zheng Hua believes that the important thing about spot new energy storage is to provide auxiliary service functions, that is, to ensure the function of power balance, which is its real focus. For the arbitrage of electricity required in the traditional spot market, it is not necessarily suitable for resources on the load side. Overall, the structure of the market is still mainly based on the source side, supplemented by the load side. From the perspective of the mechanism of new energy, it is a structure dominated by the spot market and medium- and long-term financial medium- and long-term difference contracts. The proportion of spot electricity is relatively around 10%. From this perspective, there is still a lot of room for discussion in the future.

Schneider Electric has extensive experience in helping various industries achieve safe and stable electricity use and energy efficiency optimization through a series of integrated software and hardware solutions. Shi Baochun, chief technical consultant of Schneider Electric's critical power business unit, said: "Due to the long investment payback period and other reasons, user-side energy storage investment based on commercial needs is currently mainly pilot projects. More user-side energy storage is based on technical needs, such as backup and capacity expansion for uninterrupted power supply."

User-side energy storage solutions under new power system architecture

Currently, user-side energy storage is regarded by the industry as the most promising area for energy storage development because it is expected to resolve the contradiction that "there is electricity in the power grid, but bottleneck equipment exists in the grid at all levels, resulting in the inability to safely transmit electricity to users during peak hours."

Zheng Hua, a professor of electric power at North China University, believes that for user-side energy storage, the future development trend can be summarized into three major characteristics: First, the mainstream model. The main business model of new energy storage is based on shared energy storage. According to Document No. 475 issued by the Energy Bureau in April this year, non-independent energy storage can be transformed into independent energy storage. Second, shared energy storage itself is an independent market entity and a configuration method that can obtain more benefits. Since the second half of last year, user-side energy storage has been very popular, especially in Jiangsu and Zhejiang, and many new formats and new business models have emerged. Third, the market-oriented long-term mechanism has been recognized by everyone. Only this path can truly solve the long-term guarantee of new energy storage and make it profitable to participate in the market.

Enterprises can significantly reduce electricity costs by installing user-side energy storage projects. However, we need to pay attention to how to continuously improve the ability of user-side energy storage to participate in electricity market transactions and improve the utilization rate of energy storage systems? How to actively store a large amount of user load data, and optimize the configuration of regional energy storage systems in combination with the future progress of electricity market construction and changes in electricity price policies? How to provide demand-side response services, frequency regulation, and improve power quality and other auxiliary services to reduce users' comprehensive electricity charges and improve the utilization rate of user-side energy storage?

Shi Baochun, chief technical consultant of Schneider Electric's critical power business unit, introduced that there are three typical application scenarios focusing on user-side energy storage: the first scenario is mainly used in factory areas and photovoltaic supporting facilities. Through the integration of photovoltaic storage, self-generation and self-use, and storage of surplus electricity can be achieved, thereby saving costs and reducing carbon emissions. The second scenario is mainly demanded by capacity increase to meet peak loads. For example, in charging stations, manufacturing industries or commercial buildings, some configurations will use UPS, and most will use PCS power conversion equipment to increase energy storage capacity. The third more typical demand is the need for power quality management on the basis of capacity increase, such as applications in data centers, semiconductor industries, or industries such as medicine and high-end manufacturing.

Energy storage business model and technology application

Under the guidance of the "dual carbon" goal, user-side energy storage has received unprecedented attention. Schneider Electric focuses on user-side scenarios and classifies user-side scenarios and needs into three types from simple to complex according to the requirements of application technology: photovoltaic storage integration, capacity expansion and peak load relief, and power quality management.

Zheng Hua, a professor of electricity at North China University, said that energy storage on the load side is mainly divided into two types. One is the single model, such as the general industry and commerce, and then equipped with a certain amount of energy storage to reduce the user's application cost, which has led to various business models, mainly through the peak-valley electricity price difference to divide the electricity price. The other is the aggregation model, which uses aggregators as carriers to participate and get money from the market. Overall, under the conditions of the aggregation method, the reliability of resources and the flexibility of regulation can be better revitalized.

For enterprises, energy storage with a rate of return can usher in market opportunities. Zheng Hua pointed out that from the perspective of the overall market participation conditions, the current focus is on demand response. In the future, the main push will be the projects mentioned in the basic operating rules of the spot power market released two weeks ago, including projects in some provinces such as Shandong, Zhejiang, and Shanxi. It can be seen from the provincial formulation that the aggregation entities on the demand side, including the aggregation entities of new energy storage, are currently allowed to participate in the spot market, and they can also do secondary frequency regulation and standby. There are also some related rules that are not covered in the support of the grid type on site, including temporary regulation and emergency regulation. From the perspective of aggregation, it has many core technologies, including communication metering, simulation prediction coordination and dynamic balance, which can truly constitute a very large core force of the resources aggregated on the load side.

In this regard, Schneider Electric has carried out technical improvements and industrial practices. Shi Baochun, chief technical consultant of Schneider Electric's critical power business department, said that under the guidance of such a guiding ideology, Schneider Electric's energy storage solutions on the user side are also constantly improving. "For example, Schneider Electric's energy storage cabinet is composed of a lithium battery system, a BMS battery management system, a power converter, a control system, and an auxiliary system. Among them, the battery mainly uses two lithium battery systems: lithium iron phosphate and lithium manganese oxide mixed ternary lithium. There are also two types of power converters. One is to use the common PCS to form a standard energy storage cabinet. The second is to use Schneider Electric's energy storage UPS high-end solution for the needs of power quality management or uninterrupted capacity expansion, and finally form a system of energy storage cabinets required by users.