During the 13th Five-Year Plan period, China has been struggling with reforms in the electricity industry in the context of a continuing economic downturn. Despite the competition among wind, solar, water and coal energy, it has become increasingly clear that renewable energy will gradually replace the existing fossil energy in the market in the future. As a key technology supporting the smooth operation of traditional electric system, facilitating the connection of renewable energy to the power grids and sustaining the development of the network of distributed energy, electric motor vehicles and energy, energy storage technology has been more highly valued and recognized.

—Energy Storage Industry White Paper 2017 by CNESA

Exploring Shanghai Electric in the Energy Storage Industry

Wind and light are gifts to human beings from the nature, which are renewable and inexhaustible. The progress in science and technology has turned these natural resources into easy-to-use renewable sources of energy. The development and utilization of clean energy, such as wind and solar energy also contribute to the harmonious coexistence of human beings and the nature. But the wind will not blow all the time, and the sun will also set at twilight. There is a mismatch between the supply and demand of wind and solar power in the peak period. Besides, the supply of wind and solar power fluctuates, which has an impact on the power grids. These inhibit the efficient use of the renewable energy and connection of renewable energy to the power grids on a large scale.

If there are large-capacity batteries to store a large amount of power, wind and solar power generation will become stable and controllable. The stored power will enable off-grid power supply to ensure continuous power supply by renewable energy systems of wind power, solar power, etc., especially when there is no wind or sunlight. This will make the originally intermittent wind and solar energy highly controllable. Obviously, breakthroughs in energy storage technology will be the key to the connection of charging facilities, wind power, PV power to the power grids on a large scale. In recent years, the global energy storage industry has witnessed fast development, and a large-sized energy storage market gradually takes shape. According to the statistics of CNESA, as of the end of 2017, the cumulative installed capacity of operational projects around the world has reached 175.4GW (an annual growth rate of 3.9%), and that in China has reached 28.9GW (an annual growth rate of 18.9%).

In previous years, energy storage was not valued to such a great extent. But the industry has seen rapid development due to such factors as policy, utilization rate and environmental protection, leading to a growing energy storage market. So, what exactly is energy storage technology? In a broad sense, energy storage is the process in which energy in a certain form is stored in a medium or a device in the same form or another converted form, and then released in a specific form when needed in the future. Energy storage technology can be classified into several categories including mechanical, electrical, electrochemical, thermal and chemical energy storage by the storage medium.

Among them, electrochemical energy storage technology has witnessed the greatest progress. As electrochemical energy is stored in batteries, electrochemical energy storage technology is superior than its counterparties in terms of applicability, efficiency, life, charging and discharging, weight and portability. Electrochemical energy storage technology dominated by lithium-ion, lead-carbon and flow batteries has achieved major breakthroughs in safety, efficiency of energy conversion and cost-effectiveness. The total operation of global electrochemical energy storage from 2000 to 2017 was 2.6GW and the capacity was 4.1GWh, with an annual growth rate of 30% and 52% respectively. In China, there had been over 130 projects being put into use in 2017. This shows that the application of energy storage has become more popular around the world. Since November 2017 when the National Energy Administration officially introduced the Guiding Opinions on Promoting the Development of Energy Storage Technologies and Industry, relevant government authorities have been formulating policies conducive to the development of the energy storage industry. This marks a brand new chapter for the all-round development of the industry in terms of technological innovation, industrial upgrading, application areas, market mechanisms, standards and systems, and policy support.

At the beginning of August 2018, Shanghai Electric officially embarked on the "Internet+" smart energy demonstration project in Sanxing Town, Chongming District. Located in a pastoral complex in Sanxing Town, the project connects wind and solar energy stored to microgrids in a low-carbon park for distributed power generation. It is also the first project undertaken by Shanghai Electric Power Generation Group after it established the Business Unit of Energy Storage and Fuel Cells. Among the 28 projects in the List of the First New Energy Microgrid Demonstration Projects released by the National Development and Reform Commission, 25 have added units of power storage or energy storage, which also shows that energy storage technology will be the key support for the new energy utilization model in the energy network.

According to Energy Storage Industry White Paper 2017, "the commercialization of energy storage will stir up not only the stagnated power sector reforms, but also energy sectors like the oil and gas industries. It will not only change the shape of the existing market, but also break ground for new markets with the capacity for nearly unlimited growth. It will not only make an energy revolution a real possibility, but also deeply transform humanity's production methods and lifestyles."

Due to the huge market demand and potential, the efforts of Shanghai Electric in the field of energy storage have received considerable attention. In recent years, with the goal of deploying a complete industry chain of mobile and fixed energy storage as a supplier of high-end energy storage products, Shanghai Electric has been accelerating the development of incremental business of new energy through integrating competitive research teams and technical resources, and focusing on the multidisciplinary study of the new energy industry chain.

Microgrid Energy Storage: the "Internet+" smart energy demonstration project in Sanxing Town, Chongming District

In March this year, Shanghai Electric Power Generation Group established the Business Unit of Energy Storage and Fuel Cells. Relying on the support of the Group for technological innovation, human resources and integration of market resources, and the Group's capacity for establishing a comprehensive energy control system, the Business Unit provides technical solutions in such fields as core technology of distributed power supply, battery management technology in all-vanadium flow energy storage battery, lead-acid battery and lithium battery energy storage systems, production of unit modules in megawatt-level energy storage system and construction of energy storage power station with hierarchical architecture, comprehensive loss reduction and improvement of power quality in the distribution network.

In April this year, Shanghai Electric Power Generation Group undertook the "Internet+" smart energy demonstration project in Sanxing Town, Chongming District. The project is developed to fully meet the needs of smart ecological villages. In terms of environmental protection, power generated with renewable energy, such as PV and wind, will meet all the needs of farmers in the village committee, the pastoral complex and surrounding areas for living, production and agriculture to achieve zero carbon emission. In terms of reliability, the system equipped with advanced energy storage equipment ensures that the power generated will first be supplied to the villages and then connected to the power grids in case of surplus power, which not only reduces the impact on the grids but also effectively lessens the unbalance in the three phase voltage in villages and improve the power quality. In terms of cost-effectiveness, the system adopts a smart energy management system that controls and regulates the energy grid-connection system and isolated network system in the rural area as a whole and obtains certain economic benefits from the peak-valley price difference.

The project integrates the latest products and technologies of Shanghai Electric in the field of renewable energy and smart microgrid. Over 80% of the equipment and systems are its own products and technologies, including CIGS solar thin-film power generation system, energy storage battery and management system, PV inverter and energy storage converter, energy management system, remote data monitoring and analysis system. The project is currently under construction, and its commissioning and connection to the power grids are expected to be completed by the end of September. The completed project will push forward the process of developing a civilized and ecological smart town in Sanxing Town, Chongming District. It will also become a typical case demonstrating the smart energy system & equipment and capacity of Shanghai Electric.

In addition, Shanghai Electric has put together teams of R&D, engineering and operation to study various business models, and is able to provide customers with overall solutions for integrated energy services and all-round quality services such as system design, development, operation and maintenance, and upgrading.

Lithium-ion Battery: An Energy Storage Superstar

According to industry data in the past two years, among all energy storage technologies, lithium-ion battery has seen the greatest year-on-year growth rate and accounted for the largest proportion in the field of grid-connected renewable energy in terms of the new installed capacity. At present, lithium-ion battery has become the most widely applied electrochemical energy storage technology, and will always be an important R&D direction of energy storage technology.

In 2012, Shanghai Electric Central Academe undertook a key project, "Research on the Industrialization of Lithium Batteries for Energy Storage", and made breakthroughs in the technologies for the preparation of key materials of lithium batteries, the technologies for the design and production of monomer batteries, modular battery group technology, power management technology, energy storage system integration technology, etc. In 2017, Shanghai Electric Guoxuan New Energy Technology Co., Ltd. was formally incorporated. Relying on the advantages of Shanghai Electric and Guoxuan High-Tech in the fields of energy equipment and power batteries, the company provides customers with efficient, reliable and customized energy storage solutions.

In the first half of this year, it completed the projects of 20-foot container for energy storage of Copper and 40-foot container for energy storage in Huguang Road. In these projects, lithium batteries featuring large charge and discharge rates, fast charge and discharge response and long life cycle are used to help enterprises lower the electricity costs through the peak-valley price difference, that is, charging during peak hours and discharging during valley hours by the customers. In addition, the energy storage system can also help users lower the risk of power outages, improve the power quality, reduce the capacity charge and engage in the demand-side response. The company will kick off various new projects, including the microgrid project in Chongming District and that of the Academe, and the demonstration project of energy storage in Zhuqiao. Safe and long-life battery units, system management and control units, system access units and container system units developed by the company on its own, as well as standardized and highly integrated module design will be used to provide users with customized overall solutions for energy storage.

Due to its capacities for flexible peak regulation, frequency modulation, emergency response, and improvement of power quality, energy storage power station on the power grid side has attracted more and more power companies to explore the new market of energy storage applications. From the perspective of the existing energy structure, although China's installed capacity for power generation ranks first in the world, thermal power generation accounts for a large proportion. As renewable energy is being used on a large scale, energy storage will have a huge room for development. From the perspective of reforms in the electricity system, the planned domestic electricity market has been gradually shifting to commercial and spot market. During the process, energy storage will play a greater role. Based on this, the company will invest considerable efforts in the development of the grid-side energy storage market by leveraging the advantages of energy storage equipment including short construction cycle, flexible configuration and fast response to gain a foothold in the market.

Flow Battery: Entering the Stage of Industrialization Demonstration

Large-scale energy storage technology is the core technology to realize the wide application of renewable energy. The wide application of the flow battery is promising in the field of large-scale energy storage because of its great safety, large-scale energy storage, high efficiency and long life. All-vanadium flow battery, one of the most mature flow battery technologies, is in the stage of industrialization demonstration.

Since its establishment in October 2011, the Flow Battery Energy Storage Team of Shanghai Electric Central Academe has been committed to the independent R&D of flow battery energy storage products and attaining the core technology of battery product development to support the group's development in the energy storage industry. Its achievements include 5kW/25kW/50kW voltaic piles and the 250KW/500KWh container-type all-vanadium flow battery energy storage system integrated with the 25kW voltaic pile. It has also make breakthroughs in a series of key technologies such as battery design, battery sealing, battery automation manufacturing process, system design and integration, which enables it to provide customized energy storage products and overall energy storage solutions.

In November 2017, the Academe set up the Energy Storage Flow Battery Product Department, consisting of core members specialized in electrochemistry, electrical automation, mechanical automation, thermal energy management, materials science, computer simulation, etc. Since its establishment, the Department has been working on product development at four levels, key materials, voltaic piles, smart battery management and energy storage system. It has obtained patent on core technologies and independent intellectual property rights in the field of key materials. A special smart power management system for vanadium battery based on the technical characteristics of such battery is developed by the Department to ensure the safe, stable and efficient operation of the vanadium battery energy storage system. In addition, the Department has developed a highly integrated 250KW container-type all-vanadium flow battery energy storage system and megawatt-level energy storage system. The system design incorporates such concepts as compatibility and scalability, allowing plug-in connection in the application to maximize the value for customers. It is worth mentioning that the all-vanadium flow battery boasts low level of pollution, high safety and long life. The total installed capacity of flow batteries in the world stands at about 68MW, and that of all-vanadium one accounts for 40%.

At present, the Product Department has one pilot production line with a production capacity of 50MW/year. It is expected to be upgraded at the end of 2018, and the capacity may reach 200MW/year after the upgrading. The energy storage flow battery system independently developed by the Shanghai Electric Central Academe has been widely applied in various fields such as distributed microgrids, solar energy storage and charge and use of power generated during valley period in peak hours. The Institute has undertaken 5 research projects entrusted by its peers, 2 projects by Shanghai Science and Technology Committee, and 1 project by Shanghai Economic Commission.

The all-vanadium flow battery developed by Shanghai Electric integrates the 250KW power module, capacity module, electrolyte transport module, heat dissipation module, and battery management system. Its voltaic pile is designed with a structure that prevents electric leakage, which reduces the risk of electrolyte leakage, improves the reliability of the system, achieves such functions of the system as automatic charging and discharging, automatic monitoring and energy management, and enables the integration with megawatt-level energy storage systems used in distributed microgrids, large wind farms, PV power stations, etc.

Inorganic Molten Salt: Widely Applied in the Concentrating Solar Power (CSP) Field

The most recognized heat storage media in the field of CSP generation are inorganic molten salts, which boast the advantages of high operating temperature, high stability, high specific heat capacity, high heat transfer coefficient, low viscosity, low saturation vapor pressure, and low price. From the study of individual inorganic molten salt to that of mixed molten salts and to the composite molten salts energy storage technology, the application of molten salts has been significantly expanded in terms of temperature range and fields such as CSP generation, transformation of thermal power generation, valley electric heating and connection of wind power to grids.

Shanghai Electric Central Academe has been deploying the energy storage industry since 2010, including technology development and business incubation. In 2012, it established the CSP Storage Team, which is dedicated to the development of CSP storage technology. On the basis of the preparation and testing of molten salts, the Team has developed a CSP storage system, a clean energy heat supply system, and a system for flexible transformation of thermal power generation to provide customers with design consulting and overall solutions in fields related to molten salt heat storage.

In terms of molten salts, the Team has developed molten salts with melting point below 100℃, which boasts such advantages of low maintenance cost, stable performance and low corrosion and addresses the problem of blocking the pipeline by high-melting-point salts that are easily solidified. In terms of system design, the Team has independently developed a single-tank molten salt storage system and a double-tank one. The two systems have been successfully applied in pilot production and actual projects. They boasts small footprint, no environmental pollution, low operating cost and wide range of heat storage. For example, the small molten salt system producing steam for industrial use of heat may heat the molten salts with low-cost electricity during valley hours at night and release energy during the day when the power price is high to avoid using high-cost electricity, thus reducing the operating costs of the system. Let's take the 50kg/h and 0.7MPa steam generator as an example. The system storing energy of about 200kWht is able to operate for four hours at full capacity when the electricity price is high. If the peak-valley price difference is 0.5 yuan/Kwh, compared with an electric boiler that operates for 300 days per year, the system may save 30,000 yuan per year. In this way, the investment in the system can be recovered within three years. As the internal furnace body of the product has an effective volume of less than 30 liters, which will not be supervised as special equipment and require no reporting nor annual inspection. Therefore, it is mainly suitable for projects using a small amount of heat in such industries as brewing, textile, food and chemicals.

We are confident that the energy storage industry will have a bright future. As China further promotes the energy transformation, integration of renewable energy to the power grids on a large scale and reforms in the electricity system, huge business opportunities will be created for the energy storage industry and the market. It is eagerly hoped that the energy storage industry supported by favorable policies and market development will achieve breakthroughs in commercial application as soon as possible and become the new force driving the energy revolution.