CATL released the world's first solar-plus-storage integrated solution with zero auxiliary power supply at the SNEC International Photovoltaic Power Generation and Smart Energy Conference & Exhibition on May 24. Unlike conventional energy storage solutions, CATL’s trailblazing solution gets rid of the dependence on the cooling system and auxiliary power supply through the self-developed solar-BESS converter, the heat-resistant cell technology and advanced self-heating technology. It achieved real-time integration of fluctuating PV power with battery energy storage system (BESS), thus realizing millisecond-level power control response and increasing the charging-discharging efficiency by 10%.

At present, in order to cope with climate change and achieve the goals of decarbonization, the world is actively increasing the proportion of renewable energies. As one of the main sources of renewable energies, photovoltaic energy still faces the challenges of stability caused by weather conditions. In addition, due to the influence of the system architecture and the auxiliary-power consumption, the conventional PV+ energy storage system faces problems such as low operating efficiency and complex operation and maintenance.

To address the pain points of the industry, CATL launched the innovative zero-auxiliary-power-supply solar-plus-storage integrated solution, which consists of three modules, namely PV modules, energy storage racks, and solar-BESS converters. While PV modules convert sunlight into electrical energy, the energy storage racks can store or release the electrical energy based on the real-time needs, and solar-BESS converters can convert the DC power from PV modules and energy storage racks into AC power and transmit it to the grid. The efficient interaction of the three parts facilitates the active support of grid, power fluctuation suppression as well as peak shaving, providing an optimal solar-plus-storage integration solution.

In order to get rid of the dependence of conventional solar-plus-storage system on the cooling system and its auxiliary power supply, the energy storage racks used in this solution are equipped with the industry's first long service life cells featuring high temperature tolerance, with which the system cycle life can reach 15,000 cycles. By adopting high-temperature-resistant graphite anode material and special electrolyte, the cell can maintain its good attenuation characteristics at temperatures exceeding 35°C without a cooling system or external auxiliary power supply, which can optimize system performance and efficiency, and make it maintenance-free. At the same time, different from the traditional external heating method, the cell can realize even heating through advanced self-heating technology, eliminate heat transfer loss, and further improve the overall efficiency and stability of the solar-plus-storage system.

In CATL’s innovative solution, each string-type PV-BESS converter is equipped with an independent local energy management system (Local EMS), and can realize real-time communication with the upper management system to make the energy storage more intelligent. Each solar-BESS converter has the energy storage batteries to regulate the photovoltaic modules, forming an independent system responsible for its own "gain and loss," realizing the coordinated operation of PV and BESS system. In addition, the system can also conduct real-time analysis of light intensity and working scenarios, identify requirements for distribution of photovoltaic energy and energy storage in different environments, adapt to the maximum efficiency under changing conditions, achieve millisecond-level response, and output power with "zero" deviation.

After three years of hard working and focusing on the entire R&D chain from materials and cells to products, CATL achieved an overall improvement in terms of operational efficiency, response speed, service life, durability and safety of the energy storage system by building solar-plus-storage integrated solution, and obtained remarkable ecological and economic benefits. As a global leader of new energy innovative technologies, CATL is committed to bringing customers excellent quality, outstanding performance and positive results, establishing a global benchmark for new power systems, unleashing the potential of renewable energy, and making outstanding contributions to the global clean energy transition and sustainable development.