Amid the global transition to renewable energy, China's power generation and capacity structure is rapidly shifting towards cleaner sources. However, the widespread application of high-percentage renewable energy and power electronic equipment has significantly impacted the safe and stable operation of power systems, posing a major challenge to the global development of renewable energy.
Grid-forming energy storage, known for its capabilities to actively support grid voltage, frequency, and phase stability, has become one of the key technologies underpinning the modern power system.
Grid-Forming Energy Storage: A Growing Trend
Since the beginning of this year, several regional governments have proposed policies encouraging or mandating the integration of grid-forming energy storage systems in renewable energy projects. These initiatives have garnered significant attention and adoption across the industry.
As of June 2024, numerous provinces and autonomous regions, including Xinjiang, Inner Mongolia, and Tibet, have released multiple policies to support or mandate the construction of grid-forming energy storage facilities. According to incomplete statistics, since the second half of 2023, the pace of industry tenders has accelerated. By June 2024, 2.28 GW/7.58 GWh of grid-forming energy storage projects had been tendered across the country.
However, beneath the surface of this rapid growth, challenges remain. Industry insiders note that while grid-forming energy storage boasts significant theoretical advantages, it is still in the early stages of development and faces practical application challenges.
First, grid-forming energy storage must balance energy density with high cycle efficiency—a difficult trade-off to achieve in practice. Additionally, this technology often needs to be integrated with other energy storage solutions such as wind and solar power. Optimizing the configuration and operation strategies of hybrid energy storage systems is a key challenge at this stage. Furthermore, safety concerns related to battery overcharging and discharging, superconducting magnet stability, and supercapacitor short circuits remain significant technical hurdles.
Four Breakthrough Technologies
Since 2011, Huawei Digital Energy has made significant investments in research to ensure the safe and stable integration of renewable energy. Over the years, Huawei Digital Energy has continuously accumulated expertise in grid-friendly technology, advancing from "following the grid" and "supporting the grid" to "enhancing the grid," contributing to the development of new power systems.
On July 28, 2024, the China Electrotechnical Society organized a technical appraisal meeting in Beijing for the "Key Technologies and Applications of Smart String-Based Grid-Forming Energy Storage Systems Suitable for High-Proportion Renewable Energy in Multiple Scenarios" project.
According to reports, a committee of experts from the Chinese Academy of Sciences, the Chinese Academy of Engineering, and the State Grid Corporation unanimously recognized that the project meets the engineering application needs for enhancing the stability of new power systems and renewable energy integration under high-proportion renewable energy conditions. The project is considered internationally leading, with major innovations including:
Multi-Site Self-Synchronous Amplitude and Frequency Modulation Technology: This innovation enables self-synchronous parallel grid formation, enhancing active rapid reactive response, active power support, fault ride-through, impact load resistance, and synchronized black start capabilities. It achieves multi-scenario, full-condition grid formation, active grid support, and effective suppression of parallel circulation, enabling large-scale, multi-site self-synchronous stable operation.
Broadband Self-Stabilization and Stability Control Technology: This technology ensures stable grid integration and oscillation suppression across different grid scales and strengths. It enhances the capability to stably operate alongside photovoltaic, wind, and synchronous generators, expanding the application scenarios for grid-forming energy storage systems.
Decoupled Voltage and Active Power Control in a New Dual-Stage Conversion Architecture: This technology supports grid stability and ensures energy storage system safety, enhancing system availability and scalability. Precision smart battery management technology further boosts constant power output across the full SOC range.
Development of Power Modules and Control Chips for Grid-Forming Energy Storage: This innovation achieves transient high-rate active and reactive power support and introduces a novel anti-moisture transfer molding technology, ensuring long-term reliable operation in harsh environments. It also establishes a robust capability system for the design and manufacturing of core underlying components.
Securing Innovation Leadership
Through continuous testing, Huawei has discovered that grid-forming technology not only enhances the stability of power systems but also offers significant multi-scenario deployment value. On the generation side, for clean energy bases and weak-grid renewable energy access areas, it greatly enhances the active support capabilities of renewable energy plants, facilitating higher renewable energy grid penetration. On the grid side, it bolsters flexible adjustment and reliable operation for ultra-high-voltage transmission endpoints and load centers with hollowed-out generation capacity. On the consumption side, it enables 100% renewable energy grids and on/off-grid power supply in end-user scenarios such as microgrids, highlands, mining areas, and islands.
In-depth research on the safety and stability of renewable energy grid integration has paved the way for Huawei to launch projects across multiple domestic and international scenarios.
Domestically, Huawei has collaborated with power grid and generation enterprises to advance grid-forming energy storage projects, conducting comprehensive, multi-condition tests in places like Qinghai. These projects have achieved satisfactory results in testing comprehensiveness, scale, and performance metrics, completing over 2,300 test items covering unit-level, station-level, regional grid simulation, and off-grid scenarios.
Internationally, the first phase of Saudi Arabia's Red Sea New City project, featuring a 400 MW solar PV plant and 1.3 GWh energy storage system, has adopted Huawei's string inverters and smart string-based grid-forming energy storage solutions. Fully operational since September 2023, the project has supplied over 1 billion kWh of green electricity and stands as the world's first microgrid powered entirely by renewable energy. The project has successfully demonstrated key grid-forming technologies such as the synchronization of 1,000 PCS units, minute-scale black start over hundreds of kilometers, resistance to 100% transformer switching impact, and zero-voltage fault ride-through in off-grid mode.
As the penetration of renewable energy continues to rise and more power electronic devices are connected, challenges such as randomness, high volatility, low inertia, intermittency, and weak support in power systems will become increasingly prominent. Against this backdrop, grid-forming energy storage is set to become a mainstream trend and a strategic technological frontier in power system innovation.
