In our previous article, we introduced the fundamentals of G99 certification, including its scope, applicability, and significance.
In this article, we will take a deeper dive into the key technical requirements, compliance testing, certification process, and timeline. We will also explore the characteristics of a G99-certified battery energy storage system (BESS) and how these features ensure safe and reliable grid integration in the UK.
1. Key Technical Requirements of G99 Certification
To ensure the safe and stable integration of energy storage systems into the UK grid, the G99 standard outlines several technical requirements, including:
- Dynamic Frequency Response (DFR) – The system must be capable of quickly responding to fluctuations in grid frequency. If the grid frequency rises or falls, the BESS should adjust its power output within milliseconds to maintain stability.
- Anti-Islanding Protection – Prevents the storage system from continuing to supply power to local loads when the main grid is down, ensuring safe reconnection when grid power is restored.
- Power Quality Standards:
- Limits on harmonic distortion to prevent power pollution in the grid.
- Voltage fluctuation control to avoid abrupt voltage variations caused by system operation.
- Reactive power regulation to support voltage stability within the network.
- Fault Ride-Through (FRT) Capability – The system must remain operational during short-term grid disturbances, such as voltage sags, and quickly resume normal operation once the grid recovers.
- Remote Monitoring and Control – The system should support real-time remote control, allowing grid operators to adjust power output, voltage, and frequency dynamically to enhance grid flexibility.
2. Key Compliance Tests for G99 Certification
To achieve G99 compliance, battery energy storage systems must undergo rigorous testing to ensure they meet the required standards. The key compliance tests include:
- Grid Compatibility Testing – Evaluate how well the storage system integrates with the grid under different operating conditions, such as power adjustments, on-grid/off-grid switching, and frequency response.
- Safety Testing – Assesses system protections, including short-circuit protection, overload protection, and overvoltage/undervoltage safeguards, to ensure the system does not pose risks to the grid.
- Disturbance Immunity Testing- Examines the system’s stability under grid disturbances, such as voltage dips or frequency fluctuations. Tests how well the system recovers from extreme operating conditions.
- Functionality Testing: Evaluates dynamic power adjustment capabilities, including active and reactive power regulation. Assesses grid support functions, such as reactive power compensation and peak shaving.
- Black Start Capability Testing – Determines whether the storage system can autonomously restart and supply power to critical loads in the event of a total grid blackout.
3. G99 Certification Process and Timeline
The G99 certification process typically involves the following steps:
- Preliminary Preparation – The manufacturer ensures that the energy storage system design aligns with G99 technical standards.
- Third-Party Testing and Evaluation – An independent certification body conducts laboratory and on-site testing to assess system performance under various conditions.
- Compliance Reporting and Approval – Once testing is complete, the manufacturer submits test reports and documentation for review by grid operators or regulatory bodies.
- Final Certification and Grid Connection – Upon approval, the system receives G99 certification and is authorized for grid integration.
- Certification Timeline – The entire process usually takes between 3 to 6 months, depending on system complexity, testing progress, and approval procedures.
4. What Are the Characteristics of a G99-Certified Energy Storage System?
A G99-certified energy storage system not only meets the regulatory requirements for grid connection but also offers the following advantages:
- High Reliability – The system undergoes rigorous safety and stability testing, ensuring long-term operational reliability and reducing the risk of grid disturbances.
- Enhanced Grid Adaptability – Features such as dynamic frequency response, reactive power regulation, and black start capability make the system more adaptable to the operational needs of the UK grid.
- Advanced Monitoring and Control – Remote monitoring and intelligent scheduling allow grid operators to optimize system performance and enhance overall grid stability.
- Regulatory Compliance and Market Access – G99 certification ensures seamless entry into the UK market, preventing connection refusals or legal risks associated with non-compliant systems.
- Lower Operational Costs – Optimized power regulation and grid adaptability minimize equipment wear and tear, leading to reduced long-term maintenance costs.
SCU’s Technical Advantages:
- SCU’s energy storage systems have successfully passed G99 certification, offering high stability, efficiency, and intelligent operational capabilities.
- Our systems incorporate advanced Energy Management Systems (EMS) to optimize performance across diverse applications.
5. Future Outlook
Potential Future Changes to the G99 Standard
- Stricter grid compatibility requirements, including more precise frequency regulation and faster response times.
- Enhanced cybersecurity measures for remote control and data security.
- Increased adoption of smart grid interaction capabilities, such as Virtual Synchronous Generator (VSG) technology.
6. Conclusion
SCU remains committed to delivering fully compliant energy storage solutions that support seamless grid integration while maintaining the highest standards of safety and performance. Moving forward, we will continue to monitor updates to G99 and other international standards to provide cutting-edge storage technologies to global markets.
Stay tuned for our other certification science series articles where we will explore other series-related certification information and the practical application of the G99-certified energy storage products!