As the demand for sustainable energy solutions continues to grow, Battery Energy Storage Systems (BESS) play a crucial role in enhancing grid stability, supporting renewable energy integration, and improving overall energy efficiency. However, connecting these energy storage systems to the UK electricity grid requires compliance with specific regulations to ensure safety and reliability. One of the most important standards for grid connection is G99 certification.
In this article, SCU will explore energy storage system G99 certification, why it is necessary, which systems require it, and its impact on energy storage enterprises.
1. What is BESS G99 Certification?
G99 is a technical standard established by the Energy Networks Association (ENA) that governs the connection of power generation equipment, including battery energy storage systems (BESS), to the UK electricity grid. Introduced in 2019, G99 provides a more comprehensive framework for integrating distributed energy resources safely and efficiently.
2. Why Is G99 Certification Required?
For BESS, compliance with G99 ensures that energy storage systems do not introduce instability, voltage fluctuations, or safety hazards that could disrupt grid operation. Whether a system is connected at low, medium, or high voltage levels, it must meet G99 requirements before being permitted to operate within the UK’s electricity infrastructure.
The certification ensures that BESS:
- Operates safely within the grid without causing voltage or frequency disruptions.
- Supports grid stability by responding dynamically to changes in power demand and supply.
- Prevents harmful effects, such as harmonic distortion and unintended islanding.
- Complies with UK regulatory requirements, ensuring legal operation and eligibility for grid services.
Without G99 approval, a system cannot be legally connected to the grid and risks being permanently disconnected.
3. Which Systems Require G99 Certification?
G99 applies to a wide range of energy generation and storage systems, including:
- Battery Energy Storage Systems (BESS) – for commercial, industrial, and utility-scale applications.
- Solar PV Systems – when integrated with storage or exceeding certain capacity thresholds.
- Wind, hydro, and other renewable generators – connecting to the UK’s distribution grid.
- Hybrid energy systems -that combine different generation and storage technologies.
The specific certification process and requirements depend on factors such as system size, capacity, and connection voltage level.
4. Is G99 Certification Mandatory?
Yes. BESS G99 certification is a legal requirement for any new distributed energy resource connecting to the UK grid. Failure to obtain G99 approval can result in serious consequences, including:
- Grid disconnection – The system may be permanently cut off from the electricity network.
- Operational risks – Uncertified systems may face unexpected failures or performance issues.
- Legal penalties – Non-compliant installations may be subject to regulatory action.
For businesses in the energy storage sector, ensuring full G99 compliance is essential to operate legally and avoid costly disruptions.
5. Impact of G99 Certification on Energy Storage Manufacturers
G99 certification has significant implications for energy storage companies like SCU, affecting areas such as market competitiveness, product development, and long-term strategy.
(1) Competitive Advantage in the UK Market
Achieving G99 certification allows SCU to expand its presence in the UK energy storage sector, providing compliant solutions to utilities, commercial clients, and renewable energy developers. Certification enhances credibility and trust among customers and stakeholders.
(2) Influence on Product Design and Cost
Technical Upgrades: Meeting G99 standards requires integrating advanced grid compliance features, such as dynamic frequency response and anti-islanding protection.
Increased Development Costs: Engineering, testing, and certification add to overall product costs, but also improve long-term reliability and performance.
Regulatory Adaptation: Future updates to G99 or related standards may necessitate continuous innovation in storage technologies.
(3) Future of the UK Energy Storage Market and Certification Trends
The UK government is promoting decarbonization and grid modernization, leading to higher demand for certified BESS solutions.
Potential updates to G99 may introduce stricter requirements, particularly regarding grid flexibility, cybersecurity, and data management.
Companies that proactively align with evolving standards will maintain a competitive edge in the market.
6. Conclusion: SCU’s Commitment to G99 Certification
As a leading energy storage system manufacturer, SCU recognizes the importance of G99 compliance in ensuring safe and efficient grid integration. We have successfully passed the certification and our energy storage systems have met the technical and safety standards of the UK market.
This means that SCU’s products can be put into use faster and provide stable and reliable energy storage solutions for customers in the UK and European markets. By meeting strict regulatory standards, SCU enhances its global reputation and strengthens its role in accelerating the energy transition.
For businesses and project developers looking to deploy battery storage in the UK, partnering with a G99-certified provider like SCU ensures regulatory compliance, reliability, and long-term success.
In the next article, we will analyze the main technical requirements and capacity of G99, key compliance tests, certification process and cycle in depth, so stay tuned!