Understanding UK Grid Regulations: G98, G99 and G100

UK Grid regulation G98 G99 and G100

Welcome to our blog, where we dive deep into the world of renewable energy installations. In today’s article, we’ll demystify the essential G98, G99, and G100 regulations governing renewable energy connections to the UK grid.

Understanding these regulations is crucial for a successful renewable installation, so let’s explore them in detail and guide you towards a seamless solar solution!

G98, G99, and G100

G98, G99, and G100 are engineering recommendations issued by the UK’s Office of Gas and Electricity Markets (Ofgem) and the Energy Networks Association (ENA). These regulations outline the technical requirements and safety standards for connecting solar PV systems to the grid.

G98: Unlocking Opportunities for Residential and Small-Scale Installations

G98 focuses on low-impact installations with capacities up to 16A per phase (3.68kW for single-phase and 11.04kW for three-phase systems). Perfect for residential properties and small businesses, G98 compliance ensures safe operation and network stability.

Key G98 Compliance Aspects

1) Meeting relevant standards, like IEC 62446, ensuring your renewable system meets all requirements.

2) Implementing essential protection devices, such as grid disconnect switches, to prevent exporting electricity during power outages.

3) You don’t need prior Distributed Network Operator (DNO) approval to connect renewable systems under G98. Once the renewable system is installed, send the commission letter.

G99: Empowering Commercial and Utility-Scale Projects:

G99 regulations cater to larger-scale renewable energy systems that surpass G98’s capacity limits. Ideal for commercial, industrial, or utility-scale projects, G99 compliance guarantees seamless integration and grid stability.

Key G99 Compliance Aspects

1) Conducting thorough studies and assessments to analyse the impact on the grid.

2) Implementing advanced protection systems, including specialised grid protection relays, to ensure stability and prevent issues like islanding.

3) You need prior Distributed Network Operator (DNO) approval by sending G99 A.1.1 to connect renewable systems under G99 regulation. Once you receive the DNO approval and the renewable system is installed, send the commission form, G99 A.3.1, to the DNO.

G100: Tackling the Challenges of Distributed Energy Resources

G100 addresses the rapid growth of distributed energy resources (DERs), such as solar PV, battery storage, and electric vehicle charging. Designed to manage high DER penetrations, G100 ensures efficient grid management and optimal power quality by imposing a renewable resource export limit based on network analysis.

Key G100 Compliance Aspects

1) Deploying advanced monitoring and control systems to manage DER impact on the grid.

2) Collaborating with local Distribution Network Operators (DNOs) for seamless DER integration.

3) Export limitation is implemented on renewable installation to prevent damage to the electrical network.

4) You are asked by the Distributed Network Operator (DNO) planner to send the G100- Export Limitation Scheme Application Form when you submit the initial G99 application. Once you receive the DNO approval and the renewable system is installed, send the G100 commission letter and G99 A.3.1 to the DNO.

Why are G98, G99, and G100 Essential for Your Solar Journey?

These regulations serve critical purposes, including:

Consumer Protection

Compliance with G98, G99, and G100 ensures the safe operation of renewable installations, protecting you and the grid operators. Adhering to these standards mitigates potential risks and maintains electricity network stability.

Grid Harmony

Following G98, G99, and G100, your renewable installation seamlessly integrates with the grid, contributing to overall stability and reliability. It avoids disruptions and imbalances that could impact the grid’s performance.

Future-Proof Solutions

These regulations evolve with technological advancements and changing energy landscapes. Complying with G98, G99, and G100 ensures your installation is future-proof, adaptable, and compatible with emerging grid requirements.


G98, G99, and G100 are the keys to a successful and seamless renewable installation. By understanding and complying with these regulations, you can embrace the abundant potential of solar/wind energy or battery storage while ensuring safety, grid stability, and future-proofing.

Seek guidance from Wing Energy, your experienced professionals who can navigate the requirements of G98, G99, and G100, and together, let’s embark on a solar journey that’s hassle-free and rewarding.

As we continue championing the transition to sustainable electrical energy, Wing Energy is your trusted partner on this journey toward a greener future. You can visit our website for the latest news and services on Solar PV, EV Chargers, and Battery Storage.

Contact us today for a non-obligatory solar and battery installation quote to be part of the sustainable energy revolution.

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