The G99 grid code was introduced in the UK in April 2019.
Understanding the G99 Grid Code Release
The G99 grid code, formally known as Engineering Recommendation G99, is a crucial set of regulations for connecting power generation equipment to the electricity network in the UK. Its introduction marked a significant update to how distributed generation, particularly from renewable energy sources, interacts with the National Grid.
Why Was G99 Introduced?
The primary reason for the implementation of G99 in April 2019 was to address the increasing proliferation of renewable energy generators connecting to the UK's National Grid. As more solar arrays, wind farms, and other sustainable power sources came online, there was a growing need for updated regulations to ensure the stability, safety, and efficiency of the electricity network.
The G99 grid code superseded the G59 grid code, which had been the standard for previous generations of power installations. This transition reflected the evolving landscape of energy generation and the imperative to modernize grid management practices.
Key Aspects of the G99 Code
The G99 code outlines the technical requirements for connecting various types of generating plants, including:
- Renewable Energy Systems: Such as solar PV (photovoltaic) systems, wind turbines, hydro schemes, and biomass generators.
- Combined Heat and Power (CHP) Units: Systems that generate both electricity and useful heat.
- Energy Storage Systems: Including battery storage, when connected in a manner that can export power to the grid.
These regulations ensure that new or modified power generation equipment:
- Maintains Grid Stability: By controlling voltage, frequency, and fault levels.
- Provides Grid Support: Including capabilities like active and reactive power control.
- Complies with Safety Standards: Protecting both the equipment and grid operators.
- Facilitates Seamless Integration: Allowing diverse energy sources to work harmoniously within the network.
Transition from G59 to G99
The transition from G59 to G99 was a phased process, allowing developers and installers time to adapt to the new requirements. Installations commissioned after the April 2019 effective date are required to comply with G99.
| Grid Code | Introduction Date | Primary Purpose | Predecessor |
|---|---|---|---|
| G99 | April 2019 | Regulating connection of diverse and growing renewable generation | G59 |
| G59 | Pre-April 2019 | Earlier standard for connecting generation equipment | N/A |
Importance for New Installations
For any new power generating equipment wishing to connect to the UK's electricity distribution network, compliance with G99 is mandatory. This involves:
- Detailed Application Process: Submitting specific technical data about the proposed generation.
- Commissioning Tests: Ensuring the equipment meets all required performance standards.
- Ongoing Compliance: Adhering to operational requirements throughout the lifetime of the installation.
The G99 code is vital for enabling a more decentralized and sustainable energy future in the UK, ensuring that as the energy mix shifts towards renewables, the grid remains robust and reliable.
