Grid Connection for Renewable Energy Projects
Grid connection can be one of the defining issues in a renewable energy project. This guide explains the basics of G98 and G99 applications, CLS and G100 export limitation schemes, and the electrical design work needed to support a successful connection.
Why Grid Connection Matters
A renewable energy project may be technically attractive on site, but the available network capacity and connection requirements often determine what can actually be installed.
Grid connection is the process of connecting generation equipment to the public electricity network so that power can be used on site and, where permitted, exported. For solar PV, wind turbines, hydro systems and battery storage, this is a fundamental part of project development.
In practice, grid connection is not just about whether a system can connect. It is also about how much export the network will allow, what protection and control measures are required, and what engineering documentation must be prepared to support the application.
For many projects, especially rural and commercial sites, the grid is the key constraint. This is why it is often sensible to review grid issues early rather than treating them as a late-stage formality.
G98 and G99 Applications
The applicable connection route depends on the type and size of the generation equipment and how it is intended to operate in parallel with the network.
In practical terms, G98 and G99 application support is not only about filling in forms. Good applications depend on clear system definition, correct equipment information, sound electrical design assumptions and coherent supporting documents.
For that reason, the quality of the technical submission often has a direct effect on how smoothly the connection process moves forward.
CLS and G100 Schemes
Where a site can generate more electricity than the network will accept, export limitation can allow the project to proceed within an agreed export cap.
A common situation on renewable energy sites is that the installed generation potential exceeds the export capacity that the network operator is prepared to allow. In these cases, the project may still be viable if export is actively limited.
Customer Limitation Schemes and G100 export limitation arrangements are closely related in practice. The site may be given an agreed export limit, and the export limitation system is then designed to ensure that net export remains at or below that figure.
This approach is particularly relevant where solar PV, wind, or hydro and battery storage are combined on the same site, or where on-site electrical demand varies significantly through the day or across the year.
Typical CLS / G100 work includes:
Review of the agreed export position for the site
Design of the export limitation strategy
Selection and arrangement of compliant control architecture
Preparation of supporting documents for the DNO
Integration of generation, metering and control functions
Export limitation is not simply a commercial preference. It is an engineering control strategy that must be designed properly if the site is to remain compliant with its connection agreement and network constraints.
Connection Design and Technical Documentation
Successful grid applications depend on more than the headline generator size. They also depend on clear electrical design and the right supporting engineering information.
SJ1 Renewables supports projects across the connection process, from G98 and G99 application preparation through to CLS and G100 export limitation design, electrical connection design and single line diagrams.
This is particularly important on constrained sites, hybrid renewable systems and projects where installed generation is intentionally greater than the export capacity the network will allow.
A Sensible Early-Stage Sequence
Early clarity on grid constraints can save time, reduce redesign and improve the quality of project decisions.
Step 1: Define the proposed renewable generation and site demand context.
Step 2: Review likely connection constraints and export objectives.
Step 3: Decide whether the project is a straightforward generation application or requires export limitation.
Step 4: Develop the electrical design basis and supporting drawings.
Step 5: Prepare and submit a clear technical application pack.
On many sites, the most important early question is not simply “how much can we generate?” but “how much can we connect, control and use within the agreed network position?”
Understanding Grid Constraints
Grid connection often defines what is possible on a site. Early-stage review helps identify constraints, risks and viable approaches.
Need Help With a G99, G100 or CLS Project?
SJ1 Renewables can support grid connection applications, export limitation scheme design, single line diagrams and wider electrical integration for renewable energy sites.