Understanding G98 and G99 Certificates

G98 and G99 certificates are key paperwork required to ensure your system complies with local regulations. A G98 certificate is needed for small-scale installations (up to 16A per phase), such as most home solar panels and batteries.
For larger systems, or those connecting to three-phase supply, a G99 certificate is required. These certificates confirm that your system meets national standards and can safely connect to the electricity grid.

Before granting permission, your local Distribution Network Operator (DNO) may place limitations on your installation.
Common restrictions include the maximum capacity you can export to the grid, technical requirements for grid protection, or even refusal if the local network cannot handle the extra generation. You may be asked to upgrade your connection, install export limiting devices, or provide detailed specifications to prove compliance.
Sometimes, the DNO will insist on an engineering study to assess potential grid impacts. Gaining DNO approval and the correct certification is vital before installation begins, ensuring your system operates safely and legally within UK regulations.

For your piece of mind the Renewable Energy Service experts will take care of all elements your certification, clearly explaining any limitations before your installation goes ahead.