DG Connection Guide

Previously there were separate versions of the Guides. These separate versions have now been combined into the Distributed Generation Connection Guide: G98 & G99 which contains information applicable to all sizes of generation projects, including:

• EREC G98 compliant units in a single premises;
• EREC G98 compliant units in multiple premises within a close geographic region;
• EREC G99 Type A Power Generating Module projects; and
• EREC G99 Type B-D Power Generating Module projects.

Connecting Distributed Generation that falls under EREC G98 in a single or multiple premises

Distributed Generation is compliant with EREC G98 if:

• It meets the size definition of Micro-generator.
• It is installed in accordance with EREC G98. Your installer should be familiar with these requirements; and
• It has been tested and approved according to the relevant Type Testing Annex in EREC G98.

A Micro-generator is defined in EREC G98 as “A source of electrical energy and all associated interface equipment able to be connected to an electric circuit in a Low Voltage electrical installation and designed to operate in parallel with a public Low Voltage Distribution Network with nominal currents up to and including 16A per phase. For the avoidance of doubt this includes electricity storage devices”.

Connecting Type A Power Generating Modules under EREC G99

Installation of one or more Generating Units at a single premises where:

• The registered capacity of each Power Generating Module is >16 A/phase, but less than 1 MW; and
• The Connection Point is below 110 kV (in practice in GB this is at 66 kV or below).

Type tested equipment is defined in EREC G99 as “A product which has been tested to ensure that the design meets the relevant requirements of this EREC G99, and for which the Manufacturer has declared that all similar products supplied will be constructed to the same standards and will have the same performance”.

Connecting Type B — D Power Generating Modules under EREC G99

Installation of one or more Generating Units at a single premises where the registered capacity of each Power Generating Module is at or above 1MW, or for any generation connected at or above 110 kV (in practice in GB this is at 132 kV or above).

• Type B: Registered capacity from 1 MW to < 10 MW and connected at < 110 kV;
• Type C: Registered capacity from 10 MW to < 50 MW and connected at < 110 kV; and
• Type D: Registered capacity ≥ 50 MW or connected at ≥ 110 kV.

The Guide is intended to help you, as an owner or developer of Distributed Generation, to connect your generating plant to one of the UK's electricity distribution networks. A record of all revisions can be found at the rear of each guide. Please note that this is only a guide to EREC G98 and G99, not the actual technical engineering documents. Both engineering documents can be freely downloaded from the Distribution Code website.