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Guarantees of Origin 

Guarantees of Origin (GOs) are electronic certificates issued for energy from renewable sources. GOs are issued to eligible Generators, for every 1 MWh of energy produced.

The sole purpose of GOs is for use in Fuel Mix Disclosure. For information on Fuel Mix Disclosure please click here.

As per Statutory Instrument no.147 of 2011, SEMO is named as the issuing body for GOs in Ireland. This scheme is for in-market (SEM) generators, out-of-market generators, and suppliers in Ireland.
The EU Directive (2009/28/EC) regarding GOs was transposed into law in Ireland, on the 28th of March 2011, by Statutory Instrument (S.I.) 147 of 2011. This S.I. named SEMO as the issuing body and the CER were required to set up a Supervisory Framework for GOs.
This Supervisory Framework was outlined in the Decision Paper CER/11/824 “Supervisory Framework for Administration of Guarantees of Origin”.

To view the frequently asked questions about Guarantees of Origin click here.

To find out more about Guarantees of Origin please contact the GO team at or call the Market Helpdesk (please refer to our contact us section for details).

SEMO is a joint venture between EirGrid PLC and SONI Limited