How Green is Your Energy

Electricity suppliers must disclose to their customers the mix of fuels used to generate the electricity supplied to them annually.

All suppliers licensed in Ireland have to present information on the electricity that they supply to their customers on their bills to allow them to make an informed choice on the sources of their electricity. Suppliers have to do this within two months of the annual publication of the CRU’s Fuel Mix Disclosure information paper.

Fuel Mix Disclosure

Fuel Mix Disclosure (FMD) differentiates suppliers, enabling the consumer to choose the supplier that best fits their environmental expectations.

FMDs present reliable and verifiable information regarding the sources of electricity that suppliers use to meet their customers’ electricity needs and the related environmental impact. It does this by disclosing the fuel mix as the percentage of a supplier’s demand that is met by various electricity sources and the intensity of the associated carbon dioxide (CO2) emissions (grams/kWh).

The fuel mix and CO2 emissions disclosures allow consumers to understand the recent environmental impact of the electricity that they buy and to choose between suppliers on this basis, compared with the All-Island (Ireland and Northern Ireland) average.

The FMD is included on bills and promotional materials issued to customers.

The Single Electricity Market Operator (SEMO) carries out calculations on FMD on a calendar year basis on behalf of the CRU. The CRU then publishes CO2 emissions intensity data for each supplier.

Verification of the data which forms the basis of each supplier’s FMD is carried out independently, so Irish consumers can be confident about the validity of the published FMD figures for individual supply companies.

More information on the Fuel Mix Disclosure.

Guarantees of Origin

A Guarantee of Origin (GO) is an electronic document which provides proof to a final customer that a given share or quantity of energy was produced from renewable sources.

It is essentially a "green label" giving the electricity customer a guarantee that the electricity is generated from renewable sources. Each GO unit represents one megawatt hour (MWh) of generated electricity.

GOs are tradable across the EU, as required by EU law. They are tradable instruments and do not need to follow the flow of energy. GOs can be both exported from Single Electricity Market (SEM) and imported to SEM to/from the rest of the EU.

To supplement the electricity which they have sourced in Ireland, Irish electricity suppliers can buy additional GOs to certify that a greater share of their electricity demand is covered by renewable sources, i.e., verified green electricity supply in Ireland can be sourced from electricity physically produced in other EU countries. This means that the fuel mix shown by suppliers in Ireland can have a higher percentage share of renewable energy sources than exists in the actual physical generation distributed to end customers via the grid in Ireland.

SEMO is the nominated Issuing Body for GOs in Ireland. Every year, electricity suppliers in Ireland submit a fuel mix declaration form to SEMO, which performs the fuel mix calculation in accordance with a regulatory framework established by the CRU.

SEMO are also a member of the Association of Issuing Bodies (AIB) which facilitates the international exchange of Guarantees of Origin via the inter-registry telecommunications hub (AIB hub). AIB also ensures that electricity tracking does not lead to double counting. The AIB hub allows suppliers to purchase (or sell) the renewable benefit of certain generators across Europe and include it in their total fuel mix.

Green Source Product Verification (GSPV)

A supplier in Ireland whose average overall fuel mix is not 100% renewable can still offer Green Source electricity products to its consumers. In these cases, the CRU’s Green Source Product Verification (GSPV) process, helps to ensure that such supply companies source enough electricity from renewables and GO credentials to meet the entire demand which corresponds to these Green Source products.

Electricity suppliers in Ireland offering green products, which do not have an annual FMD of 100% renewable fuel sources, have to liaise with SEMO who will advise them of what is required to have their green source product verified. Those suppliers who have proved that their electricity as sourced 100% from renewable sources through the FMD are exempt from the GSPV process as they have already proved (through appropriate checks) their “green” claims.

For further information or queries relating the FMD, GOs or GSPV, please contact us at