Granular Energy, Grexel, Electric Ireland, Flogas, Airtricity pave the way for hourly Guarantees of Origin in Ireland

Ireland just took a significant step towards more transparent and precise electricity emissions reporting. Granular Energy, with partners Grexel, Electric Ireland, Flogas, and SSE Airtricity, has successfully completed a pilot testing hourly Guarantees of Origin (GOs) in Ireland.

The results are clear: implementing an hourly GO system alongside monthly GOs is technically and operationally feasible.

A need for greater precision

As Ireland works toward its 2050 net-zero target, the increasing electricity consumption of Large Energy Users (LEUs) poses a significant challenge. By 2032, LEUs are projected to account for at least 30% of electricity consumption in Ireland. For such energy-intensive sectors, emissions reporting needs to evolve beyond annual matching.

The Sustainable Energy Authority of Ireland (SEAI), under direction from the Department of Climate, Energy and the Environment, outlined this need in a 2024 report recommending the introduction of hourly time-stamped electricity certificates. These certificates would allow LEUs to prove that their electricity usage is matched with carbon-free generation on an hourly basis.

Pilot testing clarifies hourly GO implementation

Following the publication of SEAI’s report, Granular Energy launched this pilot to test the feasibility of hourly GOs and clarify stakeholder roles and implementation options. Supported by the Granular Energy platform and an hourly-enhanced sandbox environment of the Grexel G-REX registry, participating suppliers received test hourly GOs for selected renewable production assets, then matched and cancelled them against customer consumption data on an hourly basis over April 2025.

“Granularity has been discussed in the market for some time now and it’s important for us as registry provider to understand how it can evolve further,” says Markus Klimscheffskij, CEO of Grexel.

The pilot successfully tested a concurrent hourly and monthly GO system within a single registry which would facilitate a phased, opt-in rollout for early adopters, if implemented that way. The decision to implement hourly GOs now rests with the Department of Climate, Energy and the Environment. With DCEE’s support, Ireland can take a decisive step toward more transparent, dynamic, and credible electricity emissions reporting, delivering on the ambition set out in the Climate Action Plan. For the complete insights, read the full report.

“We’re glad to see strong market support for optional hourly GOs alongside monthly ones” said Bruno Menu, Granular Energy cofounder and COO. “This kind of optionality creates a clear path for Ireland and EU Member states to gradually transition to hourly systems independent of an EU-wide overhaul.”