Irish and Danish electricity suppliers have recently tested the use of granular guarantees of origin (GOOs), matching production and consumption on an hourly basis. But as concerns about grid balance remain among participants in the wider European GOO market, a gradual approach might be key.
Software provider Granular Energy this week announced the results of a pilot with Irish suppliers Electric Ireland, Flogas and SSE Airtricity and GOO registry provider Grexel — part of EEX group. This aimed to test a "hybrid system", in which hourly matched GOOs are used alongside less granular certificates.
Participating suppliers received hourly GOOs for output from selected renewables assets, and cancelled them on behalf of users for their April 2025 consumption. Granular Energy acted as the issuing body, while Grexel provided a "sandbox version" of the national GOO registry, enabling the coexistence of certificates at different levels of granularity.
One of the key findings of the study was that "allowing a phased, opt-in rollout" can help reduce overall data volumes and preserve compatibility with the rest of the Association of Issuing Bodies (AIB) hub, according to Granular Energy. "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," Granular Energy co-founder and chief operating officer Bruno Menu said.
The pilot follows a late-2024 report by the Sustainable Energy Authority of Ireland that recommended an upgrade of the national GOO system to enhance emissions reporting for "large energy users", such as data centres.
Grexel has recently been awarded funds to help interested GOO issuing bodies develop hourly tracking infrastructure.
Meanwhile, Danish electricity supplier Reel also recently completed a pilot with Granular Energy and national transmission system operator Energinet, with the results announced at the end of June. As part of this, five Danish companies matched their electricity consumption to GOOs on an hourly, weekly and monthly basis.
Wider push
The 24/7 Carbon-Free Coalition — part of international non-profit Climate Group — in June released its first technical criteria for companies claiming to use carbon-free electricity (CFE) globally, recommending the use of hourly matching for all claims based on certificates.
In addition to that, standard-setting group Greenhouse Gas Protocol has been conducting a review of its reporting standards. Based on initial feedback, the technical group working on scope 2 emissions — covering indirect emissions from purchased energy — is updating inventory rules with greater granularity, with a public consultation to be launched later this year.
A fine balance
Some GOO market participants are concerned about 24/7 CFE matching creating a new system of incentives that could ignore the needs of the wider electricity network, where consumption and production must be balanced at all times.
In a 24/7 CFE system, players could make decisions based on their contracted renewable assets, rather than respond to real-time signals from the grid, independent originator Axel Baudson told Argus. For example, power oversupply "on a beautiful sunny afternoon" — when renewables production is high — could increase if renewables generators are contractually obliged to deliver hourly matched certificates, he explained. For this reason, granular matching should be expanded "with a perspective of dynamic grid balancing", Baudson said.
These "suboptimal" scenarios are minimised "once a larger pool of consumers and producers is involved", Granular Energy's Menu told Argus in response, explaining that the ultimate aim is to move from individual corporate strategies for procuring granular GOOs to "a broader optimisation at the country level". This creates price signals and drives better alignment with the needs of the grid, he added.
Under the annual disclosure regime — the most common across European countries — consumption can be matched to output at any point during the disclosure year to reach zero emissions. This is often not possible when first moving to hourly disclosure, Menu explained, because of the reality of physical power flows during the day. This, in turn, creates more incentives to decarbonise the wider grid and invest in storage capacity.
Annually (mis)matched
Even within the current annual system, disclosure rules and certificates' expiry periods differ across European countries. Some national registries allow GOO cancellations for 12 months from the energy production, while others extend this to 18 months.
A harmonised framework for annual disclosure should be the priority, several GOO traders told Argus, before gradually adopting more specific timeframes, such as quarterly and monthly.
France has the most granular disclosure system in the AIB hub, requiring monthly matching, with certificates typically commanding a premium to Europe-wide contracts. Current-year French GOOs from solar, wind and hydropower traded at an average of €0.93/MWh at the end of June, above average Argus assessments of €0.74/MWh for 2025 European wind and solar and Nordic hydro GOOs.
