RESS 6 Terms and Conditions Published: What It Means for Solar and What Comes Next
By Leanne Donovan, Policy Manager, Solar Ireland
The Government has now published the final Terms and Conditions for the sixth Renewable Electricity Support Scheme (RESS 6) auction.
Following the consultation process earlier this year, the final Terms and Conditions provide greater certainty for project developers preparing to participate in Ireland’s first RESS auction to incorporate the new Net-Zero Industry Act (NZIA) requirements.
RESS 6 represents one of the most significant developments in the scheme since its introduction, bringing substantial changes to the framework under which solar projects will compete. Throughout the consultation process, Solar Ireland worked closely with its members and submitted a comprehensive response representing the interests and experience of the wider solar sector.
This update outlines what the final Terms and Conditions mean for solar, highlighting the key changes, where the Government has adopted Solar Ireland’s recommendations, and what comes next.
What Is Included in the Final Terms and Conditions?
1. Technology-Specific Auction Pots
The Department of Climate, Energy and the Environment put forward two options for consultation, Options 4 and 5. Solar Ireland recommended Option 4 as the most appropriate approach for introducing the new NZIA non-price criteria.
The Department has adopted this approach, meaning RESS 6 will operate with separate technology-specific auction pots for solar and onshore wind. Within each pot, projects will be scored based on 85% price, 5% resilience and 10% energy system integration.
This also addresses Solar Ireland’s concern that technologies with different cost structures and supply chains should not compete under a single auction framework.
2. Energy System Integration
The energy system integration score allocates up to 2.5% for incorporating a secondary technology and 7.5% for battery storage, signalling the Government’s intention to encourage more flexible and integrated renewable energy projects.
Recent developments, including the publication of the Maximum Export Capacity Sharing Decision, are welcome steps towards enabling the development of hybrid solar and storage projects.
However, important regulatory and market barriers remain. Current rules continue to limit the efficient deployment of hybrid and co-located projects, meaning developers are being incentivised through RESS to deliver capabilities that the wider regulatory framework does not yet fully support.
Addressing these barriers will be critical to ensuring that the energy system integration criteria achieve their intended objectives.
3. Solar Capacity Factor Remains Unchanged
One of Solar Ireland’s key recommendations was that the solar capacity factor should remain at 11%, reflecting actual operating experience across Irish solar farms, rather than increasing to the proposed 14%.
The Department has accepted this recommendation, providing a more realistic basis for solar projects preparing to participate in the auction.
4. Unrealised Available Energy Compensation
The existing Unrealised Available Energy Compensation provisions have been retained, reflecting Solar Ireland’s recommendation that it is too early to remove or reduce the mechanism while barriers to hybrid and storage project deployment and dispatch down remain unresolved.
“The RESS 6 auction will be a significant milestone for the solar sector. We’re pleased that many of Solar Ireland’s recommendations have been reflected in the final Terms & Conditions, providing greater certainty for the solar industry as it prepares for the next auction. Looking ahead, the focus must be on ensuring the wider policy and regulatory framework keeps pace, particularly for hybrid and storage projects, so that future RESS auctions continue to drive investment, lower costs for consumers and accelerate renewable energy deployment.” – Leanne Donovan
Next Steps
With the publication of the final RESS 6 Terms and Conditions, the Department and EirGrid, as auction administrator, have confirmed the RESS 6 auction timetable.
Organisations intending to participate should note the following key milestones:
- Qualification window: 30 July to 27 August 2026
- Final qualification decisions: 21 October 2026
- Auction submission window: 29 October to 5 November 2026
- Provisional auction results: 18 November 2026
- Final auction results: 2 December 2026
- Notices of Award: 10 December 2026
Solar Ireland will continue to engage with the solar industry and key stakeholders as RESS 6 progresses. Following the completion of the auction, we will assess its outcomes and identify opportunities to improve future auction rounds, while continuing to advocate for the reforms needed to support the continued growth and delivery of solar projects across Ireland.