Sharing of Maximum Export Capacity (MEC) behind a Single Connection Point - Outcomes

Closed3 Mar, 2025, 09:00 - 14 Apr, 2025, 17:30

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The consultation

The consultation, published on 3rd March 2025 and open until 14th April 2025, sought stakeholder views on a proposed policy that would allow multiple generation and/or storage technologies—such as wind, solar PV and battery storage—to dynamically share a single contracted MEC at a hybrid co‑located site. This proposal aimed to optimise the use of existing grid infrastructure, reduce connection timelines and costs, and accelerate the integration of renewable energy.

The CRU received 30 submissions from a broad cross‑section of industry, including developers, system operators, representative bodies, technology providers, academia and one private individual. Respondents provided detailed feedback across technical, operational, market and policy dimensions, addressing issues such as controllability, forecasting, metering requirements, market registration, Priority Dispatch interactions, and the future evolution of hybrid arrangements. This feedback directly informed the final decision.

Your views and suggestions

Stakeholders expressed broad support for enabling MEC sharing, recognising its potential to simplify hybrid project development, improve utilisation of existing grid infrastructure, and increase renewable output. Many respondents highlighted the benefits of combining technologies with complementary generation profiles, such as wind, solar and storage, to raise capacity factors and reduce dispatch‑down. At the same time, stakeholders identified a range of operational and market‑related issues, including the need for clear technical specifications, robust site‑level controls, accurate metering, reliable forecasting, and coordinated availability declarations. Several respondents raised concerns about interactions with Priority Dispatch, market registration, system services, and capacity market arrangements. Others noted that MEC sharing alone does not fully unlock hybrid potential and pointed to the future need for energy sharing and multiple legal entity arrangements. Overall, submissions were constructive and generally supportive, emphasising that successful implementation would require coherent updates across Grid and Distribution Codes, market rules, and operational processes.

Outcomes

The final decision on MEC sharing was developed following a detailed review of the System Operators’ (SOs) technical assessment, extensive feedback received through the public consultation and further engagement with the SOs. Stakeholder submissions helped inform key elements of the policy, including operational requirements and technical considerations for hybrid projects.

This evidence‑based process allowed the CRU to decide that the sharing of MEC at a single connection point shall be facilitated and CRU directed the SOs to proceed with the implementation of the decision.

In advance of the full implementation of this decision, the SOs are required to assess the existing rulesets, processes and codes, and update where necessary, to ensure that the sharing of MEC behind a connection point can be facilitated. A System Operator Implementation Roadmap is to be published by the SOs, which sets out the key activities and timelines required to progress implementation.

A summary of responses to the consultation and detailed assessment of those responses by CRU, along with the decision, is presented in Decision Paper CRU202643 (https://www.cru.ie/publications/29009/ )

Themes

Q1. Do stakeholders agree on the classification and the definition of hybrid co-located projects?
Q2. Do stakeholders believe that the sharing of MEC for co-located hybrid projects should be pursued ahead of integrated hybrid projects?
Q3. When do stakeholders foresee the need to facilitate integrated hybrid projects in the power system? Please provide rationale for your answer.
Q4. The CRU invites feedback from stakeholders on the benefits associated with the potential implementation of sharing of MEC. Is there a net benefit to the consumer in terms of costs and other potential benefits?
Q5. Are there any drawbacks associated with this proposal on MEC sharing? Please elaborate on the risks.
Q6. Do stakeholders support the proposal to allow for the sharing of MEC behind a single connection point for hybrid co-located projects? Will this facilitate additional renewable electricity production?
Q7. Do respondents foresee any difficulty with ensuring the export for a hybrid co-located project is limited to the MEC at all times?
Q8. Do participants envisage challenges with managing the interaction of different market and availability requirements (e.g. declarations of availability for active power and system services) at the connection point?
Q9. The CRU notes that this proposal does not facilitate energy sharing between units behind a connection point. However feedback is invited as to what measures may be required to address this and whether this can be addressed in ongoing workstreams.
Q10. Feedback is requested on whether there are risks associated with the sharing of MEC being applicable to all generation technologies.
Q11. Some of the changes needed in existing policies and processes are noted in Section 2.2. What are your views on these changes? Are there other changes in current processes needed to facilitate the sharing of MEC?
Q12. How can the associated control requirements (e.g. MEC limit at connection point) and mechanisms for sharing MEC be implemented?
Q13. Do respondents consider it feasible to submit software models that are an accurate representation of the total site and each of the Generator Units that are connecting behind the connection point prior to the connection of such hybrid units to grid?
Q14. Do respondents have concerns over potential unintended consequences on the SEM Energy Markets Capacity Market and System Services and if so how these can be prevented or mitigated?
Q15. Comments are sought on the predicted impacts on the system operations discussed under Section 2.2.10 and Appendix E.
Q16. Are there any other risks that should be considered as part of the decision-making process and how can these risks best be mitigated?
Q17. Do stakeholders believe that conducting a Pilot project is warranted to provide learnings in advance of full implementation of the sharing of MEC proposals?
Q18. Are there any additional considerations that should be taken into account in the formation of this policy?