Decarbonised electricity system study

SEAI is leading a multi-year study to explore pathways to eliminate greenhouse gas emissions from the Irish electricity system and the economic impacts of doing so.

Introduction

The 2023 Climate Action Plan sets a target of meeting 80% of electricity demand from renewable sources by 2030. Beyond this, a pathway to eliminate greenhouse gas emissions from the electricity system in Ireland has yet to be defined. The Department of Environment, Climate and Communications has asked SEAI to lead on developing an evidence-based pathway, or choice of robust alternative pathways, for decarbonising the Irish electricity system after 2030. SEAI will develop the pathway based on rigorous research and engaging with a wide cohort of stakeholders to build consensus.

Work plan

There are multiple stages to this study, with outputs scheduled between 2024 and the end of 2026. Broadly, the study will progress as follows:

Assess electricity generation, storage and services technologies for inclusion in power sector portfolios based on their performance against economic, technical, environmental and social criteria in the Irish context.
Develop power sector technology portfolios weighted to achieve strategic national and public priorities as inputs to techno-economic modelling.
Assess the direct electricity system impacts, and coupled energy sector impacts, of different decarbonisation scenarios.
Quantify the total investment and operational cost of pursuing alternative power sector decarbonisation pathways, and the economic impacts on the electricity market and consumers.

Stakeholder engagement

Extensive cooperation with diverse stakeholders is key to success. SEAI convenes a stakeholder engagement process to inform the technical work. In Q4 2023, we commenced this process by establishing a Working Group to direct and critique the initial work. This group serves as a first tier for scoping the programme of work, and legitimating the research objectives, decisions and methods within key state agencies, including the Department for Climate, Environment and Environment (DCEE), the system operators (Eirgrid, ESB Networks, and GNI), the Commission for Regulation of Utilities (CRU), the National Treasury Management Agency, and the National Economic and Social Council (NESC).

In Q3 2025, SEAI established a Stakeholder Forum to incorporate the views of a wide range of stakeholders, both within the power sector and closely related sectors affected by the decarbonization of the power sector. Forum meetings will largely consist of thematic or problem-based workshops to resolve underpinning issues where specialist judgement or data is needed to progress analysis.

Further information:

DESS launch: presentations deck

DESS Launch: Recording - Session 1 of 2

DESS Launch: Recording - Session 2 of 2

Terms of Reference for the Stakeholder Forum

Open invitation for expressions of interest to serve on the Stakeholder Forum

Stakeholder Forum Meeting #1: presentation deck

Stakeholder Forum Meeting #1: Notes of Meeting (NOM)

DESS Frequently Asked Questions (FAQ): February 2026

Current Public Consultation: Technology Assessment Draft Results

Disclaimer: The draft report and Excel tool are provided for consultation purposes only. The draft findings are provisional, have not been peer reviewed, and should not be relied upon for policy, regulatory, investment, or operational decisions. Use of this information is at the reader’s own risk.

Context

SEAI has published the draft results of the DESS Technology Assessment for public consultation. The aim of the consultation is to gather stakeholder feedback on the evidence base that will underpin key DESS outputs. The Technology Assessment plays an instrumental part in the final outputs of DESS and related policy recommendations:

The input data for the Economic criteria will form part of the input data for the techno-economic modelling, which will determine the power sector portfolios for consideration
The technology deployment forecasts developed as part of the assessment will be used as constraints in modelling scenarios.
The input data for the Environmental and Irish Viability criteria, will be used to assess and compare modelled portfolios (the outputs of the techno-economic modelling) and inform policy recommendations on alternative sectorial pathways
The results of the assessment will inform provisional policy messages on the comparative performance of technology options for strategic national policy objectives.

Consultation process

The consultation opens on 18 December 2025 and closes on 23 February 2026 at 17:00.
All responses must be submitted via this online survey: https://forms.office.com/e/dPTqpWzabQ
- Every section and sub-field are optional.
- You will not be able to edit feedback after submitting, but you are able to navigate back and forth through the sections of the survey before submission. Your responses will not be automatically saved prior to clicking submit. We recommend saving responses in a separate document whilst work is in progress.
- If you have any challenge with accessing the survey, please contact the team by email at [email protected]

The consultation is structured around four components of the technology assessment, seeking comments on:

Technology screening: approach taken to screening technologies and the choice of 30 technologies
Assessment criteria: criteria used to assess technologies
Technology scores: data inputs used to assess and compare technologies
Assessment design: methods used to compare technologies
Any other feedback

Data Protection

We are committed to engaging with stakeholders in a clear, open and transparent manner. Any person or organisation can make a submission in relation to this consultation. We will consider all submissions in revising and publishing the final Technology Assessment.

Your response to this consultation is subject to the Freedom of Information Act 2014 (FOI); the Access to Information on the Environment Regulations 2007-2018 (AIE); the Data Protection Act 2018.

We intend to publish the contents of all submissions on this webpage as an appendix to the final report. We will redact personal data before publication.

In responding to this consultation, clearly indicate where your response contains any information which you would not wish to be released under FOI, AIE or otherwise published. This can include personal information, commercially sensitive information, or confidential information.

Outputs for consultation

The draft assessment outputs constitute a substantial piece of work (the “Technical Report”, “Excel Scoring Tool”, and appendices). We recommend navigating the outputs as follows:

To familiarise yourself with the study, start with the Technical Report, Sections 1 – 3 (Executive Summary, Introduction and Methodology)
For general review of the assessment criteria, refer to the Technical Report Section 4.1 – 4.5
To review criteria values and scores for technologies at a glance, refer to Section 5.1 of the Technical Report (by criterion) and the sheet “External criteria input” in the Excel Scoring Tool (by criterion and technology).
- For review of technology-specific values for quantitative criteria and the underpinning notes and sources, refer to the individual technology sheets in the Excel Scoring Tool and Appendix A – Documentation of Criteria Scores
- For review of the information input and sources for qualitative criteria scores (where the score is based on the pooled pairwise comparison scores from the subject matter experts), refer to Appendix A – Documentation of Criteria Scores and the rationalisation provided for each technology-criterion score.

Register your interest

If you would like to stay abreast of the Decarbonised Electricity System Study (DESS) through a quarterly newsletter or have any questions for the SEAI project management team, please complete the form here [ insert link: https://forms.office.com/e/gbkTPFXTUC ]

Register