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Planning Guide10 min read

When Does a Solar Farm in Ireland Need an EIAR?

Environmental Impact Assessment Reports (EIARs) are required for solar farms above certain thresholds in Ireland. Understanding these thresholds — and what an EIAR involves — is essential for project planning.

SolarPlan Ireland Team · Planning Consultants·14 November 2023

EIA Requirements for Solar Farms in Ireland

Environmental Impact Assessment (EIA) is a formal process for evaluating the environmental effects of certain types of development before planning permission is granted. When required, an EIAR must accompany the planning application.

The Thresholds

Under Schedule 5 of the Planning and Development Regulations 2001 (as amended), solar farms require EIA when they:

  • **Exceed 50 hectares** in site area; or
  • **Are in or adjacent to sensitive areas** (Natura 2000 sites, World Heritage Sites, etc.) and exceed 0.5 hectares
  • For projects below these thresholds, the competent authority (local authority or An Bord Pleanála) must carry out a screening determination to decide whether EIA is required on a case-by-case basis.

    What an EIAR Covers

    A full EIAR for a solar farm typically includes:

    1. **Population and human health** — impacts on nearby residents and workers

    2. **Biodiversity and ecology** — including Appropriate Assessment where Natura 2000 sites are involved

    3. **Land, soil, and geology** — soil disturbance, drainage, compaction

    4. **Water** — surface water and groundwater impacts

    5. **Air and climate** — construction dust, greenhouse gas calculations

    6. **Material assets** — infrastructure, land use, grid connection

    7. **Cultural heritage** — archaeology and built heritage

    8. **Landscape and visual** — the landscape chapter (Landscape Plan and photomontages)

    9. **Cumulative effects** — in combination with other projects

    10. **Interactions between the above** — often overlooked but important

    The EIAR Process Timeline

    Preparing an EIAR is a substantial undertaking:

  • **Scoping**: 4–8 weeks — agrees the scope and methodology with the competent authority
  • **Ecological surveys**: Up to 12 months (to capture seasonal variation in habitats and species)
  • **Specialist surveys**: 3–6 months (archaeology, hydrology, cultural heritage)
  • **Report preparation**: 6–12 weeks
  • **Total**: Plan for 18–24 months from instruction to submission for projects requiring full EIAR
  • Screening: When Is a Formal EIAR Required Below Thresholds?

    For solar farms between 5 and 50 hectares, a sub-threshold screening determination may be requested. The authority considers:

  • Size and location of the project
  • Nature and scale of emissions
  • Sensitivity of the receiving environment
  • Interaction with other projects
  • Our advice: commission an ecological screening report and cultural heritage desk study early. If sensitive receptors are identified, budget for EIA from the outset — it is far more costly to redesign or commission additional studies after submission.

    Contact Us

    SolarPlan Ireland coordinates multi-disciplinary EIA teams for solar projects. Contact us to discuss whether your project requires EIAR and to get a coordinated programme and cost estimate.

    EIAREIASolar FarmPlanning Ireland

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