Solar Panels Mayo — Costs, Grants and Local Installers in 2026

A 4 kWp solar panel system in Mayo costs between €8,000 and €10,500 installed, or roughly €6,200–€8,700 after the SEAI Solar Electricity Grant of up to €1,800. Mayo has 45 SEAI-registered solar installers active as of May 2026 — enough for competitive quotes across the county, including rural areas. Payback on a well-sited Mayo system typically runs 8–11 years, reflecting the county's Atlantic-coast irradiance levels, which are lower than the southeast but still produce a meaningful return across a 25-year panel lifespan.

Mayo's irradiance averages 900–950 kWh/m² per year — honest mid-table for Ireland, well above what many people assume for the west coast. The county's large rural footprint, mix of working farms, and growing number of remote workers with high daytime electricity use all mean solar makes practical sense here, even if the headline yield figures don't match Cork or Wexford. The same SEAI grant rules apply in Mayo as everywhere else, and your installer must be on the SEAI registered companies list at mgen.seai.ie/register.

Solar Panel Costs in Mayo — 2026

Typical installed costs for Mayo residential systems, May 2026. Gross figures cover supply, installation, inverter and commissioning on a standard south- or southwest-facing roof. After-grant figures apply the full SEAI Solar Electricity Grant. Annual savings assume 30% self-consumption at a blended rate of 28c/kWh plus Clean Export Guarantee payments — your actual figure depends on when you use electricity and what your supplier pays for exports.

The SEAI grant is capped at €1,800 regardless of system size. A 3 kWp system attracts €1,600; anything 4 kWp or above attracts the maximum €1,800. Adding a battery typically adds €2,500–€4,500 to the gross cost and is not currently covered by the SEAI Solar Electricity Grant. For a full breakdown of system size, costs and payback across Ireland, see our solar panels cost Ireland guide.

Note on Mayo pricing: Mayo is a large county and rural site visits take time. Some installers charge a call-out fee for very remote locations; most do not. Ask when requesting a quote. The ranges above reflect standard residential installs — farm-scale systems are priced separately and are not covered by the SEAI Solar Electricity Grant.

How Much Electricity Will Solar Generate in Mayo?

Mayo averages 900–950 kWh/m² of solar irradiance per year — lower than the southeast (Cork and Wexford sit at 1,050–1,100 kWh/m²) but not dramatically so. The difference between a south-Mayo roof and a Cork roof is roughly 100–150 kWh per kWp per year. On a 4 kWp system that is 400–600 kWh annually — real, but not the gap that justifies ruling out solar entirely.

What matters more than irradiance is roof orientation and shading. A south-facing Mayo roof with no shading will outperform a heavily shaded south-facing Cork roof on every metric that matters. The Atlantic coast also gets high levels of diffuse light — the sky is bright even when the sun is not directly visible, and modern panels respond to diffuse light, not just direct sun. A Mayo system will produce meaningfully on an overcast day, even if it produces less than on a clear summer day in Wexford.

For a well-sited Mayo system — south- to southwest-facing, 30–40 degree pitch, minimal shading — expected annual generation is:

A typical Irish home uses 4,200 kWh per year. A 4 kWp Mayo system generating 2,900–3,400 kWh covers roughly 70–80% of that total — but only if consumption and generation align. Electricity consumed directly from the panels (self-consumption) saves you the full import rate, currently around 28–33c/kWh depending on your tariff. Electricity exported earns you the Clean Export Guarantee rate — rates are set by individual suppliers, not by government. Energia and Bord Gáis were paying 18.5c/kWh as of early 2026; check your supplier's current rate before relying on a specific figure. The self-consumption portion is worth significantly more per kWh, so homes with daytime electricity use (remote workers, heat pumps running during the day, EV charging on a timer) see faster payback.

The SEAI Solar Electricity Grant in Mayo

The SEAI Solar Electricity Grant is a national scheme administered by the Sustainable Energy Authority of Ireland (seai.ie). The rules and grant amounts are the same in Mayo as in every other county.

Grant tiers (verified against seai.ie, May 2026)

• First 2 kWp: €700 per kWp (€1,400 for 2 kWp)
• Next 2 kWp: €200 per kWp
• Maximum: €1,800 (reached at 4 kWp and above)

A 3 kWp system attracts €1,600 in grant support. A 4 kWp or larger system attracts the maximum €1,800. The grant does not scale above 4 kWp — installing a 6 kWp system returns the same €1,800 as a 4 kWp system.

Eligibility conditions

• Your home must have been built and occupied before 2021 (SEAI's exact wording).
• A post-works Building Energy Rating (BER) assessment must be carried out after installation — this is a condition of drawing down the grant, not an eligibility filter. There is no minimum BER rating required and no requirement for a BER to exist before you apply. The old B2 threshold was removed in 2022.
• The installer must be on the SEAI registered companies list at the time the work is carried out. You can search the register at mgen.seai.ie/register. A company that was previously registered but has since lapsed cannot process your grant.
• The grant applies to new solar PV installations only. Replacing or upgrading an existing system does not qualify.
• SEAI does not specify a primary residence requirement — the grant is open to all homeowners, including private landlords and owner management companies. Holiday homes are not explicitly excluded in SEAI's published rules. That said, SEAI applies judgment in individual cases and the scheme is designed for owner-occupied and rented residential properties. If you are applying for a holiday home in Mayo, contact SEAI directly at solarpv@seai.ie to confirm eligibility before proceeding.

How the grant is paid

You must apply and receive a Letter of Offer from SEAI before any works begin. Apply at mgen.seai.ie. Starting work before the offer is issued means you will not receive the grant.

Once you have your Letter of Offer, you have 8 months to complete the installation and submit all documentation. You pay the installer the full invoice amount. Once installation is complete and the required documents are submitted — Declaration of Works, Safe Electric certificate, NC6 grid connection form, post-works BER — SEAI transfers the grant directly to your bank account. The grant is not deducted at point of sale; you pay in full and receive the grant separately. SEAI states 4–6 weeks to process payment once all documents are received. For the full eligibility rules and step-by-step application process, see our SEAI solar grant guide.

Rural Mayo: Installers, Site Visits, and Farm Solar

Mayo is one of Ireland's largest and most rural counties. Castlebar is the county town; Ballina, Westport, Claremorris, and Ballyhaunis are the main service centres. Much of the county's population lives outside these towns, in areas where getting three competitive quotes used to mean several weeks of chasing. That has changed with 45 SEAI-registered installers now covering the county.

Most Mayo installers offer free site visits. For homes in genuinely remote areas — Achill Island, the Erris peninsula, the Nephin Beg range foothills — it is worth confirming upfront whether a call-out applies. The minority that do charge typically credit it against the installation cost if you proceed. Quotes based on a satellite or aerial survey alone, without a physical roof inspection, are worth treating with caution — ridge-and-hip roof configurations common in older Mayo homes need accurate measurement before a system size is confirmed.

Farm solar in Mayo — what TAMS covers

If you are farming in Mayo, the SEAI residential grant does not apply to agricultural buildings. Farm solar falls under TAMS (Targeted Agricultural Modernisation Scheme), administered by the Department of Agriculture, Food and the Marine. TAMS provides grant support for on-farm solar PV installations for own-use electricity generation — reducing diesel and grid consumption for milking, lighting, ventilation, and other farm loads. The grant rate and eligible costs differ from the SEAI residential scheme, and TAMS applications go through the Department's agfood.ie portal, not through SEAI.

Mayo's significant beef and sheep farming sector, combined with the county's rural spread and rising electricity costs, makes on-farm solar a practical option for many holdings. A farm system is sized to the actual electricity consumption of the buildings, not to a notional 4 kWp standard — correct sizing requires a 12-month electricity consumption analysis. Any installer quoting a farm system without requesting meter data is guessing.

Commercial solar for farm diversification — selling electricity to the grid rather than for own use — falls under a separate framework and is outside the scope of this guide.

Planning Permission for Solar Panels in Mayo

Most residential rooftop solar installations in Mayo do not require planning permission. Under the Planning and Development Act 2000 (Exempted Development) (No. 3) Regulations 2022 (SI 493/2022), rooftop solar panels on a house are exempt from planning permission within standard size and height limits. The full statutory instrument is published at irishstatutebook.ie.

Exceptions apply to protected structures, properties in architectural conservation areas, and some flat-roof configurations. Ground-mounted systems are subject to more restrictive rules and are not covered by the same exemption. If your home is a protected structure or is within an architectural conservation area, contact Mayo County Council's planning department before proceeding.

Your installer should confirm planning exemption status before contracts are signed. For a standard detached or semi-detached house on a pitched roof in Mayo, the exemption almost always applies.