A 5 kWp solar system costs €9,000–€11,500 installed in Ireland in 2026, or €7,200–€9,700 after the €1,800 SEAI grant. It generates roughly 4,000–4,500 kWh per year — enough to cover 90–107% of an average Irish home’s annual electricity use. Payback is typically 7–9 years post-grant. The 5 kWp size makes most sense if you have a heat pump, an EV charger, or higher-than-average electricity use. For a standard 3-bed home with no plans for either, the 4 kWp system is the grant-optimised choice.
5 kWp vs 4 kWp — Is the Extra Panel Worth It?
Most people searching for 5 kWp pricing are really trying to answer one question: is the extra panel worth it over the 4 kWp? Here is the maths most installers skip past.
The SEAI Solar Electricity Grant pays €700 per kWp for the first 2 kWp, then €200 per kWp for kWp 3 and 4. The grant caps at €1,800 at exactly 4 kWp. A 5 kWp system gets the same €1,800 — not a penny more. The fifth kWp, which typically means 2 extra panels on your roof, costs an additional €1,000–€1,500 with no grant attached.
That fifth kWp generates another 800–900 kWh per year — the standard Irish average irradiance applied to one extra kWp. At 35c/kWh, that is €280–€315 per year if you use it in the house. If it gets exported at your Clean Export Guarantee rate (15.89c–20c/kWh on standard tariffs as of October 2026, set by your supplier), it is worth less. Blend the two and the extra kWp delivers roughly €200–€350 per year in value, depending on how much of it lands in your own appliances versus onto the grid.
Against an unsubsidised cost of €1,000–€1,500, the payback on that fifth kWp alone is 3–8 years. Heat pump or EV in the house pulling power during the day? You are at the short end. Exporting most of the surplus because you are out at work until 6pm? You are at the long end.
If you have high daytime electricity use, or you are adding a heat pump or EV charger in the next couple of years, the fifth kWp stacks up. If you are a standard 3-bed with gas heating and no EV plans, the 4 kWp gives you the full grant for less money out of pocket.
| System | Gross Cost | SEAI Grant | Net Cost | Annual Generation | Grant per € Spent |
|---|---|---|---|---|---|
| 4 kWp | €8,000–€10,500 | €1,800 | €6,200–€8,700 | ~3,200–3,600 kWh | Best ratio (grant at cap) |
| 5 kWp | €9,000–€11,500 | €1,800 | €7,200–€9,700 | ~4,000–4,500 kWh | Lower (5th kWp unsubsidised) |
SEAI grant is capped at €1,800 for any system 4 kWp or above. The grant structure is €700/kWp for the first 2 kWp and €200/kWp for kWp 3 and 4. Source: SEAI Solar Electricity Grant page.
What Does a 5 kWp System Include?
A fully installed 5 kWp system in Ireland typically includes:
- 10–13 solar panels at 400 W–500 W each (the exact number depends on panel wattage — 10 panels at 500 W, or 13 panels at 400 W, both give approximately 5 kWp)
- A 5 kW inverter (string inverter is standard; microinverters or power optimisers are available at additional cost for shaded roofs)
- Mounting frames and fixings appropriate to your roof type
- DC and AC cabling
- Generation meter
- System monitoring (app-based, usually included)
- Installation labour
- RECI electrical safety certificate
- SEAI grant application assistance
- ESB Networks grid connection notification (NC6/NC7 process)
Ask each installer to confirm the price is fully inclusive of VAT (0% for residential solar since May 2023), the RECI cert, and the ESB Networks grid notification. Some quotes leave these out and add them later. Also check the installer is on the SEAI registered list — without that, there is no grant.
How Much Electricity Does a 5 kWp System Generate in Ireland?
A 5 kWp system on a south-facing Irish roof generates roughly 4,000–4,500 kWh per year. That figure comes from the national average solar irradiance of 800–900 kWh per kWp per year (PVGIS data, European Commission Joint Research Centre) at a 30–40° tilt. Ireland is not Malaga, but the yields are solid enough to stack up financially.
Generation varies by location:
| Region | Irradiance (kWh/kWp/year) | 5 kWp Annual Output | Coverage of 4,200 kWh Home |
|---|---|---|---|
| Wexford / south Leinster | ~965 | ~4,825 kWh | ~115% |
| Cork / south Munster | ~940 | ~4,700 kWh | ~112% |
| Midlands (Laois, Offaly) | ~900 | ~4,500 kWh | ~107% |
| Dublin / east coast | ~880 | ~4,400 kWh | ~105% |
| Connacht (Galway, Mayo) | ~850 | ~4,250 kWh | ~101% |
| North-west (Sligo, Donegal) | ~817 | ~4,085 kWh | ~97% |
Source: PVGIS (Photovoltaic Geographical Information System), European Commission Joint Research Centre. Irradiance figures for south-facing, 35-degree tilt, crystalline silicon panels. Average Irish home electricity consumption: 4,200–4,500 kWh/year (CRU/ESB Networks data).
The coverage figures in the table assume every kWh generated is also used in the house. That does not happen — when no one is home or demand is low, surplus goes to the grid. Without a battery, a typical household self-consumes 30–50% of total generation. The rest exports under the Clean Export Guarantee, earning you whatever rate your electricity supplier is paying — 15.89c–20c/kWh on standard tariffs as of October 2026, though each supplier sets their own rate.
The coverage figures make most sense for homes with a heat pump, an EV charger, or someone working from home who can run appliances during peak solar hours — dishwasher in the morning, EV charging at noon, heat pump timed to the afternoon. Those homes can realistically self-consume 50–70% of what a 5 kWp system produces.
5 kWp Cost Breakdown
| Cost Item | Typical Range | Notes |
|---|---|---|
| 5 kWp system (panels, inverter, mounting, cabling, labour) | €9,000–€11,500 | VAT at 0% already included (since May 2023) |
| SEAI Solar Electricity Grant | −€1,800 | Paid to your bank account, usually 4–6 weeks after the paperwork and post-works BER are in |
| Net cost after grant | €7,200–€9,700 | This is your actual out-of-pocket cost |
| Add: 10 kWh battery storage (optional) | €4,000–€6,000 extra | Flat €600 SEAI battery grant (5 kWh or larger); 0% VAT if on the same contract as the panels |
| 5 kWp + battery (net) | €10,600–€15,100 | After the €1,800 solar grant and the €600 battery grant |
The annual electricity saving for a 5 kWp system is typically €900–€1,400 per year, combining self-consumed savings at approximately 35c/kWh (current average Irish electricity import rate) and export income under the Clean Export Guarantee. The payback period on the net post-grant cost is 7–9 years for most households, falling to about 6 years for homes with high daytime use from a heat pump or EV charger.
Who Should Choose 5 kWp?
Homes with a heat pump
A heat pump adds roughly 2,000–3,000 kWh per year to your electricity bill. It runs on electricity, not gas, and even though it is efficient, that demand is real. A 4 kWp system generating 3,200–3,600 kWh per year gets swallowed up. A 5 kWp system at 4,000–4,500 kWh per year keeps pace far better. The SEAI heat pump grant (up to €14,500 for a house, structured as three separate components — see seai.ie for the breakdown) can be claimed alongside the solar grant.
Homes with an EV charger
Home EV charging adds 2,000–4,000 kWh per year, depending on how much you drive and how much of your charging happens at home versus public chargers. An EV owner who works from home and charges during the day is the best-case scenario for a 5 kWp system: the car absorbs midday solar generation at the full import rate (35c/kWh saved, rather than 16–19.5c/kWh earned from export). That difference matters a lot over the year. The SEAI home charger grant of €300 is a separate application and can be claimed at the same time as the solar grant.
Larger homes with higher base consumption
A 4-bed or 5-bed home typically uses 5,000–7,000 kWh per year, particularly with older appliances, teenagers at home, or no smart-home load management. A 5 kWp system covers 60–90% of that demand in gross generation terms, versus 45–70% for a 4 kWp system.
Homes where the owner plans future upgrades
If a heat pump or EV charger is on the plan in the next two or three years, go to 5 kWp now. Getting a scaffolding company back for one extra panel later costs more than installing it in the first visit. The incremental cost at install time (€1,000–€1,500) is a fraction of what a second mobilisation would run to.
Who should stick with 4 kWp
The 4 kWp system is the right choice for most average 3-bed homes with no heat pump, no EV, gas central heating, and no plans to add either in the near term. It hits the SEAI grant cap exactly, meaning you get the maximum government support per euro of system cost. A 5 kWp system in the same situation generates more electricity than the home can realistically absorb, increasing the proportion exported at the lower Clean Export Guarantee rate rather than offset against the full import price. For those homes, the extra €1,000–€1,500 for the fifth kWp returns less value per year than the same money would in most alternative uses. See the 4 kWp system cost guide for the grant-optimised comparison.
5 kWp With Battery Storage
A battery suits a 5 kWp system better than a 4 kWp, for a straightforward reason: the bigger system produces more midday surplus that would otherwise export at the lower Clean Export Guarantee rate. A battery captures that surplus and holds it for the evening, converting 16–19.5c/kWh (what your supplier pays for export) into 35c/kWh (what you avoid paying for import). That is a difference of roughly €0.15–€0.19 on every kWh the battery stores and releases.
A 10 kWh battery is the most common pairing with a 5 kWp system for larger Irish homes. Add €4,000–€6,000 to the system price. If that is more than you want to spend, 5 kWh is the smallest size the grant will touch and the cheapest way in: our 5 kWh solar battery price guide puts it at €1,500–€2,500 added to a new install. Either size earns the same flat €600, because SEAI pays a set rate for anything 5 kWh or larger rather than a rate per kWh, and the €1,800 solar grant is still worked out on the panels alone. A well-used 10 kWh battery cycling once daily adds roughly €300–€600 a year on top of what the solar generates, so payback on the battery portion runs 8–12 years, longer than the panels.
That used to be the argument for fitting panels now and a battery later. The VAT rules have made it a costly plan. SEAI states that a battery installed at the same time as solar panels carries 0% VAT and that a standalone battery installation carries 23% VAT on top of the cost, so coming back in two years for a 10 kWh battery adds €920 to €1,380 in VAT alone. On top of that, SEAI notes the string inverter fitted with a standard solar installation is not compatible with battery storage, so a retrofit often means a hybrid inverter as well. If a battery is on the cards at all, the cheapest day to fit it is the day the panels go up.
Battery brands commonly specified by Irish installers include SolarEdge (Energy Bank), Growatt (ARK series), Pylontech (Force H2), and BYD (Battery-Box Premium). When reviewing any quote that includes a battery, check that the installer specifies: brand, chemistry (lithium iron phosphate is the current standard for safety and cycle life), warranty years, and throughput warranty in kWh — that last figure tells you how many total kWh the battery is warranted to cycle over its life.
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Get a Quote →Frequently Asked Questions
A 5 kWp solar system costs €9,000–€11,500 installed in Ireland in 2026, or €7,200–€9,700 after the €1,800 SEAI Solar Electricity Grant. The 0% VAT rate (in effect since May 2023) is already factored into those figures — installers quote at 0% for residential solar PV by default. You apply on the SEAI MGEN portal before work starts, and the grant is paid to your bank account, usually 4–6 weeks after the paperwork and post-works BER are in.
A 5 kWp solar system generates approximately 4,000–4,500 kWh per year in Ireland. This is based on the national average solar irradiance of 800–900 kWh per kWp per year (PVGIS data, European Commission). The figure is higher in the south and east (Cork, Wexford reach 4,700–4,825 kWh/year) and lower in the north-west (Donegal approximately 4,085 kWh/year). For comparison, the average Irish household uses 4,200–4,500 kWh of electricity per year (CRU/ESB Networks data), meaning a 5 kWp system covers roughly 90–107% of average consumption in gross terms.
Yes, but the grant is capped at €1,800 regardless of system size above 4 kWp. The SEAI Solar Electricity Grant pays €700 per kWp for the first 2 kWp and €200 per kWp for kWp 3 and 4, reaching the €1,800 maximum at exactly 4 kWp. A 5 kWp system receives the same €1,800 as a 4 kWp system — the fifth kWp attracts no additional grant. You must use an SEAI-registered installer to qualify. See the full eligibility conditions on the SEAI grant page.
A 5 kWp solar system uses 10–13 panels, depending on panel wattage. At 500 W per panel (common in 2026 installs), you need 10 panels. At 400 W per panel, you need 13. Most Irish installers currently specify 400 W–500 W monocrystalline panels, so the most common configurations are 10, 11, or 12 panels. Roof space required is approximately 30–40 m² for a 5 kWp system. See the solar panel sizing guide for roof space calculations by system size.
The payback period for a 5 kWp system in Ireland is typically 7–9 years after the €1,800 SEAI grant. Homes with a heat pump or EV charger that absorb a high proportion of generated electricity at the full 35c/kWh import rate achieve payback closer to 6 years. Homes that export most of their generation at the Clean Export Guarantee rate (15.89c–20c/kWh on standard tariffs) see payback at the longer end of the range. After payback, the system produces free electricity for the remaining life of the panels (typically 25+ years).
5 kWp is better for homes with a heat pump, EV charger, or higher-than-average electricity use. 4 kWp is better for a standard 3-bed home with gas heating and no EV — it hits the SEAI grant cap exactly, giving maximum government support per euro spent. The fifth kWp adds approximately €1,000–€1,500 in unsubsidised cost and generates an extra 800–900 kWh per year. That is worth €200–€350 annually depending on how much you self-consume versus export. If your home can absorb the extra generation, it pays back in 3–5 years. If most of it is exported at a low Clean Export Guarantee rate, payback on that portion stretches to 6–12 years.
A 5 kWp solar system requires approximately 30–40 m² of usable roof space. Each 400 W–500 W panel covers roughly 2.0–2.1 m², and a 5 kWp system uses 10–13 panels. Usable roof space means unshaded, structurally sound, facing south to west with a pitch of 15–50 degrees. Any significant shading from chimneys, dormers, or adjacent buildings reduces effective roof space. Your installer will measure and assess the roof as part of a site survey before quoting — always request a site survey before signing a contract.
Yes. A battery can be added to a 5 kWp system either at the time of installation or as a retrofit later. A 10 kWh battery is the most practical pairing for a 5 kWp system — it can store a full afternoon of surplus generation for evening use. Installed cost for a 10 kWh battery in Ireland is €4,000–€6,000, with a separate flat €600 SEAI battery grant available from 6 October 2026 for batteries of 5 kWh or larger. SEAI states that a battery installed at the same time as the panels carries 0% VAT, while a standalone battery installation carries 23% VAT on top of the cost, so fitting the battery with the panels saves €920 to €1,380 at these prices.
Sources: SEAI Solar Electricity Grant — grant tiers and eligibility; PVGIS (Photovoltaic Geographical Information System), European Commission Joint Research Centre — Irish solar irradiance by county; CRU/ESB Networks — average Irish household electricity consumption (4,200–4,500 kWh/year); Revenue.ie — microgeneration income tax exemption (€400/year tax-free threshold for 2026, with €600 announced in Budget 2027; verify current status at revenue.ie before advising clients); CRU — Clean Export Guarantee framework.
Published: 2026-05-26. Author: Neil Russell. Fact-checked against live SEAI, Revenue, and CRU sources.