5kW Solar System Cost in Ireland (2026)

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 €1,200–€2,000 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 (typically 18c–25c/kWh, 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 €1,200–€2,000, the payback on that fifth kWp alone is 4–10 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	€7,000–€10,000	€1,800	€5,200–€8,200	~3,200–3,600 kWh	Best ratio (grant at cap)
5 kWp	€8,000–€11,000	€1,800	€6,200–€9,200	~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)

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 — typically in the range of 18c–25c/kWh, 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)	€8,000–€11,000	VAT at 0% already included (since May 2023)
SEAI Solar Electricity Grant	−€1,800	Paid to your bank account 4–6 weeks post-install via SEAI portal
Net cost after grant	€6,200–€9,200	This is your actual out-of-pocket cost
Add: 10 kWh battery storage (optional)	€4,500–€7,000 extra	No additional grant for battery; 0% VAT still applies
5 kWp + battery (net)	€10,700–€16,200	After the €1,800 grant applied to the solar PV element

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 8–11 years for most households, falling to 7–8 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 €12,500 from 3 February 2026, 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 15–25c/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 (€1,200–€2,000) 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 €1,200–€2,000 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 15–25c/kWh (what your supplier pays for export) into 35c/kWh (what you avoid paying for import). That is a difference of €0.10–€0.20 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 €4,500–€7,000 to the system price. There is no SEAI grant for the battery — the €1,800 applies to the solar PV element only. A well-used 10 kWh battery cycling once daily adds roughly €300–€600 per year in savings on top of what the solar alone generates. Payback on the battery portion is typically 8–12 years, which is longer than the solar panels themselves. That is why most installers suggest starting with solar, then adding a battery in a few years once panel and battery prices have moved further.

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.

Frequently Asked Questions