Solar Panel Calculator Ireland
Find out how many solar panels you need and how much you could save. Enter your monthly electricity bill and available roof space below.
* Estimates based on average Irish solar irradiance (1000 kWh/m²/year), 18% panel efficiency, and €0.36/kWh electricity cost. Actual results may vary.
How to Use the Solar Panel Calculator
Our free solar panel calculator estimates how many panels your Irish home needs, what they will cost, and how quickly they will pay for themselves. Simply enter your monthly electricity bill and available roof space, and the calculator does the rest.
The calculations use Ireland-specific data: average solar irradiance of 1,000 kWh/m² per year, standard panel efficiency of 18%, and current electricity costs of €0.36/kWh. Results show the number of panels needed, estimated annual savings, and your payback period.
What the Results Mean
- Number of panels needed — based on your electricity consumption and standard 400W monocrystalline panels (1.7m² each)
- Estimated annual savings — how much you could save on electricity bills per year at current rates
- Payback period — how many years until the panels have paid for themselves (assuming €300 per panel average cost)
These are estimates based on average conditions. Your actual savings depend on roof orientation, shading, and how much electricity you use during daylight hours. For an exact quote tailored to your home, get your free personalised solar quote.
Solar Panel Costs in Ireland 2026: Quick Reference
| System Size | Panels | Cost Before Grant | SEAI Grant | Cost After Grant | Annual Savings |
|---|---|---|---|---|---|
| 2 kWp | 5 | €3,500 | €1,800 | €1,700 | €400–€550 |
| 3 kWp | 7-8 | €5,000 | €2,100 | €2,900 | €550–€750 |
| 4 kWp | 10 | €6,500 | €2,400 | €4,100 | €700–€950 |
| 5 kWp | 12-13 | €8,000 | €2,400 | €5,600 | €850–€1,100 |
| 6 kWp | 15 | €9,500 | €2,400 | €7,100 | €950–€1,250 |
All prices include installation, panels, inverter, mounting, wiring, and VAT (0% for residential). The SEAI grant covers €900/kWp for the first 2kWp and €300/kWp for the next 2kWp, up to a maximum of €2,400. See our complete solar panel costs guide for a detailed breakdown.
Factors That Affect Your Solar Panel Calculation
- Roof orientation — south-facing produces 100% of potential output, east/west produces 80-85%. See our east and west facing roof guide.
- Shading — trees, chimneys, or neighbouring buildings can reduce output by 10-30%
- Roof space — each panel needs approximately 1.7m². A typical semi-D has 20-35m² of usable roof. See our roof space guide.
- Panel efficiency — premium monocrystalline panels (20-22% efficiency) generate more per square metre. See our panel types comparison.
- Battery storage — adding a battery increases self-consumption from 30-40% to 60-80%, boosting savings. See our battery storage guide.
- Export income — surplus electricity earns €0.155-0.185/kWh through the Clean Export Guarantee. See our CEG guide.
SEAI Solar Panel Grant 2026
The SEAI grant reduces your upfront cost by up to €2,400. You must apply before installation begins, and your installer must be SEAI-registered. The grant is available to all homeowners in Ireland whose home was built and occupied before 2021. See our complete SEAI grant guide for eligibility and step-by-step application instructions.
Ready for an Exact Quote?
This calculator gives you a solid estimate, but every home is different. Roof angle, shading, wiring distance, and your specific electricity usage pattern all affect the final cost and savings. For an exact, personalised quote from an SEAI-approved installer in your area, get your free solar quote here — it takes 60 seconds and there is zero obligation.
Frequently Asked Questions
How many solar panels do I need for a 3-bed house in Ireland?
A typical 3-bed semi-detached house needs 8-12 solar panels (3.2-4.8 kWp) to cover 50-80% of annual electricity usage. This assumes a monthly bill of €150-€200. See our full sizing guide.
How much do solar panels cost in Ireland in 2026?
A typical 4kWp system costs €6,500 before the SEAI grant, or approximately €4,100 after the grant. Prices range from €3,500 for a small 2kWp system to €14,500 for a large 10kWp installation.
How accurate is this solar calculator?
The calculator provides a reliable estimate based on average Irish conditions. Actual results may vary by 10-20% depending on your roof orientation, shading, and electricity usage pattern. For a precise figure, request a free professional site assessment.
Do solar panels work in Ireland's cloudy weather?
Yes. Ireland receives 950-1,100 kWh/m² of solar irradiance per year — enough for excellent solar returns. Panels produce electricity even on cloudy days (10-25% of peak output). The cooler Irish temperatures actually improve panel efficiency compared to hotter climates. See our solar panel output guide.
How long do solar panels take to pay for themselves in Ireland?
Most residential solar systems in Ireland pay for themselves in 5-8 years after the SEAI grant. After that, you are generating essentially free electricity for the remaining 17-20 years of the panels' lifespan.
Can I sell excess electricity back to the grid?
Yes. Through the Clean Export Guarantee (CEG), you earn €0.155-0.185 per kWh for surplus electricity you export. A typical 4kWp system exports 2,000-2,500 kWh per year, earning €300-€450 annually. See our Clean Export Guarantee guide.
Do I need planning permission for solar panels?
No, most residential solar installations are exempt from planning permission since the 2022 exemptions. You can install up to 50m² of panels without any planning application. See our planning permission guide.