Typical system sizes and output for solar panels in Ireland (2026), including panel counts, annual electricity generation and typical household system configurations.
1. Overview
Solar panel systems are typically sized based on:
Available roof space
Household electricity consumption
Budget and grant eligibility
Domestic solar PV systems in Ireland commonly range between:
3 kWp – 6 kWp installed capacity.
System size determines:
Number of panels installed
Annual electricity generation
Overall installation cost
Most households install between:
8 – 16 solar panels depending on roof size.
2. Panel Power Ratings
Modern residential solar panels typically produce:
400 – 450 watts per panel.
This means system capacity increases with panel count.
Example:
| Panel Count | Approx System Size |
|---|---|
| 8 panels | ~3.2 kWp |
| 10 panels | ~4.0 kWp |
| 12 panels | ~4.8 kWp |
| 14 panels | ~5.6 kWp |
| 16 panels | ~6.4 kWp |
Higher efficiency panels can slightly reduce the number of panels required for the same system size.
3. Typical Household System Sizes
| System Size | Panels | Typical Household Suitability |
|---|---|---|
| 3 kWp | 7 – 8 panels | Small households |
| 4 kWp | 9 – 10 panels | Typical semi-detached homes |
| 5 kWp | 12 – 13 panels | Medium electricity demand |
| 6 kWp | 15 – 16 panels | Large households or EV charging |
The most commonly installed system size in Ireland is approximately:
4 – 5 kWp.
4. Annual Electricity Generation
Solar output depends on:
Roof orientation
Roof pitch
Shading levels
Weather conditions
Typical annual generation in Ireland:
| System Size | Annual Generation |
|---|---|
| 3 kWp | 2,700 – 3,000 kWh |
| 4 kWp | 3,600 – 4,200 kWh |
| 5 kWp | 4,500 – 5,200 kWh |
| 6 kWp | 5,400 – 6,200 kWh |
South-facing roofs typically achieve the highest output.
5. Household Electricity Demand Comparison
Typical household electricity usage in Ireland varies widely.
| Household Type | Typical Annual Electricity Use |
|---|---|
| Apartment | 2,000 – 2,500 kWh |
| Small house | 3,000 – 3,500 kWh |
| Semi-detached | 4,000 – 4,500 kWh |
| Large house | 5,000 – 6,000 kWh+ |
A solar system sized close to annual consumption can offset a significant portion of electricity demand.
6. Roof Space Requirements
Solar panel dimensions are typically around:
1.7m × 1.1m per panel.
Approximate roof area required:
| System Size | Roof Area |
|---|---|
| 3 kWp | ~15 m² |
| 4 kWp | ~19 m² |
| 5 kWp | ~26 m² |
| 6 kWp | ~34 m² |
Roof obstacles such as skylights, chimneys or dormers reduce usable panel space.
7. Output Variation by Orientation
Orientation affects annual electricity generation.
| Roof Direction | Output vs South |
|---|---|
| South | 100% |
| South-East / South-West | 90 – 95% |
| East / West | 80 – 90% |
| North-East / North-West | 60 – 75% |
East-west installations may generate more evenly throughout the day.
8. Seasonal Generation Pattern
Solar output varies significantly by season.
| Season | Approx Share of Annual Output |
|---|---|
| Spring | 30 – 35% |
| Summer | 40 – 45% |
| Autumn | 15 – 20% |
| Winter | 5 – 10% |
Most solar electricity is generated between April and September.
Winter production is significantly lower.
9. Example System Output
Example 10-panel system (~4 kWp):
Annual generation:
~4,000 kWh.
If household consumption is:
4,200 kWh annually,
Solar generation could theoretically cover most electricity demand, though timing of usage determines actual savings.
10. Oversizing Considerations
Some households install larger systems than current electricity usage.
Reasons include:
Future EV charging
Heat pump installation
Battery storage integration
Oversizing may increase exported electricity but can future-proof the system.
11. Exported Electricity
Electricity not used immediately within the home may be exported to the grid.
Export levels commonly range:
30% – 70% depending on usage patterns.
Export tariffs provide additional income for exported electricity.
12. Typical 2026 System Summary
Domestic solar PV systems in Ireland typically range:
3 – 6 kWp capacity.
Most common installations include:
10 – 14 panels.
Annual generation typically ranges:
3,500 – 5,500 kWh depending on system size and roof orientation.
System sizing depends primarily on roof space and household electricity demand.
13. Other Resources
Solar Panel Battery Add-On Cost
Installation Process Explained