Solar Power Calculator

Simple user friendly Solar Power Calculator

Our easy to use simplified Solar Power calculator

Solar investment estimator

2026 SEAI grant · smart meter rates · national averages

€150
Figures are based on total electricity consumption for a standard 3-bed home. Your bill already reflects your usage — whether you have an EV, heat pump, or high household demand.
Include battery storage
Adds ~€3,000–€5,000 · no SEAI grant available for batteries
Estimated system size—
Gross installation cost—
SEAI grant (2026)—
Net investment—
Annual bill savings
—
CEG export income
—
0 yrs — yrs 15 yrs

Estimates only — actual results vary. Roof orientation, pitch, and shading all affect how much electricity your panels generate. South-facing roofs at 30–40° typically perform best; east or west-facing roofs produce around 80% of that. Location also matters — homes in the south of Ireland receive more solar irradiance than those in the north and west. Always get a quote from an SEAI-registered installer who can assess your specific roof before making any decision. All figures assume 0% VAT and 2026 SEAI grant caps.

How the solar calculator works

The figures shown in the estimator above are based on a €250 monthly electricity bill — roughly the national average for a higher-usage Irish home. Here's exactly how each number is calculated.

Step 1 — System size: Monthly bill ÷ 36 = kWp needed  →  €250 ÷ 36 = 6.9 kWp
Step 2 — Gross cost: kWp × €1,800 per kWp  →  6.9 × €1,800 = €12,420
Step 3 — SEAI grant: €700/kWp for first 2kWp + €200/kWp up to 4kWp, capped at €1,800
Step 4 — Net investment: Gross cost − grant  →  €12,420 − €1,800 = €10,620
Step 5 — Annual returns: Bill savings + CEG export income  →  €1,101 + €826 = €1,927/yr
Step 6 — Payback: Net investment ÷ annual returns  →  €10,620 ÷ €1,927 = 5.5 years
System sizing
Why divide by 36?
A rough rule of thumb used by Irish installers: every €35–€40 of monthly electricity spend equates to approximately 1 kWp of solar needed to meaningfully offset it. We use €36 as the midpoint. A €250 bill suggests a 6.9 kWp system.
Installation cost
€1,800 per kWp
This reflects the mid-market installed price for quality components in Ireland in 2026, including labour, inverter, and mounting. Prices vary — budget installers may quote less; premium systems with microinverters will cost more. All figures assume 0% VAT.
Bill savings — €1,101/yr
Self-consumed solar
A standard home self-consumes around 40% of what its panels generate. We estimate annual generation at 950 kWh per kWp, so 6.9 kWp × 950 × 40% = 2,622 kWh used directly. At the national average rate of 42c/kWh, that's €1,101 saved annually.
CEG export — €826/yr
Clean Export Guarantee
The remaining 60% of generation (3,933 kWh) is exported to the grid. Under the Clean Export Guarantee, suppliers pay around 21c/kWh for exported electricity. That gives 3,933 × €0.21 = €826 in annual export income on top of bill savings.

Assumptions used in this estimate

Monthly bill entered€250
Sizing formulaBill ÷ 36 = kWp
Cost per kWp installed€1,800 (incl. labour, 0% VAT)
Annual generation per kWp950 kWh (Irish average)
Self-consumption rate40% (standard home, no battery)
Electricity unit rate42c/kWh (national smart meter average)
CEG export rate21c/kWh (mid-market 2026)
SEAI grantUp to €1,800 (2026 cap)
VAT on solar panels & installation0% (since May 2023)
Battery storageNot included in this example

These figures are estimates based on national averages and standard assumptions. Your actual savings will depend on roof orientation, shading, local solar irradiance, how much electricity you use during daylight hours, and the components chosen by your installer. South-facing roofs at 30–40° will outperform east or west-facing roofs. Homes in the south of Ireland receive more solar energy than those in the north and west. Always get a detailed quote and projection from an SEAI-registered installer before making any financial decision.