Advanced Energy Calculator
Professional-grade tools for accurate ROI analysis
Advanced ROI Calculator
Professional analysis with 25-year projections
Payback on a 4kW kWp system
4.6 years
€1300 a year against a net cost of €6,000 after the SEAI grant, on a south-facing roof with 0% shading.
- Adjusted annual generation
- 3700 kWh/yr
- Annual saving
- €1300
- Net cost after grant
- €6,000
- Payback period
- 4.6 years
- Profit over 25 years
- €26504
Generation is adjusted for orientation and shading, which are the two inputs that most often make a real installation underperform its quote. Savings assume today's electricity price and today's export rate; both move, and the export rate has fallen since the scheme began. Panels degrade roughly 0.5% a year, which the 25-year figure accounts for.
25-Year Cumulative Savings
Unlock the Month-by-Month Breakdown
See how generation varies across the year, so you know what to expect in December vs June.
Upgrade to Premium - €4.99/monthMonth-by-Month Generation Breakdown
Battery Storage Optimizer
Calculate optimal battery size for night rate arbitrage
Typical: 6-10 kWh
4kW system ≈ 10-12 kWh/day
Savings Breakdown
Smart Tip: If your solar generates more than 8kWh daily, a 10kWh battery maximizes ROI through night rate arbitrage.
Heat Pump Suitability Checker
Check if your home is ready for a heat pump
✓ Suitable for Heat Pump
Your BER rating of C1 meets the minimum requirement (C3). A heat pump will work efficiently in your home.