Home EnergySolar Payback Calculator

Energy

Solar Payback Calculator

Calculate the payback period and lifetime savings of installing solar panels. See if solar makes financial sense for your home.

Enter Your Values

Using shared profile · 3,500/mo · EUR — edit on Dashboard

Start from a realistic scenario

System

System Cost (after incentives)

€

System Size

Analysis Period25 yrs

530

Savings

Electricity Price

€

Self-Consumption %50 %

10100

Results update automatically as you change values.

Decision Engine

Understand

Enter only what matters

Calculate

Transparent formulas

Compare

Side-by-side options

Hidden Costs

What you might forget

Scenarios

Best, expected, worst

Decide

Clear recommendation

Decision Verdict

Payback Period

6 years

Your 6kW solar system costs €8000 and saves €1470/year net (€1080 from self-consumption at €0.30/kWh + €540 from export at €0.15/kWh - €150 maintenance).

Payback Period

6 years

Year 1 Net Savings

€1,470

7 things you might be forgettingEstimate based on your inputs — not guaranteed financial advice.

Decision Engine

Confidence

45/ 100

Decision confidence

6 years

Payback Period

Watch-outs

Sensitive to your assumptions

The outcome swings widely between best and worst cases. Tighten the key inputs before you rely on this.

Hidden costs add up

Easily-forgotten costs total about €1,692 a year — enough to change the answer.

Your action plan

1Pin down "Electricity Price" — it moves the result by up to 7 years, more than anything else.
2Budget for the 7 hidden costs before you commit.
3Sanity-check the worst case (9 years) — can you live with it?
4Adjust the inputs to match your real numbers, then revisit the verdict.

Your Results

Styled PDF reports — Pro

Payback Period

6 years

Year 1 Net Savings

€1,470

25-Year Total Savings

€57,681

Net Profit

€49,681

ROI

621.0%

Annualized Return

8.8%

CO₂ Saved

33,750 kg CO₂

Decision Summary

Your 6kW solar system costs €8000 and saves €1470/year net (€1080 from self-consumption at €0.30/kWh + €540 from export at €0.15/kWh - €150 maintenance). It pays for itself in 6 years, generating €57681 in total savings over 25 years — a net profit of €49681 (621% ROI, 8.8%/yr). This beats investing the same money at 7.000000000000001%. You also save 33.8 tonnes of CO₂.

What-If Scenarios

Results update instantly

Electricity Price0.30 €/kWh

0.1 €/kWh0.8 €/kWh

Price Inflation4.00 %

0 %10 %

Analysis Period25 yrs

5 yrs30 yrs

Cost Breakdown

System Cost

€8,0006.2%

25yr Maintenance + Inverter

€5,2504.1%

Total Savings

€65,68151.1%

Net Profit

€49,68138.6%

Payback Timeline

Net Investment

Cumulative Net Savings

Click chart to expand

Annual Net Savings (incl. inverter)

Click chart to expand

What You Might Be Forgetting

Hidden costs and factors that are easy to overlook but can significantly impact your decision.

Inverter Replacement

Inverters typically need replacement after 10-15 years. Budget €1500 at year ~12. This is included in your calculation.

Est. annual

€125

Maintenance & Cleaning

€150/year for cleaning and inspection. Dirty panels can lose 15-25% efficiency. Over 25 years: €3750.

Est. annual

€150

Opportunity Cost

If you invested the €8000 at 7.000000000000001% instead, you'd have €43419 after 25 years. Solar's net profit of €49681 needs to beat this to be worth it.

Est. annual

€1,417

Roof Condition

If your roof needs replacement within the next 10 years, do it before installing solar. Removing and reinstalling panels costs €2,000-5,000.

Insurance Increase

Adding solar panels to your home insurance may increase premiums by €50-150/year.

Panel Degradation

Panels lose ~0.5%/yr. Year 1 production: 7200 kWh. Year 25: 6384 kWh — a 11.3% drop.

Grid Fees & Export Limits

Some utilities charge fixed grid fees (€45/yr) even with solar. Feed-in rates (€0.15/kWh) are often lower than import rates (€0.30/kWh), so self-consumption matters more than export.

Scenario Analysis

How the outcome shifts if your assumptions turn out better or worse than expected.

PaybackLikely range

4 yearsto9 years

Best Case

High electricity prices, high self-consumption

Payback

4 years

Net Profit

€64,586

Expected

At your stated values

Payback

6 years

Net Profit

€49,681

ROI

621.0%

Worst Case

Low electricity prices, high degradation

Payback

9 years

Net Profit

€24,841

Compare Scenarios

Pin up to 3 and see them side by side

Set your inputs, then Pin current to save this scenario. Pin a few variations to compare their scores and outcomes here.

What Moves the Needle Most

How much each factor changes your Payback Period across its full range. Electricity Price has the biggest impact.

Electricity Price0.1 €/kWh → 0.8 €/kWh

±4 years

3 years10 years

Price Inflation0 % → 10 %

±1 years

5 years6 years

Focus your attention on Electricity Price — getting it right matters most. Factors lower down move the result less, so rough estimates there are fine.

Confidence & Assumptions

Low confidence

The result swings widely between best and worst cases — it depends heavily on assumptions that are hard to predict.

Payback: 9 years (worst) → 6 years (expected) → 4 years (best)

Key assumptions

Electricity Price0.3 €/kWh

Price Inflation4 %

Analysis Period25 yrs

These are the estimates the result depends on. Adjust them (and the Advanced inputs) to match your real situation — the closer they are to reality, the more reliable your decision.

These estimates are for informational purposes only and do not constitute financial advice. Actual results may vary based on factors not captured in this calculator.

How This Calculator Works

What this calculator does

This calculator determines how many years it takes for solar panel savings to equal the system cost (payback period), and the total profit over the system lifetime.

How the calculation works

We calculate annual savings from self-consumed solar (offsetting grid electricity) and exported surplus (feed-in tariff). Savings grow with electricity inflation and decline with panel degradation. Payback is when cumulative savings exceed system cost.

Formula

Annual Savings = Production × Self-Consumption × Price + Production × (1-Self-Consumption) × Feed-in Rate
Payback = System Cost / Year 1 Savings (approximate)
Lifetime Savings = Σ (Savings × (1-degradation)^t × (1+inflation)^t)

Sources & defaults

IEA / national renewable energy agencies
Panel degradation, yield, and lifetime assumptions
Eurostat / national CPI
Default inflation ~2–3% unless you override it
Self-consumption × retail price + export × feed-in
Savings escalate with electricity inflation and decline with degradation

Example

6kW system, €8,000 cost, 7,200 kWh/year, €0.30/kWh, 50% self-consumption: Year 1 savings ≈ €1,620. Payback ≈ 5-6 years. 25-year net profit ≈ €32,000.

How to Use This Calculator

1
Enter your numbers
Fill in the inputs for Solar Payback Calculator. Defaults are realistic starting points — replace them with your actual figures.
2
Understand the calculation
We calculate annual savings from self-consumed solar (offsetting grid electricity) and exported surplus (feed-in tariff). Savings grow with electricity inflation and decline with panel degradation. Payback is when cumulative savings exceed system cost.
3
Review results and scenarios
Check metrics, cost breakdown, comparison tables, and best / expected / worst scenarios. Use sliders to stress-test assumptions.
4
Decide with the verdict
Read the decision engine recommendation and FAQ. Example: 6kW system, €8,000 cost, 7,200 kWh/year, €0.30/kWh, 50% self-consumption: Year 1 savings ≈ €1,620. Payback ≈ 5-6 years. 25-year net profit ≈ €32,000.

Factors to Consider

Self-consumption ratio greatly affects savings — battery storage helps
Feed-in tariffs are declining in many countries
Panel degradation (~0.5%/year) reduces output over time
Inverter replacement needed after 10-15 years
Government incentives can significantly reduce system cost
Roof orientation and shading affect production

Common Mistakes

Using peak rated output instead of actual annual production
Ignoring panel degradation over time
Forgetting inverter replacement costs
Overestimating self-consumption without a battery
Not accounting for electricity price changes

Frequently Asked Questions

What is a good solar payback period?+

5-8 years is typical in regions with high electricity prices. Under 5 years is excellent. Over 10 years is marginal, though still profitable over 25+ year system life.

Do solar panels work on cloudy days?+

Yes, but output drops 10-25% on cloudy days and 60-80% on very overcast days. Annual production figures already account for typical weather.

Should I get a battery?+

Batteries increase self-consumption from ~30% to ~70%, improving savings. But they add €3,000-8,000 to cost. Use the Solar + Battery Comparison calculator to see if it helps your payback.

This calculator provides estimates for informational purposes only and does not constitute financial, investment, tax, or legal advice. Always consult a qualified professional before making important financial decisions.

Related Calculators

Explore other tools that might help with your decision.

Solar + Battery Comparison

Energy

Electricity Tariff Comparison

Energy

Home Energy Audit Calculator

Energy