Legal Disclaimer: This calculator provides estimates for informational purposes only and should not be considered as professional financial, legal, or investment advice. Results are based on assumptions and may not reflect actual costs, savings, or returns. Solar panel performance, electricity rates, and other factors can vary significantly. I accept no personal responsibility for decisions made based on these calculations. Please consult with qualified professionals before making any investment decisions.
Calculate your return on investment for solar panel installation
Select your local currency for all calculations
Total cost of solar panel system including equipment, installation, and permits before any rebates
Peak power rating of your solar system in kilowatts (kW). Check your system specifications or installer quote
Total value of government grants, tax credits, or utility rebates that reduce your upfront cost
Length of solar loan in years. Enter 0 if paying upfront cash
Annual interest rate for your solar loan. Typical rates range from 3-8% depending on credit and lender
Your total yearly electricity consumption in kilowatt-hours. Check your electricity bills for the past 12 months
Your current electricity rate per kilowatt-hour (unit rate only, excluding standing charge). Found on your electricity bill
Fixed daily charge from your electricity supplier, regardless of usage. Found on your electricity bill
Rate you'll be paid for excess electricity exported back to the grid. Check with your energy supplier for current rates
Expected annual increase in electricity prices. Historical average is typically 2-4% per year
Expected operational life of solar panels. Most panels come with 25-year warranties and can last 30+ years
Current estimated value of your home. Used to calculate the immediate value increase from solar installation
Percentage increase in home value due to solar installation. Studies suggest 3-4% is typical
Until ROI breakeven
Total lifetime profit
ROI could be as little as 1 year if you choose to sell your home
The gap between the lines represents your monthly savings with solar.Monthly costs cross over in year 1 - after this point you pay less monthly than without solar.
| Year | Monthly Solar/Loan Cost | Monthly Import Cost | Monthly Export Credit | Monthly Standing Charge | Monthly Net Savings | Cumulative Savings |
|---|---|---|---|---|---|---|
| 1 | £0 | £12 | £18 | £18 | +£66 | £-9,204.6 |
| 2 | £0 | £12 | £18 | £19 | +£68 | £-8,385.338 |
| 3 | £0 | £13 | £19 | £19 | +£70 | £-7,541.498 |
| 4 | £0 | £13 | £19 | £20 | +£72 | £-6,672.343 |
| 5 | £0 | £14 | £20 | £21 | +£75 | £-5,777.113 |
| 6 | £0 | £14 | £21 | £21 | +£77 | £-4,855.027 |
| 7 | £0 | £14 | £21 | £22 | +£79 | £-3,905.278 |
| 8 | £0 | £15 | £22 | £22 | +£82 | £-2,927.036 |
| 9 | £0 | £15 | £22 | £23 | +£84 | £-1,919.447 |
| 10 | £0 | £16 | £23 | £24 | +£86 | £-881.63 |
| 11 | £0 | £16 | £24 | £25 | +£89 | +£187.321 |
| 12 | £0 | £17 | £25 | £25 | +£92 | +£1,288.34 |
| 13 | £0 | £17 | £25 | £26 | +£95 | +£2,422.391 |
| 14 | £0 | £18 | £26 | £27 | +£97 | +£3,590.462 |
| 15 | £0 | £18 | £27 | £28 | +£100 | +£4,793.576 |
| 16 | £0 | £19 | £28 | £28 | +£103 | +£6,032.783 |
| 17 | £0 | £19 | £28 | £29 | +£106 | +£7,309.167 |
| 18 | £0 | £20 | £29 | £30 | +£110 | +£8,623.842 |
| 19 | £0 | £21 | £30 | £31 | +£113 | +£9,977.957 |
| 20 | £0 | £21 | £31 | £32 | +£116 | +£11,372.696 |
| 21 | £0 | £22 | £32 | £33 | +£120 | +£12,809.277 |
| 22 | £0 | £23 | £33 | £34 | +£123 | +£14,288.955 |
| 23 | £0 | £23 | £34 | £35 | +£127 | +£15,813.024 |
| 24 | £0 | £24 | £35 | £36 | +£131 | +£17,382.814 |
| 25 | £0 | £25 | £36 | £37 | +£135 | +£18,999.699 |