Exactly 1 year ago we had our solarpanels installed on our roof. Time to check if all the nice expectations are fulfilled.


  • Install date: september 20th, 2012
  • 13 x 240 Wp panels
  • 3120 Wp total
  • Pointed towards the east-south-east
  • Supplier estimate: 2800 kWh / year (they said it was a positive number)
  • My own calculated negative scenario: 2200 kWh / year
  • My own calculated positive scenario: 2500 kWh / year
  • Final return: 2663 kWh (sept 20th 2012 – sept 20th 2013)
  • Revenue: 2663 x 0.21 = EUR 559,-

Conclusion: As expected the estimate of the supplier is on the positive side, but the generated returns and revenue is sufficient to cover the investment. The solarpanels cover about 65% of our yearly electricity consumption.

Details can be found here at pvoutput.org.

Now looking forward to january 1st 2014 to see what the revenue over 2013 is.