Payback of carbon within 3 years

The winter rain has meant that even though last summer was very dry, we have exported more than our annual target of 117,600 kWh in the year April 2015 – March 2016. We estimated the carbon footprint of the installation to be 150 tonnes (Te) of carbon to cover the CO2 used for things such as production, transport and concrete in the installation. According to DECC, 0.542Te CO₂ is saved per MWh of electricity produced, therefore we needed to generate 276.7 MWh to cover the CO₂. We have in effect paid back the carbon used in the production and installation of the turbine within 3 years of starting generating (payback date = 19^th November 2015).