The output of a wind turbine depends on the turbine's size and the wind's speed through the rotor. An average onshore wind turbine with a capacity of 2.5–3 MW can produce more than 6 million kWh in a year – enough to supply 1,500 average EU households with electricity.An average offshore wind turbine of 3.6 MW can power more than 3,312 average EU households.n average onshore wind turbine with a capacity of 2.5–3 MW can produce more than 6 million kWh in a year – enough to supply 1,500 average EU households with electricity. An average offshore wind turbine of 3.6 MW can power more than 3,312 average EU households.