What does a 10MW wind turbine mean?
A 10 MW wind turbine can be expected to output 10 MW (power) at the rated wind speed. If the wind remained at that speed for one hour then the output would be 10 MWh (energy). Over 24 hours that would total 240 MWh. At, say, 5 c/kWh that would be worth €12k.

I can't find a figure but I suspect that, on average, the output will be about one third of the rated output due to calm days, etc.

Have a look at the Wind chapter of David McKay's excellent Sustainable Energy Without the Hot Air which is available in book form or free PDF or HTML form. It provides figures relevant to Britain but the principles apply anywhere.