They're leaving out an important part of the claim.

I can set up some piezoelectric things in my office chair such that when I sit my fat ass down it generates a small electrical charge. I can say that my ass can generate enough electricity to power a million homes for 10 years, assuming I don't tell you how long it takes to generate that power, which would be on the order of decades, if not centuries, if not longer.

I'd wager someone saw the average energy output for the expected service lifetime of the turbine, then was like, "How much energy does one 3-person household use?" and started playing with Excel until they got a good mix of time and # of households for the press release.