[okie01]

I've read that energy payback is about 8 months.

If that's so, why are wind farms usually abandoned when their subsidy expires?

The fact is that wind power is economically feasible only in certain specific circumstances -- such as a residence located off the grid. It is incapable of being a major contributor to the grid.

[thackney]

Subsidies are typical for the construction, not the continued operation.

[DungeonMaster]

If that's so, why are wind farms usually abandoned when their subsidy expires?

Not a true statement.

The fact is that wind power is economically feasible only in certain specific circumstances -- such as a residence located off the grid. It is incapable of being a major contributor to the grid.

Economic feasibility and capable of contributing to the grid are two different things.

Here in Iowa on a windy day we have the equivalent wind power on grid of 5, 1gw nuke power plants.