[jhayward]

The tax breaks are built in for the life of the wind farms, so they don't really expire until the farms are retired.

The culprit is not actually the PTC, it's the combination of the PTC and insufficient transmission capacity from the wind farms to the rest of the state. When additional transmission capacity is added the wind generation will be absorbed (and paid for) by a much larger region and the incentive to under-price will go away.