The PTC subsidy has been extended to help finance wind projects that begin construction before 1 January 2014, but until yesterday it was unclear exactly what "begin construction" meant.
According to IRS Notice 2013-29, released on 15 April, to meet the "under construction" qualification, developers must either: show "physical work of a significant nature" has begun on their project, either at the site, or in a factory to which the developer has given a binding order for specially designed equipment; or show that at least 5% of the total project cost has been incurred.
For wind projects this will typically mean that work has either begun on tower foundations at the project site, or a manufacturer has started work on turbine components specifically ordered for the project. A contract for delivery of turbines that a manufacturer already has stockpiled will not qualify.