With the extensions to the tax credits passed in December, Congress gave solar a better tax deal than wind for two reasons: it has a smaller share of the US generation mix (1% versus about 4.7% at the end of 2015); and the ITC has only been around for ten years versus 23 for the PTC.

While it renewed both for five years, the PTC’s took effect retroactively on 1 January 2015, when it last expired, and will remain through to the end of 2019.