The 8.6GW performance in 2015 represents a 77% jump on the previous year’s 4.9GW, according to new figures from the American Wind Energy Association (AWEA).

Following the expiration of the PTC at the beginning of 2015, wind developers spent most of last year unsure when – or whether – the tax credit might be extended again. Still, projects continued being built at a strong clip because they remained eligible for the PTC as long as they began construction before the expiration.