The ruling, which is final, definitively finds Ontario’s DCRs “inconsistent” with Canada’s broader international trade obligations, confirming most of the key elements of the WTO's initial decision handed down in December.

The case was brought against Canada by Japan and the EU in 2010.

Enacted in 2009, Ontario’s Green Energy Act mandated that a certain percentage of all wind and solar kit used in FIT-eligible projects had to be made locally – encouraging a number of manufacturers, such as China-based Canadian Solar, to set up shop in the province.

Experts