In its Final Award of 21 January 2016, the Tribunal consisting of Alexis Mourre, Guido Santiago Tawil and Claus von Wobeser dismissed the Claimant investors’ indirect expropriation and fair and equitable treatment (FET) claims under the Energy Charter Treaty (ECT) in Charanne and Construction Investments v Spain (Charanne). This review provides a brief summary of the Claimant’s arguments and the Tribunal’s findings in this first investment treaty case that has been concluded amongst the 27 solar photovoltaic (PV) cases registered against Spain between 2011 and 2015. First, it briefly sketches the modifications in the regulatory framework of the solar PV industry in Spain since the 1990s. Thereafter, it provides an overview of the Final Award, and comments on the strategies adopted by the Tribunal in addressing issues of compatibility of the ECT with EU Law and in interpreting the doctrine of legitimate expectations.