Tax incentives for green investments: limits to state cutbacks. A reflection on legitimate expectations and fair and equitable treatment of investors

Can a State which has heavily incentivized long-term green investments for several years subsequently change the applicable framework, thus reducing the benefits for investors? To what extent and within which limits? This chapter explores these issues in the case law of the Spanish Constitutional and Supreme Courts, and above all in the arbitration awards issued by international arbitration tribunals, and reveals the existence of a double standard. It mainly focuses on the limits according to the Energy Charter Treaty and general principles of law - in particular, the need for fair and equitable treatment of investors and related aspects such as the concept of legitimate expectations and the principle of non-retroactivity. However, it also tackles correlated issues, such as the intersection between the EU State aid regime and the principle of legitimate expectations; and the different treatment of national and foreign investments.