Abstract
Thesist analyzes how regulatory changes related to renewable energy investment support schemes can be perceived under international investment law standards and how possible decisions of international investment law tribunals could impact investment in this sector. This research is based on case studies of two states: Spain and the Czech Republic and claims against them. These cases will assist in analyzing the effects of the amendment/revocation of renewable energy support schemes. Answers to the main question consist of several aspects: an overview the specific features of renewable energy investment; an overview of the regulatory changes in the case study states that has led states to numerous international investment law claims; relevant international investment law rules, case law and their possible application to the given cases; and an analysis of the possible future consequences of arbitral decisions in this sector.