Many states around the world provides support and incentive to encourage renewable energy. Some states like Spain, Italy and the Czech Republic have withdrawn the incentives or subsidies that have been offered to them. Such regulatory changes had a detrimental impact on the investors and in the development and growth of renewable energy. The regulatory changes made by Spain had adversely affected their investments in breach of the Energy Charter Treaty (ECT). The investor argued that Spain has failed to provide Fair and Equitable Treatment as required by the ECT. In this regard, the arbitral tribunal issued an award ordering the Spain to pay compensation to the investors for loss suffered as a result of Spain’s breach of the ECT.

For ref: https://www.bakermckenzie.com/en/insight/publications/2020/03/renewable-energy-investments