ICSID Tribunal Relies on Brattle’s Damages Analyses in Arbitration Concerning Spain’s Renewable Energy Support Regime
In a re-filed arbitration claim concerning Spain’s reforms to its renewable energy support regime, a Brattle team provided analyses and expert testimony on behalf of the claimants, UK investment fund Eiser Infrastructure. An International Centre for Settlement of Investment Disputes (ICSID) tribunal recently ruled that Spain breached the Energy Charter Treaty and awarded Eiser and its Luxembourg subsidiary, Energia Solar, more than €260 million. The tribunal’s award was based on Brattle’s analysis and is more than double the amount of a prior award to Eiser that had been annulled.
Debevoise & Plimpton first retained Brattle in 2014 to provide analyses on regulatory and quantum issues on behalf of Eiser, which had invested in three Spanish power plants in 2007, when the country offered numerous financial incentives for investors to fund renewable energy projects. When Spain later introduced reforms to the energy subsidiaries regime, Eiser was one of several renewable energy investors to file claims against the country, arguing that the reforms created unfavorable conditions for investors. Eiser was previously awarded €128 million by a different ICSID tribunal in 2017, but that award was annulled in 2020 due to the improper constitution of the original tribunal.
After the original award was annulled, a Brattle team continued to advise the claimants in the re-filed arbitration. Principals Richard Caldwell and José Antonio García, along with Senior Associate Piero Fortino, testified on a wide range of issues, including assessments of the economic reasonableness of Spain’s regulatory changes and the financial impact of the regulatory changes on Eiser’s ongoing performance to the present.
In October 2025, the reconstituted ICSID tribunal ruled that – in violation of the ECT – Spain’s regulatory reforms had fundamentally undermined Eiser’s legitimate expectations. The tribunal relied entirely on Brattle’s damages analysis to award Eiser €262 million plus interest in compensation.
