Umbrella clause
Arbitrary, unreasonable and/or discriminatory measures
https://globalarbitrationreview.com/article/1159066/new-icsid-claims-against-bulgaria-and-kuwait (requires subscription)
https://www.iareporter.com/articles/bulgaria-faces-its-first-known-arbitration-claim-from-a-foreign-investor-in-renewable-energy-generation-sector/ (requires subscription)
https://www.iareporter.com/articles/bulgaria-may-face-bit-and-human-rights-claims-over-renewable-energy-measures/ (requires subscription)
https://energycharter.org/what-we-do/dispute-settlement/investment-dispute-settlement-cases/114-acf-renewable-energy-limited-v-republic-of-bulgaria/
https://www.iareporter.com/articles/balkans-round-up-slovenian-and-macedonian-cases-are-discontinued-bulgaria-case-moves-to-the-merits-and-awards-loom-in-a-quartet-of-other-cases-in-the-region/ (requires subscription)
https://globalarbitrationreview.com/article/solar-investor-wins-ect-claim-against-bulgaria (requires subscription)
https://www.iareporter.com/articles/analysis-tribunal-in-acf-v-bulgaria-finds-that-measures-interfering-with-renewable-energy-incentives-violated-clear-expectation-of-regime-stability/ (requires subscription)