(April 7, 2020, 3:46 PM EDT) -- WASHINGTON, D.C. — A group of U.K. investors in solar energy plants on March 25 filed a complaint in District of Columbia federal court seeking an order recognizing and enforcing an arbitral award of 28.2 million euros, plus costs, against the Kingdom of Spain for a dispute related to regulatory changes in Spain that the investors claim harmed their investments (InfraRed Environmental Infrastructure GP Limited, et al. v. Kingdom Of Spain, No. 20-0817, D. D.C.)....