CPS Energy is trying to prevent large electricity bills for its customers. On Friday, the city-owned utility company announced it filed a suit against the Electric Reliability Council of Texas (ERCOT) in Bexar County District Court to protect its customers from excessive, illegitimate, and illegal prices. CPS is suing ERCOT for breach of contract, negligence and violation of the Texas Constitution. The suit comes after ERCOT forced energy companies to conduct 15-mintue rolling outages during the devastating February snowstorm. The action left many Texans without heat and power for days. "The injustice of imposing an erroneous, excessive and unlawful cost on San Antonians who suffered during a storm cannot be allowed," Mayor Ron Nirenberg said in a press conference with CPS on Friday. "ERCOT botched the storm response, and the regulators should be held accountable for their own mistakes."