Between 2012 and 2016, Brattle developed a series of four reports for the Texas Clean Energy Coalition (TCEC) analyzing how renewable and natural gas-fired electricity sources might interact in the Electric Reliability Council of Texas (ERCOT) during the next two decades. Our analysis considered a range of market and regulatory factors including future natural gas prices and greater deployment storage and combined heat and power (CHP). These reports utilized a combination of PSO and Xpand models to capture the interaction of broad system trends and actual power system operations.