Wind and solar combined to generate more than 23% of electricity last quarter in the main Texas grid, ERCOT, with solar exceeding 1% for the first time in a single month in the nation’s largest state power market.

Data for March underscores a trend where wind and now solar are gaining share amid robust electricity demand largely at the expense of coal, the former long-time king of power generation there which is struggling to compete against cheaper renewables and plentiful natural gas.