Coal power is not base-load electricity by itself. To enable coal to reliably deliver electric power, it took the creation of an entire other national infrastructure; the trans-continental railroad system.
Without the unceasing rail-car-load delivery, every 12 hours, on the hour, hour after hour, day after day, week after week, year after year, of every next 12-hour-supply of fuel for the fire; the fire would go out, the water wouldn’t boil, the steam wouldn’t rise, the turbine wouldn’t turn; the next 12 hours of electricity wouldn’t be made. The fire must never go out.
Coal plus railroad = base-load power.
Even today, a century later, every 12 hours in this nation a trainload of coal from Wyoming or Pennsylvania or Ohio, must arrive at an electric power station near your city, to make your coal power for the next 12 hours. No trainload of coal; no coal power. What does that have to do with wind storage?
Wind plus storage = base-load power.