By happy coincidence, these seasonal variations perfectly match the electricity demands of the regions. In California, people use more electricity during the summer when air conditioners are used for cooling. Conversely, more people use electricity in Montana during the winter heating months. A 100 percent energy efficient machine would change all the energy put into the machine into useful energy. It would not waste any energy.
Wind machines are just as efficient as coal plants.
Wind plants convert 30 percent of the wind's kinetic energy into electricity. It is the capacity factor of wind plants that puts them a step behind other power plants. Capacity factor refers to the capability of a plant to produce energy. A plant with a 100 percent capacity rating would run all day, every day at full power. There would be no down time for repairs or refueling, an impossible dream for any plant.