How exactly are sunlight and the wind renewed?
Seems that the term should be "unreliable energy."
Hydro-electric is renewed every time it rains and fills a lake behind a dam. Coal plants are renewed every time a new train of coal arrives. Nuclear power plants are renewed every time the rods are replenished. And they are all reliable sources of power.
Wind and Solar are renewed in the same way as hydro. Additional energy from the Sun strikes the earth, creating sunlight and associated weather.