Sun is the source of solar energy. The sun is always present. Using solar energy, does not make the sun smaller or reduce its ability to provide energy. It is a renewable energy because sun is always present whether we use it or not.
Power of the wind help to generate the wind. Wind can turn the vanes of wind powered generators to produce electricity. Like the sun, the wind is always present whether we choose to use it power or not. It is a renewable energy because wind is always available whether we use it or not.
Formed from the remains of organisms that died millions years ago. It will take millions of years for petroleum to form if we finish using. It cannot be renewed or replenished. So it known as renewable energy.