Renewable energy are created from unlimited access of the source.
Some of these renewable sources include wind, water, and sun.
wind = we use windmills to create energy
sun = we use solar panels to create energy.
These sources are given by nature and is unlimited- we don't have to worry about it every depleting.
The opposite is nonrenewable energy which come from nonrenewable sources such as coal and oil. They take a very long time to replenish- I'm talking tens of years.