Clean energy is energy gained from sources that do not release air pollutants, while green energy is energy derived from natural sources. There is a subtle difference between these two energy types even though they are often spoken of as being the same.
Renewable energy is power generated from sources that are constantly being replenished. These renewable energy resources won’t run out, unlike fossil fuels and gas, and include wind and solar energy.
However, while most green energy sources are renewable, not all renewable energy sources are seen as being green. For example, hydropower is a renewable resource, but some would argue that it is not green, since the deforestation and industrialisation related to the building of hydro dams can damage the environment.
The perfect clean energy mix occurs where green energy meets renewable energy, such as with solar energy and wind energy.
An easy way to remember the differences between these different energy types is:
Clean energy = clean air
Green energy = natural sources
Renewable energy = recyclable sources