They are Renewable- meaning the can be used again and again. And do not emit pollution.
The energy source is constant and reliable.
The wind is never going to go away, neither is the sun (for a long time, anyway.)
It can be accessed anywhere.
There are already houses in the UK that are completely off the grid and actually generate money for the people who live there, as they are able to sell the electricity they don't use to the National Grid.
Low operating cost:
Once built, renewables do not cost much to operate.
They cost lots to build.
Difficult to Generate in Large Quantity.
Coal power plants produce more energy than a field of renewables. This means in the future we may have to lower our energy consumption.
They take up lots of land.
In addition to this, lots of people complain about noise pollution and claim that some energy sources are eyesores.
The energy they make is hard to store:
However, Batteries are currently being created that are capable of storing lots of energy for future use.