How long do you think it will be before renewable energy becomes normal and overtakes fossil fuels as our main source

Question: How long do you think it will be before renewable energy becomes normal and overtakes fossil fuels as our main source of power?
- Keywords:
  fossil fuel,
  power,
  renewable energy,
  source
Asked by 969cars48 to Tadhg on 29 Sep 2017.
- Tadhg O'Donovan answered on 29 Sep 2017:
  
  Always dangerous to predict the future, but I think it might happen in the next 50 years or so. There are a couple of very big challenges at the moment: 1) renewables are still very expensive and 2) they are “intermittent”; the sun doesn’t always shine and the wind doesn’t always blow, so we need to work on energy storage/batteries etc

Question: How long do you think it will be before renewable energy becomes normal and overtakes fossil fuels as our main source of power?