The Strategic Environmental Assessment for shale gas exploration has given us four possible fracking futures:

1. No shale exploration
2. Exploration, but no economically viable gas
3. About 5-trillion cubic feet of gas, which would be enough for one 1,000MW power station
4. About 20-trillion cubic feet of gas, which could power two 2,000MW power stations and a gas-to-liquid plant.

 

You can read about them more in-depth here.