John Robb sums it up.
Our current global energy burn rate is 16 TW (terawatts), which is up from 0.7 TW at the turn of the 20th Century. … It’s very likely, given a judicious evaluation of the data, that this demand will double to 32 TW by 2025 (even with a global 1-2% decline in usage per $ of GDP due to efficiency improvements).
The bulk of the energy we feed this burn rate with is from stored solar — essentially, energy delivered from the sun millions of years ago and stored inside the earth’s crust. The problem we face with stored solar is that it is reaching production limits (particularly crude oil). In combination with this rapidly increasing demand, we will face a never ending series of price increases (occasionally mitigated by demand destruction) for stored solar energy as oil, natural gas, and coal deplete in series.