By that time (2020), more people should be using solar power in a major way. And the equipment for this type of energy source should be cost efficient because right now, only few have been using this due to its price being costly. Using solar power is also a great form of investment because it will provide more benefits in the long run (in terms here, for the miners/farms of BTC).
If you are trying to say that massive energy consumption by Bitcoin mining will drive energy prices up to the point that renewable energy will become cost competitive then... maybe.
So basically burning through all of our non renewable natural resources will cause us to switch to renewable sources of power.
Your point really has nothing to do with whether or not Bitcoin mining is using "too much power".