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.
Yep, that's why I drive a big block Chevy with Hilborn mechanical injection, because I care about environment. With all them fuel-efficient cars around, we'll never switch over to clean, renewable energy.