alt Hacker NewsThe cost of batteries has gone down somewhere between 60-80% over the previous 10 years (and my understanding is that trend is expected to continue due to a combination of new technologies (e.g. Sodium Ion) and increased scale). So that one seems totally reasonable. A little conservative if anything.
I can't comment on the cost of Gas Turbines.
No one believes that the increased demand for gas turbines is durable enough to want to make those kinds of investments.
But the opposite is true for batteries.