Among the potential solutions, he doesn't mention reversible computing, which I found weird, because the whole point of reversible computing is drastic reduction in power draw.
Maybe he doesn't think it would ever be fast enough, or maybe he thinks it can only apply at really small scales (i.e. nanotech) and there's no smooth incremental path there from where we are now?
We're a long way from needing reversible computing, silicon isn't going to get us anywhere near the theoretical efficiency the universe allows us in non-reversible computing. Maybe after we transition to photonics or ballistic electrons or DNA computing or something and plumb that technique to the limits of it's efficiency we can worry about reversible computing. In the mean time, we really only know how to make good computers out of silicon and dark silicon is really only a concern in a silicon context.
Are there any conceivable practical ways to implement reversible computing? I think it makes sense not to mention ideas that are super hard to fulfill.
Maybe he doesn't think it would ever be fast enough, or maybe he thinks it can only apply at really small scales (i.e. nanotech) and there's no smooth incremental path there from where we are now?