You make a claim about reworking our economy,
> The power is cheap enough that it's worth reworking our entire economy around it.
Can you substantiate this? Would it be fair to describe it as a utopian claim?
In the case of water heating (and water based space heating also) it's already here in terms of technology and availability. Heat pump storage water heaters are now widely available. The problem is that they can only be phased in as fast as existing gas water heaters reach EOL.
Domestic water heating comprises almost 18% of household energy use in the United States.