This is basically going back to the old way of heating homes: When energy is cheap, heat a giant thermal mass. When energy is expensive, leach the heat to other areas where it’s needed.
In the old days this would be a giant brick or clay stove that would heat up during the day (when people are awake to tend the fire) and radiate heat to keep the building warm through the night.
I’m the modern version it’s likely steam pipes heated by the mass that bring the heat to wherever it’s useful (whether that’s an industrial kiln or a home’s radiators). That cycle can be extremely efficient, but you obviously only get heat, not electricity.
It’s probably a good thing to do in some contexts but if I understand it right I’m not sure I’d call it innovative.