While I do love the concept, it is not very feasible at the scales this company is talking about. It's mostly used in huge recovery systems for things like geothermal systems, or small capture recovery from industrial sites, but if they manage to find new ways to concentrate this kind of heat capture, it could get interesting.
My initial thought goes to using datacenters as sources. Tons of heat production, but you'd need to concentrate that in order to capture it somehow. Like large scale radiators that connect to each other to pipe captured heat to a central location or something. Would serve a dual purpose of cooling and capture.