There always will be fringe markets for products that use renewable energy to provide marginal heating comfort. These markets survive based on “early adopters” or carbon minimalists who willingly sacrifice superior comfort as the perceived “price” for using renewable energy.
One of my assertions, learned over 40 years of working with a range of renewable energy-based heating systems, is that they will only gain mainstream acceptance if they provide comfort that’s as good if not better than conventional systems. The typical North American consumer will not knowingly sacrifice comfort just to shift the source of their heating energy from conventional to renewable sources.