Miniscule % of people have heat-pumps. In UK most people use either a gas boiler or a dumb electric heater. And you can't even install heatpump in an an apartment building without re-constructing half of it.
Today that is true, but I think the trend will move towards a larger share in the future. Relevant anecdotes:
- All newly build housing in the Netherlands must be without natural gas, thus either lower heat-grid or heat pump heating
- People that use airconditioning for heating have a heat pump without being aware of it (if configured that way)
Finally, for any technology early in the adoption curve, the market share - or even the growth rate (%) - today shouldn't be taken as good indicators for future development. E.g. McKinsey famously underestimated the mobile phone market by 100x that way [1] and the energy predictions on the adoption of solar manage to underestimate installed solar power _every_ year. Instead, also consider growth-of-growth and network effects as adoption grows.
They are slowly becoming more common here in Germany. I'd say about half of the houses in the newly developed part of town have one and a few older ones are retrofitting them as well here.
