A huge amount of research has gone into it. We reckon that about 90% of homes in the UK are suitable for heat pumps. Obviously, there is a wide variety of different homes; the area that the noble Lord and I come from has a lot of terraced properties. You can use ground source heat pumps with common arrays in the road, and you can use heat networks that have one remote location powering the heat pumps. There are a number of different technologies where this is perfectly possible.