It seems so difficult to use energy without converting it but is that because it’s simple? The simple way to collect, store and redistribute heat is to use a thermal-fluid instead of water. These don’t boil or freeze from -40C to 280C, for homes they are non-toxic and food-contact rated so allow storing more heat in less volume than water in a collector, a sketch of a fixed-angle unit below.
To store the heat it’s best using a set of nested tanks, both insulated and the high heat leaks to the second tank that’s used to distribute heat to the house. So with insulated hoses pulled in walls you use a heat-exchanger in the rooms and this is about 10-times more thermally efficient than using air and usually called ductless heating.
Then even on a cloudy day heat is bounced back from the clouds and a low heat can be relied upon to keep a home warm enough but a backup system is there for the few times it’s not. This is a big deal for homes to have a rather natural, daily way to gain and store heat that will last all night. Then with collectors you can store enough heat for hot-water and laundry along with keeping the home warm, this becomes a great savings in a short time as the previous costs are greatly reduced.