Looks like the biggest obstacle to going off grid is the amount of energy used for space heating.

So, what about low flow temperature water radiators?  Most radiators need to run at high temperature but these beasts use the same temperature as hydronic systems while preserving the footprint of a traditional radiator

https://www.mesh-energy.com/low-flow-temperature-radiators-the-next-best-thing/

 

There are a couple of mainstream radiators on the market that fit the bill and allow underfloor flow temperatures to heat a room whilst retaining the same ‘wall print’ size as a traditional radiator. Low flow temperature radiator designs take advantage of compact but highly efficient multiple small bore pipe and a lightweight aluminium fin design to maximise the area emitting heat as well as the option for convection fans to boost output.

 

I see that there's a supplier of such systems in Naenae so will go to have a look.  But potentially maybe one could hook this up to thermodynamic panels and end up with very low cost space heating?