Very good article. I plan to go down that rabbit hole within the next year or so.

Why don't you try using the compost heating method of Jean Pain of France, to pre-heat your household water before boiling/ bathing or keeping your outdoor water ice-free? You can even try burying pipes into a large compost heap or using heated plastic greenhouse air to circulate through with a CPU fan on a thermostat for heating the home.

I also love being creative and thinking out of the box to make things with your own hands. All the best!