I’ve been thinking about Combined Heat and Power (CHP) as a solution to the energy crisis.

The idea is to generate electricity anywhere you need to generate heat, in effect saving the waste heat of electricity generation. It works best in cold climates, but would work quite well in southern Australia if you have grid interactivity. It
would be a nice complement to solar thermal, because it generates more power at night and during winter.

The exact same principle could be applied to water heating. By a rough calculation, 700 kWh of gas can heat about 15000 L of hot water for about $50, and allow you to generate $45 worth of electricity for another $20.

I don’t have any figures, but I would expect that a high proportion of piped
natural gas usage by both industrial and domestic customers goes into low
temperature heating of one kind or another. The main exclusion is high
temperature heating like cooking and industrial furnaces.