Well, water ain't free (and it will be more expensive in future)...

Well, water ain't free (and it will be more expensive in future) and electricity will never be either

It depends on how you define "almost free". I'm still monitoring my solar feed-in and electricity usage in my new house, but I'm on target for $0 in bills for the year, and maybe even a small profit. It was expensive to set up but right now for me electricity is indeed "almost free" already. If all goes well I'll never pay another power bill. Other posters here have reported similar circumstances.

I'm also quite interested in rainwater harvesting. Tanks (unlike solar panels and heat pumps) are fairly cheap, and I've added 8,000 litres of storage to the 3,000 required by the NSW government for new houses. Yes I do pay for town water, but the average price gets lower when you use as much rainwater as you can, and it is approaching "almost free". But it is more expensive than electricity for me.