Trys are 5 points now.

I'm booking my ticket now.

A fairly standard municipal pool will be about 25mx10m by an average of about 2m deep

So about 82ft x 32ft x 6.5ft and the electric will probably be between £0.50-£1 a kwh depending on their contract, and it's all year round, and the article said the £300k was to heat the complex so presumably includes changing rooms and offices etc but the pool will be most of it.

This one is the size of a washing machine and can heat a municipal swimming pool 60% of the time, it currently costs around £300k a year to heat a pool in the UK, which is around what 300 houses worth of central heating costs.

Even after allowing for an order of magnitude difference in efficiencies between heating a body of water and homes you wouldn't be looking at huge amounts of space.

Finally a bit of joined up thinking.

Now can we use this on a bigger scale for district heating?

If they're not rotten they'll be fine, you can always give them a slap of anti rot stuff to be sure, especially on the ends.

"One day every major city in America will have a telephone"

Alexander Graham Bell.