Kinda seems like a similar idea to the solar heating that Drake Landing in Okotoks Alberta has. Had a heat xfer prof in uni who was really passionate about that project in particular, and this was back in 2007, really don't know why solar district heating like this doesn't really seem to have caught on, afaik it works well.

Edit. I'm ootl, apparently that got decommissioned recently which sucks, was a really interesting idea, guess I have my answer as to why they didn't catch on! It lasted far beyond the 4 year test period and supplied a large amount of the community's heating needs, it's cold in the winter in Okotoks so that's even more impressive to me.