[quickthrowman]

There are district heating and cooling in cities where it makes sense, both Minneapolis and St Paul, plus the University of Minnesota all have district heating and district cooling systems. The Minneapolis and U of M systems are operated by Cordia Energy and the St Paul system is operated by Evergreen Energy.

This is the coldest large metro area in the lower 48 states, so it’s economical to do district heating and cooling here.

[zdragnar]

These heating districts don't cover a very large area. It's impressive in its own right, but if you're using them as an example, it just shows that it only works at very specific scales.

[quickthrowman]

Agreed, you need a fairly dense concentration of buildings with heating and cooling requirements in the tens of millions of BTUs per hour for it to make economic sense.

[trollbridge]

Right, but quite a few of such places do indeed exist (and new ones are being built).