I was interested to learn about cold district heating recently, which is basically a municipal scale geothermal system.

https://en.wikipedia.org/wiki/Cold_district_heating

I went to Moscow in December several years ago and learned they've got one the world's largest district heating systems.

▲

xattt 5 hours ago | parent [-]

I am not sure if this is still the case, but up to 20 years ago, these were typically shut off in May-June to August for “maintenance” which resulted in a prolonged period of no hot water in apartments.

	▲	lstodd 38 minutes ago \| parent [-]
		In Moscow? Never. It's been usually a month in soviet times, two weeks max nowadays, usually sometime in late June - early August. edit: also on heating question - Moscow's electricity is provided by 40 or so big gas-fired steam turbine generator plants, about 10GWe total. District heating serves as cooling for all this power generation.