[thyristan]

Steam and hot water pipes are extremely expensive to install, far worse than electricity, fibre, water or sewage.

You need to be more leak-proof than cold water pipes, because loss of pressure with steam and hot water is much more of a problem than with cold water and cannot easily be solved by just adding more cheap water. Pipe materials have to be more resistant to corrosion because higher temperatures and pressures make them corrode so much faster than with cold water. Closed hot water/steam circuits also mean that there won't be a protective limescale coating on the inside. You need insulation that you can bury and which will last for at least 40 years, which is even more expensive than the pipes. And the insulation will double the pipe diameter. And the insulated pipes have a larger keepout area that needs to be kept free of rocks, other pipes and mechanical strain because the insulation is soft and sensitive to those things. Since usually the pipes aren't operated in summer, and since generally thermal variance is far higher than with cold water, thermal expansion needs to be taken into account, so you need expansion corners, sliding sections, different valve constructions that are tight in all temperatures, etc.

And even with perfect insulation, you will loose approximately 30 to 40% of heat in your piping. So all of this is only viable if you don't care about the cost of the heat, your consumers can (be forced to or persuaded to) accept at least 30% higher prices per kWh compared to their local boiler, not to mention the capital cost.

There are only some areas in Europe even, where those kinds of installations take place: Densely packed inner cities with largely rented-out flats in appartment buildings. There, the landlords/owners avoid the cost and risk of a local boiler and don't care about the running cost of heat, because they don't pay for it. In smaller towns, like in the example, mostly public buildings like schools use those kinds of district heating systems, because the municipality doesn't care as much about cost of the heat, and more about cost of maintenance of a hundred local boilers vs. one centralized system. And in the end, it's taxpayers' money, so they don't actually care that much, headlines and opening ceremonies are more important than that.

Individual home owners usually do have their local systems, which can be run cheaper than what district heating will charge you. And since city density is lower and home ownership is more widespread in the US, district heating is even less competitive there.

[jabl]

> And even with perfect insulation, you will loose approximately 30 to 40% of heat in your piping.

At least here in Finland the norm is losses in the range of 5-20%, with the upper end of the scale for smaller scale networks with smaller diameter piping and low flow rate. In the larger cities losses are closer to the low end of that scale.

In the summer when the consumption is very low (essentially only hot tap water production) losses can rise up to 50%.

[adgjlsfhk1]

lots of industrial processes produce waste heat that can't easily be turned into energy, so the comparison isn't to a boiler, but to not having the heat.

[thyristan]

It is true that the heat can be used if it is there anyways. But usually not in a big city-wide network. Instead a more localized, larger consumer is far better, because running the hot water network is far too expensive. For example, large producers of heat like data centers, dairy processing or chemical plants around here deliver their heat to public swimming pools, schools or greenhouses that are intentionally built nearby.

Even the grandparent's article says so if you read carefully: "A large portion of the town’s own buildings, including the municipal school, town hall, and library, are connected to the district heating network.". They didn't even attach all of the public buildings. Not to mention about the rest of the town.

[trollbridge]

That's exactly what I was thinking of. Cogeneration plant goes up right next to datacentre, and then various municipal services are built near that - including other factories, high density commercial and high density residential that can take advantage of cogeneration and use district heat. In particular commercial and industrial uses actually do need heat in the summer.

In some areas, natural-gas fired cogeneration only is really necessary in the winter during dark months/cold weather - which is an ideal situation to be producing district heat.