[matsimitsu]

I happened to get a tour of our geothermal district heating building last week, it was really interesting.

The entire neighbourhood of about 2200 houses is heated and cooled by this installation.

About 60% comes from the heat pumps that get their water from two well pairs, about 40 and 80 meters deep. It's not a closed system and the ground water flows about 50-100 meters to either pair.

The remaining capacity comes from a gas turbine that generates electricity to sell back to the net, and the residual heat is captured and used to heat the district. If the demand isn't there, it's pumped back into the ground for future use.

The third method is what amounts to basically a giant electric kettle, which has the worst COP factor, but there are times here in The Netherlands when energy prices are negative, and that's when they shut down the gas turbine and use the electric heater instead.

There are three pipes going to every house in the district, one with hot water, about 70 degrees and used for both floor heating and hot water, one with cold water for cooling in the summer, and a return pipe.

It removes a lot of infrastructure from your house, the hot water goes directly in your floors, so no boilers or furnaces. There's a small heat exchanger that warms the tapwater for showers, and you have zero maintenance.

[Gravityloss]

EDIT: it seems also in the original article and also in your comment it's NOT geothermal, it's a ground heat pump.

[crgwbr]

A geothermal heat pump is a common name for that type of system.

[gniv]

That's pretty amazing. Is floor heating enough in the winter? Can you turn up the temperature if needed? In the house I am in right now the floor heating is not enough, they had to add radiators. All electric.

[matsimitsu]

More than enough, but they are all new houses and have great insulation (Triple glass everywhere etc.)

[Thlom]

Would be more efficient to add a air-to-air heat pump rather than pure electric heating?

[uptime]

That is amazing. I would have made a special trip to see that - I just got back from NL. How involved is it there to get the new pipes into those homes? If you could supply any URLs or geo clues I’d appreciate it!

Edit: was this a new from scratch development or a retrofit? I realize my plumbing question might be irrelevant.

[benj111]

>about 70 degrees and used for both floor heating and hot water

Underfloor heating? Is that not too hot to walk on???

Or is some kind of in-house heat exchanger used?

[Loic]

Two heat exchangers, one big for the hot water, one smaller for the heating. Heat comes in the form of water at 10bar/75°C. Everything is packed in a box having the a size of 1m (H) x 50cm (L) x 30cm (D). Isolated delivery pipes are all under the city block.

We have that at home, this is great. No noise, no maintenance, no emissions. The only downside is that you are "locked in" with a single heat provider.

[wernerb]

The hot water probably gets mixed with cold at the manifold, you do not put 70 degrees water in your floor.

What i dont understand is how it is efficient to deliver a constant 70 degrees heating pipe. There has to be some kind of boiler/trigger right?

[matsimitsu]

It gets mixed with water already in the floor, adding just enough to maintain temperature. (in my case 30 degrees)

[agumonkey]

For people living in high insolation, do you use black water tank on roofs for heated water ? if not why ?