A map of places suitable for water source heat pumps has recently been published.

The idea that areas where there is high heat demand are close bodies of water and could therefore be suitable for district water source heat pump schemes may see a good one.

Warnings:-

District heating though popular in other countries have been very unpopular here in the UK.

High heat demand should be reduced in the first instance.

Taking vast quantities of heat out of bodies of water, especially rivers and lakes could result in them freezing!

Water source heat pumps need licences in order to use the water and the authorities responsible for these can put up a lot of expensive hurdles to overcome in order for such systems to be allowed.

Who owns the right to the heat in a watercourse is as yet undetermined in law, can I for instance take more than my fair share of heat out of my local river leaving my neighbour down stream at a disadvantage (this is akin to shading someone's solar panels with a new building).

Water source heat pumps, though very efficient, will loose some of their benefit if used to power a heat main.


To sum up we would do well to reduce our heat demand and we still are not paying anything like enough attention to this aspect of our energy policies.

Posted By: tonyWho owns the right to the heat in a watercourse is as yet undetermined in law

How close to a river bank can you put a ground source heat pump without needing any sort of abstraction licence? Say if you have a river or stream running along the edge of your property. I don't but I know people who do.

Posted By: Ed DaviesHow close to a river bank can you put a ground source heat pump without needing any sort of abstraction licence?

Probably quite close as the water tends to run from the land to the river/stream.
The large power stations that extract river water for cooling are only allowed to put it back once it has cooled to just about the extraction temperature. They are probably limited to the same flows as any hydro scheme is (I learnt the rules once, based on the 95th percentile and then a limited flow or something).
https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/380362/LIT_8836.pdf

Down here we could use the sea, but the pipes would need to be a long way out because of the tides, then piping around a town would be costly.

Posted By: Ed DaviesHow close to a river bank can you put a ground source heat pump without needing any sort of abstraction licence? Say if you have a river or stream running along the edge of your property. I don't but I know people who do.

Is an abstraction licence only needed where water is actually draw from the river, passed through heat exchangers on land, then returned (akin to run of river hydro)?

A water source heat pump that simply involves coils in the river (& any GSHP, no mater how close to water) is only abstracting heat, not water.

Perhaps that's the difference? Otherwise any GSHP in ground with a high water table could potentially be caught up.

New flats on Bristol's floating harbour are heated by a kind of district heating.

The management company buys gas in bulk on the open market.
That gas runs a turbine and generator to produce electricity.
That electricity provides resistance heating and hot water to the flats, each flat is metered for heat used by a normal electric meter.

They flog it as money saving but I can't believe that makes sense?
A heat pump taking heat from the water of the overlooked harbour or nearby river would surely have been much better?

Yep, funny that. Flat I shared in Holland [¹] had shared heating for the whole block. Can't remember much about it - think it was a big gas boiler in the basement with some sort of heat meters in the flats - obviously wasn't an issue.

Re the Bristol system Sprocket describes: it could make sense if the gas turbine thing is a CHP plant which supplies both heat and electricity to the flats.

Trying to stay on topic: district heating ought to make sense as it allows a) interseasonal (or, at least, longer-term) heat storage and b) much more flexibility of heat source including solar, “waste” heat from electricity generation and also water source, particularly in a harbour. You could imagine a CHP system which stores heat in a heat store when electricity demand exceeds heat demand but uses a heat pump of some sort when the heating required is greater (and the heat store is empty).

[¹] A while ago; I moved out while the British fleet was on its way down to the Falklands.

How do you change your energy supplier if you have a district heating system?

I can see some efficiency gains, but I can also see a lot of abuse from both users and suppliers.

How much of that is down to being a 'freehold' nation compared to a 'renting' nation I don't know.

Posted By: ringiThere are a few issues with district heating systems…

Cooler the flow from a boiler, more it condenses, but a DH system has to be hot enough for all uses.
With heat pumps it is even more important to keep the flow temp as low as possible.
There are high fixed system loses regardless of the level of demand for heat.
If you have mains gas, a gas boiler is hard to beat.

So I only see DH working well when the heat is a by product of some other process, or burning something that is hard to burn at home….. The heat must have a cost close to 0, for it to be worth while covering the cost of the DH system to move the heat.

Without knowing the economics of installing and operating the district heating system, which I imagine is difficult for the average person to know as they're by definition not something you'd install at home, any opinion on their relative economics must be little more than conjecture.

Just been thinking of this as a friend of mine lives in one of the new Bath Western Riverside flats that is on such a system. He says he's barely had to use the heating as the insulation is so good. You can see one of the blocks here: https://www.google.co.uk/maps/place/Victoria+Bridge+Rd,+Bath,+Bath+and+North+East+Somerset+BA2+3EH/@51.382068,-2.373744,3a,75y,358.41h,88.82t/data=!3m4!1e1!3m2!1s58bBbeOrOP_MX5a14yoxqQ!2e0!4m2!3m1!1s0x4871813ed0074dab:0x682d2b0b3a4c13d6, but they are building a lot more like it.

Ed