The thing is, it is not going very well, at all.
Originally, they said they would need about 150 households to sign up, to make it viable.
Then, dropped that to 130, and now, there are only 15 households, who have signed a contract.
Many are very nervous of the project, and it’s ability to provide the stated heat, as well as the pricing.
They will go ahead, and we have signed up, but it is chaotic in many ways, but this is the only way we can afford to try a greener energy policy.
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Friends of ours in the village installed a ground-sourced heat-pump a few years ago - at an optimum point for grants &c, and - setting aside capital costs - it has saved them a fortune in heating bills. Their house is a 1940s 4-bed semi, but fairly up-to-date in terms of insulation and doors/windows, the GSHP heats it more than adequately for about 95% of the time - and that’s with a 95YO relative ensconced there at a steady 25C!
I appreciate the pros/cons, but it can work-out very well, so fingers crossed - you guys are evidently guinea-pigs for this scale of project 
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That is why yhey are pushing ahead. We are the guinea pigs for the country. This is the first community based ground source heat project, in the country.
There have been a few projects, on smaller housing estates, but nothing that covers this large span of pipework.
There are already a number of communities that have contacted the organisation.
The top up boiler is electric, and not powered by solar, which is a shame. But hopefully, they will make it work.
On another note, I asked my plumber, about the possibility of keeping our existing system, for awhile, and putting in a switch network, to let us manually switch between the systems, if needed. He said it was possible, but probably impractical. He added, that he had removed a air source heating system, from a large house, because it was too expensive to run??
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4 posts were merged into an existing topic: Best of Local News
It’s interesting that the government doesn’t see either ground source heat pumps or indeed tidal power as part of their plan for Net Zero. Presumably because the fossil fuel companies aren’t behind either approach.
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As a result of the aforementioned project, at least a dozen people in the village have had air source heat pumps installed. The promise of getting your money back, was too much to resist.
The fact that they are just air conditioners in reverse, doesn’t seem to have stopped them.
Ever seen a cheap to run air conditioner?
Well … it depends what you’re comparing it with. If you compare a heat pump with direct electric heating then joule-for-joule they should be a lot cheaper to run.
The devil is in the detail of course. Direct electric heating can supply a lot of power, and at high temperature too. So it enables rapid warming, which means if you’re out all day and in bed all night you can leave it off for much of the time. Nothing is as cheap to run as a switched-off thing. Heat pumps of any kind struggle with this.
The real problem is gas is very, very cheap.
An air source heat pump, is not exactly going to supply a lot of heat, quickly, is it?
As they work on lower temperatures, often radiators have to be upgraded, as well.
Even running a dehumidifier, is just an airconditioner, in reverse, and not cheap to run.
The ground source system is supposed to provide us with a minimum of 70º, but generally 75º. They are going to drop it to 60º for three months, during the summer.
That’s what I said, implicitly. Direct electric can, heat pumps can’t.
There are some high temperature ones around now. However the first part of installing a heat pump is to insulate your house as much as possible.
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With regard to most systems of measurement I can happily work and think in either format (lbs/Kilos, Inches/cms) but with regard to temperature I now find fahrenheit meaningless, I have to convert to celcius to understand what those numbers mean.
I have no idea when this happened!
I’m the other way round. My entire student and professional life - the last 45 years - was spent in SI i.e. metres, kilogrammes, Kelvin (Celsius with 273 added). But if I want to judge how warm the day’s going to be I do that in Fahrenheit - below 40 is cold, 40-50’s cool, 50-60 is in between, 60-70 is fine, 70-80 is warm/hot, over 80 is properly hot, over 90 is too hot.
I do wonder if heat-pump engineering has anything like the scope for development that solar (for instance) does? The more science-y feeds on social media have seemingly-endless articles about the latest innovations in complex perovskites, new formulations, molecular-scale engineering of them, new substrates, &c &c … Seems to be huge amounts of research underway - the vast majority in China it’s worth noting.
Without any technical knowledge, I wonder if you are going to hit the sort of expansion/contraction limits on thermal efficiency that are applicable for combustion.
The viability of these appears to largely constrained by insulation levels of the property they’re installed in. As in your example up the thread, in a well insulated house they are great.
In my drafty, solid wall shitbox, not so much.
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The big problem for the ground source heat system, is there is no " turn it up " ability.
If the system can’t maintain the heat, or you are not warm enough, you can’t " turn it up ".
My boiler works on 70º, but if it is not keeping the house warm enough, I can turn it up.
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With heat pumps we really are quite hard up against the thermodynamic limit, which is maybe not surprising given that we’ve understood thermodynamics since the 19th century and been sweating every last drop out of heat engine efficiency since then.
The best coefficient of performance (heat out of the pump divided by electrical input power) would be Th/(Th-Tc) where Th is the temperature of the fluid at the output (say radiators) and Tc is the temperature of the heat source (say the outside air, or the ground), all temperatures in kelvin of course.
If we wanted hot water in the rads at 50C (323K) and the cold air was close to freezing 0C (273K) then the theoretically best coefficient of performance would be 323/50 = 6.5 or so. And to get that we’d have to eliminate every possible loss in the system completely - so frictionless bearings, 100% efficient electric motors, perfect insulation and perfect thermal conduction where those were needed, no viscosity in the working fluid, no regions of thermodynamic non-equilibrium anywhere etc etc.
To be honest I’m surprised that commercial heat pumps are as good as they are. But I’d bet a tidy sum they aren’t going to get 50% better any time soon.
When I was last working on solar panels (around 2000 or so) commercial ones were at 15-20% of the maximum theoretical performance. You could do a bit better if you used curved mirrors to focus the sun onto them, but there might be consequences for their lifetime. If you had NASA’s budget and wanted the best possible, to power your Mars rovers in weak sunshine, you could get 35-40% IIRC.
So there was a factor 5-6 headroom left for commercial solar cells. I fear there’s not much more than a factor of 2-3 left for heat pumps. And the latter have moving parts.
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Saw a guy on the telly who’s company has been installing heat pumps for a long time and he is well versed on the current crop of equipment. He said that if the air temp was 4C then the rad water temp would be 40C………… you are going to need a very well insulated house for that to be any good.
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And massive rads
Even underfloor heating will be struggling with a 40 degree feed unless there is a lot of pipe
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Yeah, doesn’t look too good really. Might need to open up that old fire place and get some coal in……
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