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Combi dilemma!


DamonHD

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  On 12/02/2024 at 18:39, SteamyTea said:

Have you seen Mr. HD's beard, she will put up with a lot.

(when I visited the IWI was being done and there was a baby somewhere, heard it, never saw it)

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You haven't seen my hair recently!

 

Baby?  I knew I'd misplaced something behind the IWI...

 

(The older one turned 18...)

 

Rgds

 

Damon

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  • 6 months later...
  • 1 month later...

On Monday I had a pre-installation visit to discuss details of trenching and other prep works, for a planned install next month.

 

We often don't put our heating on until December, so I may have already done my last space heating with gas in this house.  Consumption has been tiny since April: https://www.earth.org.uk/saving-electricity-2024.html

 

I am developing a scheme for re-integrating the Sunamp and Intasol with the heat-pump DHW which I think might work well (treating the DHW cylinder as if it is a combi in this arrangement, with the DHW cylinder being 1st priority for Eddi diversion/boost output, Sunamp 2nd),

Edited by DamonHD
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  • 3 weeks later...

Management of how these are being delivered by Octopus seems to gotten worse rather than better over time 

@DamonHD - is the crew employed by Octopus or are they over-promising on sales and hoping to backfill delivery capability by subbing out 3rd party installers without a management structure to operate in this manner?

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Everything seems to be working nicely.

 

I have captured current settings/configuration.

 

I shall do some tweaking over the next few days.  Nothing major by the looks of it, certainly less than I had expected.  One thing that I wanted to do does not seem possible (schedule/clock AND external call for heat) but I can live without it, as the external call is reasonably well-behaved.

 

https://www.earth.org.uk/heat-pump-16WW-control.html

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  • 2 weeks later...

If at some point the current grid intensity is less than half its average over the last week, then I am claiming that filling my storage boots now is the same as (in CO2 emissions terms) using the heat pump with a CoP of ~2 at some random point during the last week.  Similarly looking forward a couple of days.

 

We are all aware (eg including @Ed Davies!) that there is some contention about that reading, though maybe less so now that constraining excess renewables for reasons other than transmission is becoming more of a thing.

 

In any case I take very low relative grid carbon intensity (and no drawdown from grid storage, aka "supergreen") to be indicative of abundant low-carbon generation and minimal strain on the transmission and distribution system, so a good time also to fill boots.

 

How should I have worded those paras better in my talk?

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  On 13/12/2024 at 18:33, DamonHD said:

How should I have worded those paras better in my talk

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Ask your Dad, he is very good at science communication.

 

Failing that,

  On 13/12/2024 at 18:33, DamonHD said:

If at some point the current grid intensity is less than half its average over the last week, then I am claiming that filling my storage boots now is the same as (in CO2 emissions terms) using the heat pump with a CoP of ~2 at some random point during the last week.  Similarly looking forward a couple of days.

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You said what I thought you meant, just needed that extra bit of clarification as you are showing that using one technology, with a CoP of 1, and, in some circumstances be thought of as equivalent to another technology with a CoP of 2.

 

  On 13/12/2024 at 18:33, DamonHD said:

We are all aware (eg including @Ed Davies!) that there is some contention about that reading, though maybe less so now that constraining excess renewables for reasons other than transmission is becoming more of a thing.

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Yes, this is a problem as we introduce more weather based generation.

It is interesting to look at the phase out of coal generation, some days coal only produced into the grid for a few hours.  While this looks good on the reporting, those power stations were still burning coal as they cannot go from zero to almost 1 GW in half an hour.

What is known as hot spinning reserves or in the case of the zero periods, probably just spinning reserves.

Wind is probably, at the moment, doing the opposite i.e. overproducing and has to be curtailed, sometimes, to allow the larger gas plants to reintroduce power in an orderly manner.

 

image.thumb.png.0a285145c2bc0b190a2f35d6e4562e00.png

 

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Our overall electricity demand curve this month up to yesterday shows some successful load shifting for DHW at least:

 

https://www.earth.org.uk/heat-pump-16WW-control.html#2024-12-20

 

Load profile over 2020-12-01 to 2020-12-19 inclusive, gross and net/imported. DHW consumption spikes starting at 07:40 and 19:10 are clearly visible.

 

bucketed.202412-01to19.all.png

Edited by DamonHD
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  • 2 weeks later...

This is my favourite chart at the moment.

The big drop 3 years ago was the secondary glazing I added to my double glazing, making it triple glazed.

Getting harder to use less now.  There is a load of PU foam boards at work which I intend to have away to add to my loft insulation.

 

image.thumb.png.776ac6527c8ca576e67ddde0db5d770a.png

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  On 01/01/2025 at 21:03, SteamyTea said:

This is my favourite chart at the moment.

The big drop 3 years ago was the secondary glazing I added to my double glazing, making it triple glazed.

Getting harder to use less now.  There is a load of PU foam boards at work which I intend to have away to add to my loft insulation.

 

image.thumb.png.776ac6527c8ca576e67ddde0db5d770a.png

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Nice work

 

Here's my favorite

 

From top to bottom

 

Elec kWh for 2019 to 2024

Gas kWh for 2019 to 2024

HDD data for 2019 to 2024

 

Bloody labels disappeared for some reason!!

 

GasElecandHDD2019to2024.thumb.JPG.834592ea56a9717263b993d6b720e924.JPG

 

Yes 2024 is an increase on both elec and gas but electric was driven by my hobby (welding takes a fair chunk of electrickery) and Gas is a result of going 24/7 this heating season.

 

Data For a 113 m2 (290 m3) 4 bed 2 storey detached house with 2 occupants (one of which makes a lot of noise if it's cold)

 

Oh and just to say when we moved into the house in 1991 we were using 25,000 kWh of gas a year - but the house had single glazing throughout the house, 25mm of loft insulation, no jacket on the uninsulated copper HWC and a non condensing glow worm boiler from 1982 that needed to run at 80 deg on the flow temp all winter to allow the 10 undersized T11 rads to be able to get the house warm..........

 

Now I'm running 30 deg flow temps at Zero outside!!!!!

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  On 02/01/2025 at 16:13, marshian said:

when we moved into the house in 1991 we were using 25,000 kWh of gas a year

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When I moved in 20 years ago, I was using around 11,000 kWh/year.

Been slowly reducing it most years, even when I had a lodger (once trained) my usage did not increase too much.

 

What base temperature did you use for your HDDs?

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