@robl Many thanks for the info, I've got the PDF and only had a quick scan but am totally in awe! What a project. 
A monobloc ashp  would certainly be easier! I'll study it later when I've got some time.

One very minor question, unrelated really, on P3 of the PDF there's a graph with a 'best fit' dashed line. Did you do the line visually or with software? Just that I'm looking for some software to do that job on some EV data I've been compiling these last few years.

@geo3geo 

That graph I did is in excel (I think version 2006), using the best fit line it has built in.  You can select linear / polynomial / lots of other types from a + symbol at the top right of the graph.  Frustratingly every version of excel moves options like that around, but it's always in there.  The indoor & outdoor temperature data came from a logger I made (!) and gas use downloaded from Ovo that we were with at the time.

Posted by: @robl

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ASHP benefit from the vast amounts of R&D money and time spent on almost identical air conditioners, which are prevalent around the world.  In contrast I'd guess gshp have 1% of the research spent on them.  

The groundloops or boreholes for gshp are time consuming or costly to drill or dig.

I'm in general agreement with these observations.
However, there are shortly to be changes in British energy strategy and regulation, which could work in our favour if we 'get involved'.
More in a moment...

Let me pick up each of these points and expand on them slightly.

1: ASHPs tend to be built from the same standard components, sourced from manufacturers in the Far East.

The Western pseudo-manufacturers build these into an enclosure.
Then they add their own controller (& sensors), and create an App.
The result is that you get 'tied in' to a control strategy, rather than being able to see which 'manufacturer' has procured the better-quality components in the first place.

But we can readily discover the Far East component manufacturers for ourselves, and hence build a DIY ASHP.

OTOH there are pretty few generic components to DIY-build GSHPs at the output level we require for a typical British home.
Let's say that's a HP with an output between 10-15kW.

This Forum might be able to overcome that.
There are people here who could investigate the market for available GSHP components and publish them here.
Common starting points are Alibaba and Made-in-China (but not for the next fortnight because they've just started celebrating the Chinese New Year!).

2: Yes, it's the excavation costs which add significantly to the installation price of a GSHP.
That's holding back their adoption, despite there being a number of geological formations in GB for which they are well suited.

Few homeowners have a spare hectare to lay slinky-pipework in trenches 1.5m deep.

And the costs of a drill-team are high because the same air-flush drill rig can also be used for more lucrative work, stabilising embankments and grouting old workings which underlie houses, for example.

So if we want to have more GSHPs here, with COPs around 4.0, then 'someone' needs to specify the strategy and get it implemented.
If such rigs were only ever going to be drilling 150mm diameter boreholes, then we can save money on the highly-competent geologists who usually operate drill-teams. A multi-purpose rig can also be pared down and equipped solely to drill boreholes.

Fortuitously, Future Energy Strategy, Operation and Planning is being devolved into the hands of an Independent body (ISOP) supported by Regional Energy Strategic Planning organisations.
Together, they will have the resources and the clout to make the necessary changes. We discussed ISOP and RESPs here and in several other Topics too.

The remit of ISOP is to implement what's required for GB to attain Net Zero by 2050.
They need to evaluate all the possibilities, and then ensure we have a mixed-energy economy which adds resilience to the system.

One possibility is to incentivise Social Housing Associations to install GSHP energy-hubs suppling several of their houses at once.
That facilitates cheaper domestic heating for the poorer households in GB.
Social housing tenants are more likely to be on pre-payment meters and be suffering from energy-poverty.

And at this point I'm giving myself a rebuke for straying wildly off-topic...
... because it's actually battery storage which is much more my speciality than heat-pumps!

@robl Thanks for Excel info, I use OpenOffice which doesn't seem to offer this. I'll use my wife's MS suit!

@transparent << incentivise Social Housing Associations to install GSHP energy-hubs >>

What a brilliant idea. Sadly we aren't even mandating PVs on new builds so a major change in planning is reqd.

And thanks for the excellent gshp overview you provided.

Posted by: @geo3geo

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I'm thinking about the possibility of a heat pump but first I'm looking at getting lower running costs. And to make a huge hole in the running costs, powering it off cheap night rate electricity would seem an obvious winner. It seems that what I need is a battery system that can be set to charge for a set duration at night, plus soak up any excess electricity from my existing PV system. Then whatever needs mains electricity, like a heat pump, can take it from the battery via the grid using the battery's inverter-charger unit. I think I've sourced a suitable battery system but would really like feedback that I've not missed anything. It seems too sweet to be true. Is there a catch? What I'm looking at is 

Triple Power 6.0kWh + X1-FIT 5.0kW Battery Bundle £3840  from TheEcoSupermarket.co.uk. 

Any other suggestions appreciated.

A few ancillary questions:

1. Such a system would mean I'll be exporting very little to the grid so would I still get my generous 10 year old FIT payment? Seems a steal really. I get my FIT off EDF and my electricity off Octopus. 

2. I have an EV and that could also benefit from the battery energy store. I've read that using a solar diverter on an EV is a no-no but the battery would I think change things by giving continuity of charge. In the summer I'd just set it to charge for an hour or two, say, for a bit of solar top-up at 2KW charge rate.

3. For anyone who has installed a similar system,  how is it performing?  What sort of installation costs? 

 

Thanks

We have FiT, storage battery, EV and solar diverter .....

Charge everything up at night !

Sunsynk 5kw inverter £900

2 x 14.3kw batteries @£2400 each (only one installed, the other is sat in boxes ready to assemble) 

Solar diverter £120 

We receive FiT payments around £900 per year from British Gas

Just moved onto Intelligent Octopus as we've just bought a PHEV, looking to reduce our bills as a result, so I need that second battery soon, but I've got a lot on as we've had to renovate one of our rentals! 

We are all electric including overnight storage heaters, which I changed to Dimplex Quantums a couple of years ago, hence the desire to reduce our electricity bill! 

@misterb Just the sort of setup I'm looking at! Can you say what you use the diverter for? 

And I've been looking at a Dimplex QM100RF but there's lack of technical information on it. I contacted Dimplex and they told me it could store 15.4KWh but only output at 1KW. Which doesn't stack up really. Do you have any better info on this?

Solar diverter is to send excess PV to the immersion heater. The CT clamp goes AFTER the CT clamp to the inverter, so excess PV first goes to the battery, when that is 'full', excess goes to the immersion heater, when that no longer requires heat the excess goes to the grid. I am on deemed export via FiT so try to use as much as possible. Of course while all this is going on I am still using the PV to power to whatever I'm using in the home ie lights, fridge freezers, TV etc 

I dint know the specifics re the Dimplex other than they charge up overnight and give out the heat throughout the day, as and when I set them to. They are a massive improvement on my old storage heate s and reduced my bills a lot BUT more importantly they give our heat when I need them to and have lots left in them come the cold nights.

I also run a diesel heater in the kitchen/dining room/conservatory during the winter as a boost to the fujitusu inverter (air to air heat pump) which I run in reverse in the summer to provide air con! 

'Ive also laid pipework for UF heating in the conservatory but to be honest, we do ok with what we have!! One day I will look at fitting a small heat pump or even a swimming pool heat pump as it's only a couple of rooms ...

Posted by: @geo3geo

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.

3. For anyone who has installed a similar system,  how is it performing?  What sort of installation costs?

Thanks for this post @geo3geo  and the really interesting thread that it has generated.

I have just had a 7KW Daikin Altherma ASHP fitted by Octopus on our 3 bed 1950s semi. This is added to a system with 5KW PV, 3.5KWh Pylontech Batteries and Solus inverter, solar water heating and a Hyundai Ioniq 5 with 58KWh battery capable of V2L upto 3.6KW. To boot a hot feed dishwasher and a paranoid off grid island mode switch for power cuts and living room wood stove for nesh winter nights :). 

Only on day 2 of having added the ASHP so looking at tips on optimisation. 

Currently the V2L just powers a few appliances (washing machine, tumble drier, fridge freezer) in the garage, where the HP, solar water and tank gubbins is located.

I am considering cutting into the cable to the HP and adding an optional plug and big switch so I have the option to power the HP off the car battery when it's parked on the drive, especially in the winter, to max out the 8p per unit night tariff :). If not that, then at least to provide for the 3KW immersion heater on the tank in the winter, when the HP is less efficient and the SWH and PV output is minimal, but we still need lots of HW for washing and dishwasher.

Thoughts?

J

@windymiller Does the V2L facility not allow you to connect into your domestic feed as for instance my Tesla Powerwall kit does? I can power the HP (which is connected to my domestic wiring at the consumer unit) as I can any other domestic load. I have 27 kW/h of battery and am on OE’s Agile Tariff; most of my charging up is done at night during greenest / cheapest power and this runs my system quite happily. I have a Daikin 8 kW monobloc which can draw a little over 2 kW/h in cold weather to heat our house to 22.5 degtess 24/7. I don’t have a car thus have no experience of EV kit. Regards, Toodles.

 Ah... that would be defined as V2H (Vehicle to Home) or V2G (Vehicle to Grid) @toodles

In either case you'd require G98 approval for the inverter, G99 for the site and LCT permission for a 'charging point'.
V2H would be required to have its export capability (of zero kWh) approved by the ENA.

One of the advantages of V2L (Vehicle to Load) is that it has no possible export.
Therefore it can be installed without your DNO being required to grant consent.

No doubt @windymiller can verify if I've provided adequate explanation of the differences.
As far as I can tell, V2L is a cousin of an off-grid inverter.
Both would have a 50Hz oscillator inbuilt, rather than being synchronised to the grid frequency.

 @toodles great to hear the powerwall enables V2H. It definitely makes sense to maximise the utility of the giant wheeled battery parked on the drive. Charging up the car at night to have the HP powered entirely at the 8p OE Intelligent tariff rate, when gas costs 7.5p per unit (before boiler efficiency losses) is a massive saving, with a COP north of 3.5 :).

@transparent, yep that's right. I find V2L is really simple.The Hyundai has an onboard off grid inverter making it into a massive mobile battery pack. The MG ZX has the same. Meaning you can just run an extension lead from the car to any plugin loads. There is even a 3 pin UK plug socket under the rear seats, though I have a cable plugged into the main charger port running into the garage.

As the car and loads are not connected to the grid there is no need for any conversation with or permissions from DNOs etc.

I actually have my whole house set up with a manual switch over to off grid battery if there is a power cut, though this just uses the domestic batteries at the mo. I don't have the HP wired into my paranoid island mode, as it would quickly drain the bats. Island mode just maintains the lights and plug sockets, so our kids can keep binging YouTube and doom scrolling while our neighbours light candles and rediscover the art of conversation 🙂

I haven't yet heard of anyone else doing a similar V2L ASHP integration, so was wondering if there were any possible risks that I might need to mitigate.