A typical domestic (single-phase) heat pump can take 30-35A when starting, which drops down to less than 10A once the compressor has got the fluids up to working pressure.
Plus there's a spike as the compressor motor starts which lasts around 1/10th second whilst the magnetic flux builds up.

So any inverter with a HP as a load must be able to deliver that output surge current whilst keeping the voltage within the required envelope.

What's the maximum continuous current and the surge current capability of the inverter within your Hyundai?

If you're 'running an extension lead', what's its current rating or conductor specification?

@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.

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.

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

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 ...

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?

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! 

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.