S2D2

Yes, this is already playing out with DNOs that will not fit larger than 80A cutouts. Plenty in my opinion but it makes the local charger installers panic when you have a 32A induction hob, 2x16A ovens and a 40A heat pump. I actually had to inform the latest I had round that the premium chargers do offer a second CT clamp to limit overall household power draw and avoid blowing the cutout. Their initial solution was just to hamstring the charger to not far off a granny charger at all times despite the fact the house load never goes above ~40A.

I agree with the Cosy point, it's very difficult to justify trebling battery size when you can just use Cosy with +50% on the cheap unit rate compared to the likes of Go.

I did a bit of digging and Octopus were asking for 5kW minimum g99 for power pack. Given lots of potential adopters will have g98 already, I don't see the DNOs approving a glut of 9kW+ export limits when this is more widespread. Tricky to see how that will come out the wash other than DNOs dynamically setting export limits e.g. via Octopus kraken. So more likely V2G will only be available if handing over control to your energy provider, or V2H with g100 without the grid balancing incentives.

Yes they had a reduced price on until recently, I thought they'd swap it out for the Glo but it's just disappeared entirely. Zero export removes the opportunity to balance the grid however, so I don't see that going through. It still requires G100 at the moment. Power pack needs a G99 certificate, so DNO permission is covered that way.

I did notice octopus are no longer installing Zappis, I can't find any additional information on what their charge charger (stupid name) supports but given they went with Zaptec for power pack I'd be surprised if it was bidirectional. More info next month probably. I imagine part of the UK issue is DNO permission, I assume they'll update the definition of generator to include bidirectional chargers. I'm assuming that technically at the moment the inverter in the car would need permission, but that makes no sense when your guest plugs in their car, or you plug it in at a different house.

I've just put this in myself, have a quick look at amazon best sellers and plan around the biggest backplate, I fitted this one because I didn't trust the small wallplate of your second option on dot and dab walls: Double socket and single gang brush plate with chunky conduit behind the wall. I took the view that AV cabling/terminations could change often so being able to pull the TV away from the wall and run a new cable through the conduit in seconds appealed without the faff of taking down the entire tv as per the first bracket. It does sit maybe 3cm further away from the wall than the fixed bracket, but that saved the need to buy 90 degree cabling as on my tv the only arc hdmi port is on the back of the TV. Some Amazon brackets sit much further away from the wall so some care needed when choosing one.

Octopus mini is your best bet (free) but I've been on the waiting list for years. Several DCC registered companies can access your DCC data if you give them permission, the one I've used previously is https://glowmarkt.com/bright. Data is a few days to a week behind depending on connectivity. They do an in home display that can get real time data and push it over MQTT, but it is not cheap and export has never worked for me. Octopus bills are never more than a few kWh out for me when compared to local logging, so I assume my smart meter connection is decent.

If you're not getting paid for export you'll probably have to reign back charges heavily at this time of year (depending on generation and usage of course). I only use the Cosy three charges during the winter, perhaps try just a single overnight charge? I use three different prediction APIs and take the mean, it still needs a healthy buffer for day to day variance and forecasts change throughout the day. So it can't really be relied on without some ability to course correct, like forced export or spare battery capacity.

Can you move your "several servers" to offsite hosting? These are likely the culprit and if they're doing serious work a minisplit starts to become inevitable.

A up - you stopped the job to take a picture of the imperfect edge. Turns out that's a shadow. B up - they seem to be stacked B up and who has the time to be flipping slabs over. But there appears to be some sort of seam I don't understand the purpose of - a way to get a clean break? Disclaimer: Never laid a slab in my life (may do soon) and stopped myself Googling it. For serious answers look elsewhere.

Which brand do you recommend for this and do they have a flow rate calculator to check if multiple oval runs are required? I'm about to install my system but running into issues with the drop to downstairs, the easiest route is down a partition wall with a rather inconvenient 72mm gap...

Next Drive was available for a short time for battery owners but the latest version reintroduced the requirement for an ev, no idea why. Octopus never asked for proof for Go but if they wanted to find users without, it wouldn't be too difficult from usage. Cosy is convenient and allows my small battery to cover heavy heat pump usage in the winter. I experimented with tweaking the heat pump but with just radiators decided it wasn't worth it and just the battery do the work, charging 3x per day. The only compromise is the higher cheap rate.

Eon next drive is good but I've stuck with Octopus Go because I use Cosy in the winter and can't be bothered switching supplier twice a year. I see Eon now have "Next Pumped" but that's only 8 hours cheap overnight (maybe, they dont show actual pricing online) so not a replacement for cosy with the 3 cheap periods. If your battery can get you through the rest of the day though, 6.7p on next drive is very attractive.

To be clear, I'm talking about bidirectional AC, where the pricey DC to AC inverter is in the car. The Zaptec Pro can be had for £800, a bit pricier than alternatives but cheaper than the AC to DC chargers like the Quasar. There's also no requirement to support islanding on cheaper models, it can just shut off if it loses grid connection like a standard inverter, islanding should be a premium add on and won't be supported on the octopus deal. I agree it has some way to go, but if every car supported bidirectional AC by default the decision would be much easier. My EV doesn't so I invested in an extra battery module for my hybrid inverter as it just makes more sense at the moment. I still use a granny charger as I dont want to invest in technology that's likely to become out of date immediately this year when bidirectional charging is readily available.

Seems like specific but inexpensive hardware is required so they were planning ahead with the Pro. MyEnergi also claim to be launching a bidirectional charger this year: https://support.myenergi.com/hc/en-gb/articles/15196766224273-Can-zappi-do-vehicle-to-grid-V2G

The Octopus deal is for a Zaptec Pro isn't it?

It sounded like Zaptec enabled V2G via a firmware update, is there specific hardware required for bidirectional AC or is it just some comms that other charger companies could add with a firmware update? The price of the charger indicates nothing fancy?

For the octopus deal its the car doing V2G afaik, nothing special about the charger. Octopus also control it, which is fair enough as the savings are passed on in the lease cost, but unsure if it would cover house load by design.

Thanks for clarifying, I had in my head that locked air could be an issue with the high pressure outlet, not sure why.

Can the straight nozzle on the upstand you mentioned in the linked thread cause issues with the trap as it seems to be eliminating that source of air intake or is there a distance to the T where that's no longer a consideration? Or do the bottle traps have their own? I fitted an anti-syphon u bend to and existing combination trap and it eliminated most, but not all, of the noise. I think even that was a recommendation of yours so thanks for the ongoing input!

Yes, but if you get a good surveyor they will let you oversize the rads to cover 150% of the heat loss (at design temp 50). Combine that with the fact they have to use MCS air changes rates and you can drop the flow temp from their design. Mine came out of heat punk at 42 based on their "design at 50".

I self installed an A2A unit a few years ago then had Octopus install a Daikin A2W in January. You could still choose at that point, check at the survey stage. Not that they should in a 4 year old house but dont let them install the 9-14kW version. 4-8kW are all the same just limited by software. It's personal preference but I vastly prefer A2W now I've had both, it also covers your hot water.

Mine was £2.2k after BUS from Octopus, 8 rads. About 8 man days of labour. Get some more quotes, many companies are openly overcharging because some people will pay it.

From memory not locally at the unit itself, but it integrates with the Tuya Smart platform which allows you to do remote control and off/on and mode of operation on an arbitrary weekly schedule. Oddly temperature is missing but it's possible I haven't added the correct integration. I was controlling it using a raspberry pi and the Python Tuya API, this is quite involved though as you have to get a local access key from the developer portal. This gave full control so allowed temperature and fan speed scheduling etc.

Most employees would be extremely happy with an 8.5% tax rate.