Dillsue

Did you tell them that you would set the SE to zero export to keep total export under the limit you already have? I understand that Tesla specs include multiple Powerwalls for the UK market so there's some disparity between what your DNO seems to be saying and what Tesla are saying.

There's no difference between a 3.68kw Powerwall exporting and a 3.68kw SE inverter exporting. If you disable the SE inverters export and replace it with a second Powerwall theres no difference to the grid as its still 8.7kw total. When you asked your DNO about adding a second Powerwall(3.68kw)did you tell them you are disabling the SE inverters export?? If it's more storage youre after then go for the extra SE battery. If you want more power to the house then adding an SE battery wont make any difference as your SE is limited to 3.68kw

You've already got consent for 8.7kw export so configure your SE inverter to zero export, existing Powerwall to 5kw and new Powerwall to 3.68kw. Max export will be what it is now and youll have 5+3.68+3.68kw to use in the house. You'll likely need to do a G99+G100 application. I think youve already got a SE energy meter so SE configuration will just need the export limit setting, but check your inverter has a G100 certificate Simples

PW spec says 5kw sustained 7kw short bursts so may be worth checking they dont mean collective export is 8.6kw when SE is at max?? There wasnt a note at the bottom saying you got what you want but warranty is now void

But the vast majority of EV charging will be from the grid. I assume/hope that any PV input into the charger will be downstream of the meter??

Inverter sorts that out. AFAIK theres a comms link between the inverter and the batteries with each battery pack having a charge controller. Black magic takes place and you're batteries get charged. If its an SE3680H inverter youve got even with 30kwh storage youll still be limited to 3.6kw from the inverter

And........ I beleive the next generation of EV chargers is mandated to have smart meters built in. I suspect as a minimum the correct rate of VAT can then be charged?? Could also be used for remote disconnection at peak times??

You can have 3 SE batteries according to this https://www.solaredge.com/en/products/residential/storage-and-backup/solaredge-home-battery-400v

Solaredge allow significantly more oversizing than 20% with a 3.6kw SE3680H accepting up to 5.7kw DC input which is 55% oversizing. Split the panels over differing compass points and you can have much more.

I think theres a few that do bespoke cylinders and you can have more or less what you want where you want so coils/tappings/connections can be put where you need them for the space/piping/accessibility youve got. Have a good think what you need, tell them and they'll lead you on the design. We used a copper cylinder manufacturer in Newark who were good.

AFAIK PW2 can be set to 0kw, 3.68kw(for G98 compliance) or 5kw export. Your SE3680 is limited to 3.68kw as it is without any other export limitation. If youre only see max 3.68kw from your PW then that seems set wrong. Maybe needs upping to 5kw if youve got DNO approval for that. Not sure that photo of your schematic from your other thread is correct as the Gateway doesnt seem in the right place??

Murdering the economics.

We don't have batteries. Just because you can't get export payments doesn't automatically mean youll get batteries.

What are you basing that on? Our systems are doing just fine

That's correct, IF you choose to get export payments. If you dont want export payments then no MCS needed for PV install.

Thats wrong. You cant power up or connect to the grid til your spark has tested and certified the cabling. Absolutely no mandatory MCS involvement

For heat pump install, MCS doesnt have a secure grip. It's a few hundred quid for a planning application out of a suggested £5k install cost. No MCS involvement. Just your friendly spark thats testing your PV cables

?? Anyone can install PV. You just need a spark to test site installed cabling

The table near the beginning of that linked doc says increased capacity upgrades are free. Guess there may be a bit of a wait but should be able to export what you want, in time. Took our DNO best part of a year to upgrade our transformer, but they did make a bit of a meal of it with new poles/cables etc.

We added a second 3.68kw PV system last year to give 7.4kw max export and our DNO didnt charge for a transformer upgrade. I suspect it was because the original transformer was undersized by today's standards, but they could have asked for something towards it??? @pocsterId have thought youd be able to get more than the 3.68kw G98 limit fairly easy?? You in the middle of nowhere fed by a bit 2.5 twin and earth?

Fairly likely that cooling demand will coincide with PV generation, but nationally, we've a pittance of PV generation so any cooling demand is gonna ramp up gas generation. Obviously theres a few people with their own rooftop PV that may be able to power their own cooling during the day and into the evening if they've got batteries, but without personal PV and batteries, any cooling demand will be gas powered. The thread is looking at ways to accelerate ASHP roll out including a big cut in cost. Adding PV to every ASHP capable of cooling to make the cooling grid independant is gonna put the cost way up so its probably best that ASHP with cooling remains outside PD.

But those without cooling will likely have their windows open all the time and may not appreciate their neighbours AC/ASHP running 24/7. The other thing to remember about the luxury of cooling is that its almost certainly gas generation powered so just adding to our collective emmissions

No confusion caused. My post wasnt a particular dig at what you said but more a general comment that most of the population dont see their emmissions as part of the problem. Therefore theyre doing didly about them.

I think this view is the crux of the problem that we face as most people dont think they are the cause of the climate change problem, as they're only a tiny proportion of the emmissions in the world. First thing we need to address is that we're all responsible and no body is exempt

Your inverter size will depend on the max output from your split array which you should have from crunching PVGIS data mentioned earlier. What's the max DC generation? With a split 8/9kw array youll likely be looking at over 3.68kw AC output so a G99 application will be needed. If thats the case, then speak to your DNO to see what the max export theyll allow you. When you speak to them, don't quote the array size but use the calculated DC generation figure!! When you choose your inverter check its on the ENA type test database. If your DNO wants export limitation make sure the inverter has a G100 certificate