Dillsue

If you look at some of the Tesla app screen shots it details the power from SE as "solar" so its fair to assume that SE is wired into the Teslas solar input.

If the SE battery is DC coupled, the PW doesnt know if the SE inverter output is from PV or battery?? If SE sees the EV charging demand wont it start to power that load? Because PW assumes SE output is PV wont PW reduce output to let the SE "PV" fulfil the EV charging demand, so SE will discharge before PW???

Surely as they both see the grid demand intially rise then fall off as both batteries try to satisfy the demand, there wont be 2kw of surplus but both batteries could start to ocillate output?? If one battery is not quite as reactive to demand then the more reactive battery will supply all demand until its discharged??

As both batteries need to be configured to supply household load, which includes the other battery charging, are you saying run the AC connection cable for one battery through the other batteries CT?

Sparky is signing to say the installation is ok. Its up to him if hes happy to test/inspect someone elses work.

Not suggesting you use SE but just showing that you can have an array thats far bigger than the inverters rating. Check your preferred manufacturers spec to see if they are the same as it may save you changing your inverter?? We had an optimiser fail a few years ago and SE did remote diagnosis and sent a replacement straight away. I looked at the trust pilot reveiws and many are frustrations with installers and many are from the US posting on a UK web site. Not really a true reflection on SE, in my view and experience. Everyone gets shading as it includes segull s**t, saharan dust, algae, passing cloud shadows, snow, faulty module etc. With a conventionally wired system, the entire string output is reduced when any of the above happen to one or more panels. Youve also got individual panel monitoring with optimisers (or micro inverters) so you can see at a glance if youve got a problem. With conventionally wired panels it could take months or years to spot a problem, if ever!

Exact same time as our first system. It may have been a FIT banding limit that the installer worked to which is what limits ours to 4kwp of PV with a 4kw inverter that can take 5.4kwp of PV input.

If you are thinking storage for the entire winter then no it doesnt work like that unless you have container loads of batteries and a much larger array than 3.9kw to charge it through the summer. If you work out your approx daily usage in the winter then compare it to battery capacity youll likely see that a typical fully charged battery will only supply you for a day or 2 if youre frugal but much less with an ASHP. What a battery allows you to do is capture any excess from a sunny day and then use that excess to run the house in the evening/next morning before the sun is up again the next day. If the next day is dull youll be running on grid power pretty quickly depending on usage and battery capacity. To get significantly more self generation in the winter youll likely need an array significantly bigger than 3.9kw. If you google PVGIS theres a forecasting program that estimates by year/month/hour how much youll generate. Compare the forecast winter generation to your usage calcs and youll see what the shortfall is.

If you check your inverter specs, you could well be able to add those now👍

An SE5000H can have up to 7.750kw of DC input and an SE6000H can have up to 9.3kw so just shy of your total array. If the array is split over different orientations, so panels arent all generating at peak at the same time, then you can have more PV than the stated max input. I think yours was an installer limit, not an SE one as even a now obsolete SE4000-16 could have 5.4kw attached

Your sparkys details go in the installers section. You spark should know his credentials!!

I cant speak for other manufacturers but Solaredge allow significant oversizing of the array for a given size of inverter...an SE3680H is rated at the G98 limit of 3.68kw but can have up to 5.7kw of panels connected. Youll see some some clipping on clear sunny days for a few weeks of the summer but most of the year youll be able to use everything off the array. We installed an SE3680H with 5.1kw of panels at my daughters house earlier this year and her hubby was fretting about clipping when it was sunny but has got his head round the fact that its only gonna be short lived in the peak of the summer

Yep thats the same one

Solar energy store on ebay

As I understand it a 3 phase inverter will balance the power generated over the 3 phases so any single phase equipment, maybe your ASHP?, will only have access to a third of the generated power. If youre only likely to ever install 3.9kw of PV seems to me a single phase 16amp/G98 limited inverter would be the way forward and connect the inverter and house loads to one phase?? When planning your usage remember that your PV will likely be generating next to nothing in the winter when you need the ASHP the most!

That document you linked to is very interesting. If you look at the top of page 9 it refers to non accreditted extensions not affecting FIT payments from the original accreditted system. I read that as meaning you dont need an MCS installed extension to continue receiving FIT from the original accreditted installation, so DIY extensions are ok?? If you are limited on space for an extension that might not help you too much. Theres also a link at the bottom of the last page to a similar document covering battery storage install. I didnt read it in depth but it seems to be quite favourable towards batteries so your batteries could be ok. I seem to recall someone posted that they had added batteries to a FIT system, so likely its doable legitimately.

Probably best to ask an MCS installer if theyll sign off work youve done and kit that you may have supplied. 400watt panels are likely 1100mm+ wide versus under a metre for the 190s so assuming a 2x7 array youve got at least 700mm of extra rail width. The panel height will likely be 100mm different so you may need to move the top and bottom rails if youre unlucky. Maybe worth checking the panel mounting so your clear whats needed?? MCS guys are not known for lashing things up so you want to be clear that you can extend/relocate mounts

If youve already got G99 approval then that export capacity is in the bag for life, so no worries on the DNO front. MCS is a bit trickier. Someone posted recently that MCS arent the only accreditation scheme that qualify you for export payments?? I think that over time with a drive for greener generation you may find companies will be less picky as to which micro generators they buy from and it maybe that you pay a small inspection fee to check youve actually got PV/wind/water turbine and theyll buy your export?? Theres also at least one company advertising PV kits for self install that will do MCS commission and certification if you buy and install their kit. Way cheaper way of getting MCS accreditation.

TIC is total installed capacity, so that statement says that if you increase TIC you wont get paid for it. Lets say you doubled your capacity then youll only get paid for half what you subsequently generate, so you are still only getting paid for generation off the originally installed and registered TIC. Im fairly sure you need to have the extra capacity installed by an MCS installer so youll pay through the nose for the extension, yet get no premium return by way of extra FITs. Maybe Im reading what you are saying wrongly, but thats my understanding based on enquiries I made a few years back, post 2016 but before covid.

You need to speak to your FIT payment provider as OFGEM dont get involved with customers. I asked OFGEM a similar question a few years back and thats the response I got back. From what I understand you can only change things on a like for like basis if something has failed. Upgrading the size of the array is unlikely to fall into the definition of like for like. Only exception would be if a 190watt panel failed and a direct replacement wasnt available then I think youd be justified in going to the next larger available size, but thats unlikely to be 400 watt and it wouldnt be all the panels either. If you ask and get approval definitely post back as theres likely 1000's of peeps that would love to up their FIT payments, me included. Even if you could fo this swap one of the savings you mentioned was no change to the mounts but I think youll find 400 watt panels are considerably larger than your 190s

No!!! He fills in either a G98 OR G99, not both. If he keeps his export below 16amp/3.68kw and uses a G98 certified inverter, then he notifies UKPN that he has solar PV that has 16amp limited export. Its a G98 notification, not an application. The notification goes in after the system is connected to the grid If he wants to export more than 16amps because he has more to export OR he doesnt use a G98 certified inverter, then he has to ask permission via a G99 application. The G99 goes in before the system is connected to the grid and you need approval before you connect to the grid The spark signs off the install/test paperwork in either case. Unless theres extra complexitiy added to limit export via G100 theres not normally a DNO inspection, AFAIK G98 is straight forward and G99 can be if you keep things simple and sensible, in my experience.

If your mate wants to be grid tied then its no problem exporting if he keeps export under 16amp/3.68kw. Any export just goes into the grid for someone else to use. If you want paying for any export you need a professionally installed system almost certainly using new parts and costing ££££££ G98 is a notification not an application form, if your max export is 16amp or less. You notify with a G98 and apply for permission with a G99 application. Work out who your DNO is and Google G98+their name to get the form. A spark can sign off the install

You tell the DNO what you want to export to the grid, and what equipment your going to use to limit the export to what youre applying for, the DNO then says yeah or yeah but upgrades are required. Once youve got approval and done the work send the DNO the completed commissioning form and a simple drawing showing how things are connected. If youre mate keeps export under 16amp then he just notifies the DNO via a G98 notification. Getting paid for export is a differnt set of certification/approvals from getting permission to connect to the grid.

Set app is used with later HD wave inverters which would be an SE5000H. If yours was installed in 2015 it will be the older SE5000. If thats the case the wifi connection is set up from the inverters display and is covered in the manual.

If you can log onto the portal, but theres no updated monitoring data, then check the inverters internet connection. If youve changed router/ISP/wifi password then the inverter cant send monitoring data. If youve had a replacement inverter then the new inverters serial number needs adding to the monitoring portal. If its not the internet connection then probably need to log the fault with SE as they can do remote diagnostics