Dillsue

Its unlikely a 6kw inverter will be manufacturer limited to 16 amps so youll need to submit a G99 application and get approval before connection to the grid.

Exactly this. "Pay back" depends on motivation for doing something, installing PV in this case. If youre doing it for green reasons then ROI may not be relevant with the reverse also being true. If you want autonomy from the grid then ROI might not matter much if atall. How you use and maintain a PV system can have a big effect on ROI if thats what your focus is, less of an effect on the environment if thats your focus

Maybe Im mistaken but as understand it one of the ways to make the most of the agile tarriff is to charge batteries from PV during the day or from cheap rate eleccy overnight, then discharge to the grid in the evening peak to grab the highest export rates??

I think the backup unit is an integrated inverter/charger and grid disconnect unit all in one, so there isnt a "main" inverter. Im guessing the inverter is able to run in off grid/island mode only when the disconnect device(contactor?) has isolated the house from the grid. Not sure if theyve got certification in the UK yet??

For the max voltage have a look at the label on the panel or the data sheet. Ive just looked at one Ive installed recently and its 1500 volts. Youre unlikely to have problems with the voltage applied by a series of upstream panels and the max panel voltage could well be higher than the input to your inverter?? By series wiring differing panels youll limit the string current to that of the lowest current panel, so if you put a 250w in series with a 310w that strings current will be limited to 8.11A even though the 310w could push 8.52 By wiring in parallel each panel drives whatever current it can but higher voltage panels have their voltage pulled down to that of the lowest voltage panel. Not sure what system youre installing but micro inverters or optimsers do away with this problem and allow mixed size panels. On the optimised solaredge system weve just put in weve got 405w and 335w on one string and 310w and 320w on the second string. The optimisers deal with all the current/voltage regulation and the panels just feed the optimisers with whatever they are rated at. Makes later extensions a piece of cake👍

You can check the inverter is listed on the ENA database, as above. If its on the database its hard to see how your DNO could refuse to accept your inverter. For your budget dont forget youll be charged VAT and/or import duty when the goods arrive in the UK.

Theres a guy on ebay selling kits that is based in southampton. Search for "solar panel" then order the results by nearest first. He doesnt always include mounts so make sure you allow for these.

AFAIK your options are micro inverters, Tigo optimisers or SolarEdge optimisers. There maybe other individual panel power processing systems but those seem to be the common ones. All will help with shading but wont elimnate the problem. If your array is shaded til 14.30 your not going to get much generation in the winter. Is it possible to prune the trees a little or relocate the panels?

What was the driver to go for micro inverters originally?

As I understand things, the PV industry is running flat out and seemingly install prices have gone up noticeably this spring/summer. I know personally theres been material shortages. If you get a quote now youll likely be asked to pay more than you would have 6 months ago so it might be worth putting things on ice for a few months hoping that things calm down in the autumn/winter?? That said the October price cap hike might fire up the industry further????

Technically you cant 100% do a DIY install as you need a qualified spark to test and certify the install. You can do all the work but you need a spark to test before you connect up to the mains. That said, theres lots that dont do that.

Unless youve specifically installed a system to monitor export and throttle generation if you start exporting, any excess just goes to the grid. Unless youve got a DNO restriction on what you can export, I cant see a reason why you would not want to let excess go to the grid.

If you want to connect to the UK grid, Im pretty sure the kit you use has to have a manufscturers cert on the ENA type approved database. CE/UKCAS/MCS has nothing to do with the ENA type approval. Best thing for you to do is work out who your DNO is then ask them. Id be comfortable betting my kids that on the G98 notification or the G99 application form that the principle thing they want to know about is the ENA type approval cert.

I dont think thats correct!! To connect to the grid your inverter needs to be ENA G98/G99 compliant, no MCS required. MCS is an optional quality certification that allows you to get paid for export generation. We had G99 approval to connect a second G98 inverter and theres no MCS involved.

I think its typically twice that at £6k for a 4kwp

If it was wired in twin and earth or SWA youd have the same problem of separating the live conductor to get a CT round it. Equally problematic with twin and earth/SWA/flex/YY. Theres usually enough space inside a consumer unit to get a CT on the PV live wire, certainly with Owl CTs

YY = flex which is used for power and control. The Eland cables link raises specific concerns about the metallic braid on CY and SY but nothing specific about YY. Heres a link to Lapps YY offering which specifically states used for power https://lapplimited.lappgroup.com/products/yy-cable.html YY/flex is unarmoured double insulated which is exactly the same protection as twin and earth. I think its fair to assume the spark that did the OPs install is comfortable using YY/flex and as its a new build will have almost certainly been signed off by a qualified spark.........you would assume!!

Yes. Have a look on the ENA inverter database for any make/model youre thinking of buying to verify the G98 cert. If a manufacturer has bothered to type test and certify their inverter, Id be fairly comfortable buying their kit

CE marking is potentially meaningless for a personal import from outside the EU. If something dodgy injures you who you gonna complain to...... a company in China whos name you cant pronounce. As mentioned a few years ago rumour has it chinese companies were using a very similar CE mark that they said was a "China Export" mark and noghing to do with European CE marking

Whys that? You can get "flex"/YY cable in a big range of sizes capable of handling much more than 2.5kw.

If its a new build it shouldnt be too hard to track down the spark that installed the system via the site agent/builder. Failing that if youve not been given an in home display for your smart meter youll likely be able to get one from your eleccy supplier or off ebay. If you want to see what youre generating without going in the loft, you can get simple wireless energy meters that fit round the live conductor of the cable from your inverter and transmit to a small display- have a look at Owl Micro as an example. Youll likely need to get a spark to fit the clamp that measures the current depending on your competancy

Spot on. If DC connected, the inverter does the overall limiting whether its from PV, batteries or both. Technically you should tell the DNO about the change of inverter and if the new and old have the same limited output and have a manufacturers cert on the ENA database there'd be no issue

If the batteries are AC coupled then they have the potential to feed into the grid in addition to the 6kw PV you have approval to export. If your batteries can push out 5kw and your PV push out 6kw then your DNO will want to assess you potential export as 11kw.

Ah, could be that variant of HD wave

Each to their own! Thanks for the detailed explanation of your setup. Being non techy Id be sticking to standard SE kit. Your SE8000H inverter does all the battery charge management without a StorEdge interface?? SE do an xxxx- S4 variant of the StorEdge interface which is intended to be used with the HD wave inverters and I cant work out why that is needed as your HD wave inverter is managing the battery on its own. Anyone know why??