Dillsue

Have a read of this as pocster seems to be able to configure SE charging quite easily- All is not well in the PW SE multi verse https://forum.buildhub.org.uk/topic/28269-all-is-not-well-in-the-pw-se-multi-verse/

Renusol spec 5 mm minimum from top of tile to underside of bracket. If your brackets are the same ebay ones Ive tried, and they look the same, they flex more than the renusol ones so 5 mm is an absolute minimum. Its a tough call on how much clearance to have as the brackets push up the tile that sits on them so you have a big gap under the tile or have a big slot to cut in the tile so it sits back in place and doesn't lift the tiles around it

Feeding power back into the grid is called exporting which you may or maynot get paid for- google smart export guarantee(SEG). Grid tie is whether your inverter is connected to the grid or not(off grid). If the inverter is feeding the house and the house is connected to the grid, then youve got a grid tied inverter. Your heat pump is only going to pull 10kw for a few seconds during startup and a fraction of that once its running. Unless you cook on full power, your cooker could well run lower than the 4kw you mention. If you design your PV/battery system to supply all the peak house load you could end up with a overly large and very expensive system that rarely gets used. Youd likely be better letting the grid supply the short term peaks like the heat pump startup. I think alot of EV chargers let you schedule charging time so you could charge the EV away from meal times so youve not got cooking and charging load at the same time.

Your 5.7 kw of panels will only generate at that level for that small proportion of the year and anything generated over what the inverter can output doesnt get processed and is "wasted", during that shortish period of the year and for a few hours each day during peak generation. Early and late on peak summer days your oversized array will generate earlier and later in the day giving a longer spread of useful power but the generation peak will be "wasted" PVGIS gives hourly predictions so you can input your details and see how much any particular size of array will generate. I think you may need Excel to make sense of the data!!

I dont know about other manufacturers, but SE allow several kw of DC input over the inverters rating. A G98 SE3680H is rated at 3.68kw but can have up to 5.7kw panel input connected. If the array is split and facing differing directions you can have more connected so long as total generation at any one time is less than 5.7kw.

Putting Tigo optimisers or any individual module electronics on the roof gives just the same problem as SE optimisers if you get a failure. SE optimisers need to be connected to an SE inverter to get the safe 1 volt output feature to work, but SE produce a tool that allows the safe 1 volt feature to be disabled and I beleive their optimisers can then work with any inverter. Youll loose the monitoring but the optimisation will still work. As with everything in life if you want something that performs better then theres a price to pay which is the case with SE, but thats far from being had over a barrel. If you want the individual module monitoring and a better performing system then youve initially got to put your hand deeper in your pocket than you would with a simpler system, but thats an individual choice rather than a blanket "dont touch them"

Weve recently installed 2 x SE systems on top of the 2015 FIT system we already had. A breeze to install and very easy to add/alter if you want to expand/rearrange panels. We had an optimiser fail on the FIT system a few years ago which was easily spotted with SE module level monitoring. SE diagnosed the fault remotely and sent out a replacement within a few days... I didnt have to ask. Fitting the module is DIY if youve got access to an alloy scaffold tower(own/hire/borrow) OR a ladder and rope/harness. Remember that with an SE system youre only dealing with <40 volts on the roof. Loads of advantages with an SE system that have been detailed in previous posts👍

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