Dillsue

I think our low uplift for extensive PV may be down to the Assessor, but maybe a limitation of RDSAP not accepting the uncertified 8.5kw of self installed PV?? Another quirk was that the Assessor reckoned we may have scored slightly better with a modern gas boiler over the ASHP we have. His explanation for this was that as we are heating with radiators the system assumes a 55 degree flow temp which hits the HP efficiency. He reckoned there was no way to alter this to our actual flow temp of 30ish. I think the new HEM would likely give us a way better score than RDSAP but that will have to wait for another day

We've recently had our EPC redone and 12.5kw of panels added a few points but surprised me how little it added. We've got a 4kw MCS system and 8.5kw self installed and the Assessor seemed to struggle with getting those entered into the system. He ended up putting the panels in by area as a percentage of roof area covered. I got the impression that assessor wasn't too familiar with anything non standard so maybe there are alternative ways that may get a better score??

When taling about ROI, you mention 5kw(kwh) of batteries in several posts so I assumed you're planning on getting some

16kwh Fogstar batteries are £1850, I paid £700 earlier this year for a 5kw solis hybrid inverter, a grand for panel mounts, £500 for inverter connection/sundries. Your return is looking much better and you've got treble the battery capacity to play with.

One advantage for the DNOs if inverters are regulated by power rather than current is that if they wind the voltage up everyone's inverters throttle the current so easier on the grid. Our original solaredge SE4000-16, limited the current rather than power and with our base voltage being 25x vac I've seen up to 4.2kw going to export. When that died the warranty replacement was a newer HD Wave version that limits by power so sadly always capped at 3.68kw

16A is without consent via G98. We have 32A via a G99 but I think others have posted higher limits.

Are you talking about volume/quantity(kwh) or the rate(kw) of export?? I don't think anyone in a domestic situation gets limited on the volume they can export but everyone gets limited on the rate they can export as ultimately you'll blow your service fuse if you try and push power into the grid too fast! Most are limited way below the power that would blow their fuse though!

Adding a battery potentially changes the dynamics. In the winter panels spread through 180 degrees from E-W will likely generate less than the same panels all facing south and pumping the peak generation into a battery. Run the figures through PVGIS and see how it pans out ie 2kw East + 2kw West versus 4 kw facing south

Whatever export limit the DNO sets you can always have a much bigger inverter and array and just export limit via G99+G100.

The battery wouldn't care if the inverter is 5 or 100m away but your wallet would when you buy the connecting cable. Our battery comes with 50mm2 cables for a 1.5m run

When we added a second set of PV a few years ago the plan was to have generation all day long by spreading the panels from SE to NW as we didn't have a battery. The NW array does virtually nothing in the winter but does keep the generation going to cook tea for maybe 6 months of the year. Now we have a battery charged off cheap overnight eleccy we let all the PV run to the grid and grab the Octopus export payments. Without a battery you'd need quite a sizeable array correctly orientated to power you through early morning and evening without drawing much from the grid, even in summer. PVGIS gives your hourly generation forecasts so you can have a play and model the panels you could install versus the house load through the day. Or get a battery.

Not sure if all inverters have them but I'm pretty sure Solaredge inverters have a built in RCD so even with a faulty grid loss shutdown the in built RCD should take care of anyone zapping themselves.

If it's an armoured cable and you have a route along a fence, why not clip it to the fence rails or tywrap it to a strand of fencing wire.

The 2 arrays don't have to be operating near maximum. With the figures I posted one array can be near max and the other at 50% for the inverter to start clipping output. I dont know the difference in price between a single and dual MPPT inverter but would guess its not much. Going for a dual input removes this issue entirely and would then avoid clipping for the life of the system

If your getting around 4p/unit with octopus it's SEG. If your talking about the 12p/unit deal that's a power purchase agreement. The former is gov regulated but the latter is an unregulated contract between you and whoever wants to buy your export.