Dillsue

Run a beefy SWA as suggested and a run of blue alkethene water pipe with a draw wire in it and you can pull in whatever data cable you/your installer wants.

The 4000tl spec Ive just looked at has max DC input as 4.2kw so quite limited. It also seems to have 2 MPPT inputs so if only one is currently wired you could hang your new panels on the free input. PVGIS will give you hourly data which you can crunch in Excel. Put in all the panels facing the same direction AND inclination as a single array and down load the data for the best FIT generation year youve had. Repeat for the remaining panels grouping them in separate arrays by common direction and inclination. Once you've downloaded all the data put the date, time and kw from each dataset into a new sheet. Add all the kw values to give you total kw for every time period. Then sort the entire sheet by kw total column to see what your likely peak kw DC input is. If its 4.2kw or less then youre good to go, otherwise a bit more thinking. Bear in mind that if your max PVGIS input is close to the inverter limit, then over time you might have problems with changing weather. Despite the fact that panel output is supposed to drop off over time, we've just had our best annual generation since 2015 on our FIT system.... climate change or a one off???

Have a look at the spec for your existing inverter as you may well be able to have way more DC input from panels than the inverter rating. Our older 4kw inverter can accept 5.4kw of panels and our newer 3.68kw inverter can accept 5.7kw of panels. Extending the system rather than adding a second system keeps you within the OFGEM guidance for pro rata payments and no worries about export limitation. If you put a second system in with DIY export limitation, you probably dont want to declare that to Octopus as Id be surprised if they'd accept a casual limitation set up that you could easily remove or alter yourself........unless anyone has done this????

Not sure of your figures but if youve got a PV diverter wouldnt you be better off on deemed export??

The DNO has said the extra panels will be ok so no need to limit export

You were talking about a micro inverter solution so I assume that's what youve already got?? Solaredge optimisers deal with a mix of panel sizes and I assume micro inverters do too but that would be a question for the manufacturers tech support. It's the micro inverters that interact with each other, not the panels, so you can probably use whatever panels you want up to the limits of the micro inverters they are connected to. Plugging in 4 additional micro inverters into an existing loop shouldnt be a problem and if you use factory assembled and tested inverters/cables/plugs then its straight forward to connect up.

The FIT rules have changed and you can alter a FIT system without losing your payments- https://www.google.com/url?sa=t&source=web&rct=j&url=https://www.ofgem.gov.uk/sites/default/files/2021-12/Feed-in%20Tariffs_Guidance%20for%20renewable%20installations_V16.pdf&ved=2ahUKEwi91OP77aT8AhVHTUEAHebpBEoQFnoECBIQAQ&usg=AOvVaw3i84Pu-SO0Ibm-lhEjzfaT

No experience with Solis kit but an RS485 connection could well be a local network for connection to an energy meter, battery pack or another inverter. If your expecting to see a value for grid export then have you got or going to have an export meter? If thats yet to be installed/cabled, that could be why you got red lights/errors and your installer idnt too concerned??

If you are having for about to have the house wired, is that utilising the 3 phase? If not, I'd speak to your sparks and tell them you may be going for 3 phase and could they consider that in any work they are doing now. If you go for a 15kw system, WP could well ask you to spread it over the 3 phases so you would need the house wiring over 3 phases to use your PV. That said there was a post on here a while ago saying if you have a smart meter with net metering any unused exported PV on one or two phases will cancel out an equivalent amount of imported energy on the third phase. You look to be calculating the forecast monthly PV generation with a panel "efficiency" figure. You'll likely get more accurate figures if you Google PVGIS, input your data and use their forecast figures. If you are focussed on ROI, you might want to run your calculations using a variety of grid kwh unit figures. I cant see the current unit rates lasting too long!

Tradesparky/solarsparky always seem competively priced but Google the panels you want and see what comes up. Bear in mind that for panels, there can be significant delivery charges so somewhere near to you may work out competitive if you can collect.

Google PVGIS and put your details in to see what output youll get

No provocation intended, but if it did then guilty as charged

I think the UK intent would include CCS too. As for viability, we might know in the next 5 or so years- https://www.essar.com/essar-oil-uk-to-build-360-million-carbon-capture-facility-to-deliver-on-its-ambition-is-to-be-a-leading-low-carbon-refinery/

Then read the BEIS forecast doc I pointed you to if you want a finger in the air guesstimate. This is hard work!

I'm trying to help you find the info you want. You asked what percentage peak providers needed to cover. If the wind isnt blowing on a cold winter evening then alternatives need provide not far off 100%. If you look at gridwatch, CCGT alone was doing up to 65% around 12 Dec. If you want to know generation breakdown in 2050 you should have said that. Google BEIS energy predictions and youll find forecasts through to 2050 by generation type. Unfortunately for you, FF use is predicted to be 19% in 2040 and 14% in 2050, from memory!!

If you go to Gridwatch and scroll down the home page, theres a list of UK generators that includes fuel type and capacity so if you get your calculator out you can add up whatever figures you want to understand. If youre clever you may be able to paste it into Excel to play around with??

We heat by logs and many years ago a friend was helping splitting and stacking and remarked how cheap our energy(gas and electric) was compared to the work involved in processing logs. Energy has been cheap. We need to pay what it costs if we want the luxury of reliable, on demand and limitless energy.

You don't need a genny that big to keep the basics running. We have a 1.5kva unit. It does require fuel but we have that already for the mower. If the genny is stored indoors it'll only need servicing every few years but give it an hour's loaded use at the beginning of winter and buy a Honda powered unit. We dont hear ours in the house when its running. An EPS relies on a charged battery which in the winter will primarily be off the grid as youll not get much out of a 4kw array. If youre planning on off peak charging make sure you keep enough in the battery at the end of the day to keep you powered through an evening blackout. I'm a bit biased towards genny back up as we had the power off for 3 days over Xmas in the 90s and have never been without a genny since

Same way as we finance lots of idle gas power stations now??

You might want to look into a small generator if your concerned about blackouts. Not seamless backup but will run for days if needed and way less than the cost of an EPS unit. A small genny is unlikely to power an ASHP, cooker or shower but it will keep the lights, telly, internet, microwave and CH running.

We've got 2 Owl CTs inside our main CU, although not on the incoming tails. Probably doable to get one on the main supply but the Owl CTs are quite compact

I think gov figures for the whole of 2021 were 38% renewable generation from all renewables. Still along way to go

https://www.orbitalmarine.com/ Up and running https://www.morlaisenergy.com/ Work in progress https://simecatlantis.com/tidal-stream/meygen/ Up and running I know about these but Im sure theres others around

Youve got a few options. First and obvious one is speak to your DNO as they can be surprisingly helpful and may have capacity to take your full potential output. 2- agree a lower export limit with your DNO and implement an export limitation system. Fair chance your DNO will want to witness a limitation system operating so in addition to extra equipment there could be a charge for a witness test. 3- go partly off grid as already suggested. Likely a few bits of extra kit to be housed indoors and a second consumer unit with some circuits being moved to the new CU. 4- get an integrated battery system that manages PV generation and limits export from both PV and/or battery. I've no experience with batteries but I beleive the latest Tesla powerwall have an integrated PV inverter and if you get the G98/3.68kw limited version you don't need DNO approval to connect, just notify them once its installed. Victron do a big range of battery/PV management kit so they may do something similar??? 5- put in a DC coupled battery system where the inverter limits output. Similar to 4 but separate units so doesn't have to be a big cash outlay all at once. Solaredge do an energy bank and I think others do similar modular DC coupled systems. Speaking to your DNO first seems the obvious way to go so you know what constraints youre up against

I wouldnt beat yourself up with a 'poor planning' title! In the thick of a whole house refurb youve managed to get one of your bigger PV problems sorted by running a cable through the house. With a circa 1 metre parapet wall youll likely be able to mount the inverter on the inside of the parapet if you needed to, but..... think hard about maintenance access on a 4 storey house before committing to putting the inverter on the roof. If you do go for a roof mount get a louvred canopy to go over the inverter to keep the worse of the weather off it