The Solar Thread

3.6kwh allowed.

there are fast track approvals though under certain circumstances .

Whos checking and whos knowing ?

Got you, thanks.  Filing under “looks too good to be true so…”.  I’m keen not to put the contractor in a compromised position so will have a bit of patience

It depends on the DNO – SSE wouldn’t allow our software constrained export (G98) and even after G99 approval, wouldn’t approve the system for export until it was checked over by their own people.

@Daffy.  OK, that’s good to know as I definitely am not tempted now!

It depends on the DNO – SSE wouldn’t allow our software constrained export (G98) and even after G99 approval, wouldn’t approve the system for export until it was checked over by their own people.

Whereas NPg were quite happy with my 7.3kW plus Powerwall system without any checking or witnessing.

Because I’m a senior manager at NPg (Head of Innovation when I applied, Head of Connections Design now) I kept my name out of the application as much as I could.

I had the installer apply and it went through very easily.
I did have to encourage them to give me the connection agreement for the export which my supplier wanted before they’d give me an export tariff.
Our process is being changed to make it easier (automatic hopefully) for the average customer who can’t just ring the MPAS Registration Manager direct.
Hopefully some of you will benefit from my problemette.
(We do learn and improve)

PS – I have had potential installers walk away from putting PV on my house when they found out I wanted it done properly and I knew what properly meant.

Why is the limit so low? I mean you can pull way more than 3.6 in and I’d assume the kit upstream is designed to handle high loads from a significant number of the end users connections.

It probably phase balancing

Apparently Musk / Tesla will be entering the UK energy supply business with Octopus style tariffs…

https://www.theguardian.com/technology/2023/jul/12/elon-musk-tesla-electric-supplier-britain

Wonder if Tesla will mind the Universal Supply Obligation, means they have to offer a Price Cap tariff to all including Prepayment customers..  I guess they want to ring-fence this to powerwall customers only?

Meanwhile: I have saved £660 in 6 months with my set up: 4.75kWp, 7,1kWh storage, MyEnergy Zappi, IPACE.  Done 10k miles, total cost of elec: £199 home, £151 public charging

@djglover – what is the payback time like on a system like that if you are saving north of £1200 a year?

I guess they want to ring-fence this to powerwall customers only?

They’re pretty tiny compared to all the Tesla car batteries, I’m guessing that his what they’re aiming at…

Meeting peak loads spikes by discharging 10% of everyone’s Teslas at the same time.

@igm it would be interesting if you could summarise some of the ‘done properly’ points?

It seems very difficult to work out who is half decent and correct!

@Matt – sorry dont know how mention..

about 7 years, paid £9988 in January.  Assuming some energy price inflation.  Installer forecast 3900 kWh generation for the year and already at 2,700.

Bad day for solar in the SW today. I have to go all the way back to March 8th for it to be this poor. 2.5kWh so far today.

win some lose some – all about the averages.

FFS, delayed sorting our solar as been getting a load of other work on the house, went back to it today only to realise the Scottish Government pulled funding for solar & battery a couple of weeks ago!

Still down here. Solaredge can’t decide what the problem is 😢. Having to chase lots to get any kind of update.

Oh god, that’s not good to say Solar edge seems to be pitched as the premium brand.

It goes to show how sporadic the after support is in the market generally, as if the whole industry seems consumed with installing as much as they can rather than balancing it with a good support network. Just my impression

Yeah it’s not ideal. The lack of updates from the supplier is the most annoying bit. Even a call to say no progress would be better service instead of me needing to chase. I’m partially frustrated because I forgot to charge yesterday before their office closed and now have to wait till Monday.

One positive is the battery is charging during the cheap period so we are at least getting some benefit.

@nixie In practice the 3.6kW export limit is mainly due to the voltage rise caused by the export.
The system sits near the top of the allowable voltage range at no load and as demand (lights, cooking etc) is drawn down the system the voltage falls towards the lower limit.
If on a summer’s day your PV is pushing out export and the demand on the system is low then it can push the voltage over the upper limit.
Not always but it needs checking – hence there is a (fairly minimal) design requirement.

PS – if you want we can do the long discussion around ADMD and diversity of PV

@northernremedy – Borders between the edge of the panels and the edge of the roof, avoiding shaded areas, telling / applying to the DNO, discussing the order of the various bits of kit installed and where the CTs were to get the battery, EV chargers and PV to operate in the most cost effective way as well as safely.
That sort of thing.

I’ve found Solis (my inverter) to be very good and easy to contact, but LG – not so great. I’ve been waiting almost 6months for them to address a fault/problem with the battery management system.

Had the surveyor from Solar Together scheme out today, very helpful, answered all my questions, reckon it’s a go-er! Said the install would probably be turned around extremely quickly as well which is good.

The one question that slipped my mind was the possibility of using the battery as a back-up in case of power cut. It’s not a huge deal (we’ve only had 3 all less than an hour in the 3 years we’ve been here) but it would be nice if possible.
I’ve read (on here) that if your inverter is “grid-tied” (which it is – Solis S6) it’s a no-go, but this is at odds with other things I’ve read such as this ( https://www.solarguide.co.uk/solar-back-batteries-power-cuts#/ ) which to me reads that this function is purely a function of the battery? Which would be a Pylontech US3000.

Anyone shed some light?

Solis you can wire up some emergency circuits into the eps.

That’s what we have.

You’ll need an independent earth and most installers won’t do it. It’s hassle for them .

Watch your prices as well. Pylon batteries are cheap and prices of everything is coming down. Rapidly at the moment so careful comparing to prices quoted on here.

Panels – 400 watt is down from 250 quid at the start of the year to 140 right now….

Watch your prices as well.

Thanks @trail_rat. Where are you looking for prices of batteries and panels pls?</p>
To be fair, the quotes I got so far aren’t even itemised. I’m a little worried that these guys seem so busy they’re not even taking calls to quote, let alone negotiating on what they are quoting

Solar trade sales for one.

But you can get a 405 longi panel at city plumbing for 125 inc vat

Can get a pallet of 10 ja solar 405s for 1350 delivered.

Installers on one of the Facebook groups noting that installations have nose dived. I’d be tempted not to be rushed on the matter right now.

Can get a pallet of 10 ja solar 405s for 1350 delivered.

Blimey!

Hopefully this winter I can add a couple of kWp to each of my places

They will both be ground mounted and completely separate from the existing arrays due to the pre-existing FIT agreements.

One will be south facing to compliment the existing E/W split array.

At the other place it will probably be W facing to get more evening production as the current S facing array switches off a little early.

I would be doing most of the work myself (i.e. not the electrical connections to the CU)

this function is purely a function of the battery?

It’s a function of the inverter which will switch off as soon as it’s connection to the grid is cut.

I don’t have any batteries so can’t comment on how it can be made to work with batteries.

Between the hot water and electric underfloor we don’t really have enough spare production to charge batteries anyway ATM.

completely separate from the existing arrays due to the pre-existing FIT agreements

I’m thinking of something similar. I understand the need to keep the systems separate, but they will both feed the same battery and any exports will go through the same grid connection. Is there some way that you can exclude the FIT export and get SEG on the export from the new system?

AFAIA you can connect the systems after the production meter of the FIT system.

I don’t think you can have any other payment if you receive FIT payments though.

I’m not after the money (I get paid handsomely as we’re on the original FIT rates) but I would use every watt produced!

Is there some way that you can exclude the FIT export and get SEG on the export from the new system?

@Greybeard. I’ve got a mail out to Octopus on the offchance but per another thread on here and another on an electrical forum I fear the definitive answer is no.  Like @sharkbait says, I also recall that the contractor that came round said the same, it’s connected after the original FIT production meter.

You’d think that if you had a 2nd production meter on the 2nd array it would theoretically be possible to report accurately on the export volume of array #2 but as I too anticipate with the right size battery consuming near as damn it everything I generate I’m going to take the loss on the chin.

If I’m honest, I can’t afford the quote i’ve had so far and plan to go thro solar together tendering while waiting 3-4 months to see if prices come down.

Would need 2 mpans

Can’t have 2 mpans at one address

Having done some more digging, I think the situation is that if you install non-FIT capacity you can only be paid for export (SEG or supplier) if you give up the FIT export payments. Some sources suggest you’d have to give up the FIT generation payments too but I think that’s incorrect.

Solis you can wire up some emergency circuits into the eps.

That’s what we have.

You’ll need an independent earth and most installers won’t do it. It’s hassle for them .

My installer left the connectors that I needed behind. Most of the time they run a double socket directly from the inverter as they already have proven fault detection.

The IET mandate a TT earthing arrangement but don’t justify why, especially when you consider that for emergency use an IT configuration is safer.

Some sources suggest you’d have to give up the FIT generation payments too but I think that’s incorrect.

You cannot make any changes to the array that the FIT payments are associate with, this includes changing panels [for more efficient one].  If people were allowed to add capacity without losing the generation payment* then I’m going to borrow and install 2 acres of panels and reap in the payments of 67p/Kwh** they produce as I’ll have them paid for in a few weeks!

* I’m fairly sure you can’t

** or whatever I’m on at the moment – it’s something like that.

Sorry that people have had to reiterate that point btw – I’m not ignoring them but am in the “ask as many people as possible til you get the answer you want to hear” phase 🙂

I suspect it doesn’t change my payback/decision making process and to be fair, only 12 odd years of FIT left and then I’ll be able to. Sounds odd to say but time flies when you’re having fun!

doing a little sanity check

Ive got 6 months to remortgage before i take a big interest hike as my deal ends..

toying with upto 15k extra for a solar plus storage install, 3 bedroom house, using 9-12kwh a day. would be looking at using Agile scheme from octopus, my current supplier

the current ball park on mortgage calcs say it would cost me an extra 130 a month for the 15k, and my last months electricity usage was 80ish.  so 50 quid a month as it stands, assuming i can make it generate enough.. which i will do some calcs in a mo

obviously interest rates, and electricity rates will change… mostly talking out loud until i get some quotes under me

I think this would pay for itself plus a little wiggle room.

I got 18x 405w longi panels plus 4x Hanchu batteries (12.8kWh)  with AC coupled Lux Squirrel inverters for 15k in Feb this year. From what I read prices are now even better esp on panels?

Since early march I have exported 1000kWh more than I have used and with Octopus Flux am making >£100 a month in may, june, July …. compared with paying £120 a month. Our leccy usage is/was similar to yours, but imminent heat pump will change that!

If you can borrow at a fair rate then it kinda makes sense. Have a look into whether AC or DC coupled makes sense for you. We went AC coupled as though some efficiency loss the flex on drawing lots from battery (7kW) made sense to me.

You cannot make any changes to the array that the FIT payments are associate with, this includes changing panels [for more efficient one].

Yes, agreed. I’m not planning to make any changes to that array, or its inverter.

If people were allowed to add capacity without losing the generation payment then I’m going to borrow and install 2 acres of panels

I don’t mean add capacity to the FIT array, I mean add capacity on the same mains connection. Downstream of the FIT generation meters. I know I wouldn’t get FIT payments for it, but I’ve read that if I want to claim export payments for the extra capacity, I would lose all the existing FIT payments. That wouldn’t be worthwhile, so if that were the case (which I don’t now think it is) I would need to work out the payback on the extra panels assuming I won’t get paid for export from them.