The Solar Thread

Recently bought a house with panels on, installed back in 2018. Wind is howling today and i can hear rattling/chattering in strong gusts which i assume is coming from them. Only other time i heard it was in storm babet. Is this normal in strong winds or is something loose? If it isn’t normal am i right in assuming this will be a pain/ expensive to inspect?

Not normal. Get someone up there to look at it soon

OK not what i wanted to hear but will get someone to look at it. Been in the garden looking through binoculars and can’t see any movement anywhere when it gusts but quite loud inside from a specific area of the roof. Can’t imagine anyone getting up there before the new year now though.

Probably. The cables banging off the underside in the wind. Especially if they have been up there for. A long time and the cable restrain system has failed.

Or it’s just the tiles moving around.  Ours do this in strong winds.

December update  and annual summary – 5.5kWp array, S facing in the SW.  20kWh of battery storage.
81kWh Generated  (HALF of last year – what a crap December)
550kWh Imported (Wife was at home for most of it, kids were at home for a lot of it, at least 100kWh went into car charging)
19kWh Exported

Running total for the year is ~5731kWh of generation.  We beat our installer estimates by 13%.

Overall, we’re still in profit for the year, but unless the PV yield picks up in January, we’ll be paying at the end of it.

How did everyone do during the recent power saving period?  We got 5600pts, which wasn’t that great.

3.9kw panels, 10.4 kw/h batteries, 3.6kw inverter

some quick math has me co9nsuming 1198 kw since august, my average unit price works out at 1.1p per kwh.. wonder how that will work out over the year, that doesnt include the following:

saving sessions, have taken part in all, i have earned 81,376 points so far (£101.72)

last one 10624

4.14 kwh system.

Wife has been at home since May on maternity. So washing machines been getting cycled daily with nappies and wipes etc.

We have imported 10kwh more than we exported just on top of all the power we used at source.

The 50000 points we got through the December saving sessions has paid for our import usage through December. Just have to pay for the standing charge which will be our first payment to octopus this year.

During a normal non maternity year I think our system is sized correctly

5.7Kwh array south facing in a mountainous valley setting. Powering 2 households and a small farm workshop and livestock sheds. Also have a 14KWh battery storage. I am grid tied but have no ability to export.

Since June last year we now supply power to an internet radio repeater mast on our shed. This has a background consumption of 300w, so 7.2 KW daily or approximately 1900 KWh total over and above for the last 6 months or so. 

Results from 2023 (Not including 1900 KWh usage by the radio mast which is paid at cost)

Solar generation 4490 KWhConsumption 4491 KWhImport from grid 544 KWh 

Expenses at 60p/Kwh = £2700 (generated) – £332 (imported) = £2368

December has easily been the worst month so far with only 85 KWh generated which is half the next worse month of November with 185 KWh. Best month was June with 577 Kwh

During a normal non maternity year I think our system is sized correctly

the volume of clothing you wash as your kids grow does not shink. If you’re lucky they stop pooing themselves but shortly after they find ways of going through a couple of outfits a day (especially this time of year with mud/puddles), and said outfits are significantly bigger.

heads up, saving session today at 5:30!

@andybrad – thanks for the nudge. My best result so far is 3100 pts + 400 bonus – limited by the inverter.

Figures for the year :

(10kwp east west split, 10kwh battery)

we only started exporting at the end of May when our transformer was uprated.

Use – 9.36 MWh

Production – 7.33 MWh

Of which was exported – 3.96MWh

I think we are about break even for the year, maybe £100 in credit i.e. no payment for energy, including standing charges (we are electric only).

So that’s ~£2800 “earned” for the year.

The array and battery were part of the new-build house purchase so I don’t know what they cost. the battery is ~ £6k (inc vat) now

octopus saving session 5-6pm tonight

So we got ours installed at the end of January:

• String one – 10 * 435w inset panels south facing
• String two – 4* 435w east & 4* 435w west
• 6kwh solaredge inverter and Tesla Powerwall

What’s amazed me so far, one week in, is how much we make on a totally overcast or wet day, we generate 4-6Kwh even when the sun doesn’t break the clouds (North Yorkshire).  when the sun comes out we’ve seen 4kwh generation.  Best day so far 16kwh, worst day 1.5kwh.  Powerwall has been excellent, we’ve been self powered for 50% of the time, longest stretch was 36 hours.

I’ve just switched us over to Octopus Agile. I resisted for a while because I thought we’d have to move to either Agile outgoing or fixed, but it seems they are happy to leave me on flux export.

We have 10kwh battery so can avoid the 4-7 peak. as a result, our average unit cost has dropped from 19p to 13p.

I don’t really understand how agile can be so much cheaper – but i’m certainly not complaining! Even the peak time doesn’t go much over the capped rate at this time of year.

that’s a mistake, Flux is a combined import/export tariff, you either need to go on fixed or agile export. expect a correction in the future IMHO

Look at the prices of agile during the fuel crisis, over xmas 22 into 23 😉 then you’ll see how it could be

Check your figures though, most people with solar are saying Flux is a better deal as the weather turns, luckily i think you are only tied into a 30 day contract on smart tariffs

i’d expected to be moved for export, so if it happens i won’t be too disappointed. agile import prices are definitely much cheaper than flux at the moment though – it’s below the flux cheap rate for about 20 hours a day. we’ll probably switch back to flux as the sun starts to come out and we export more. Hope the prices don’t drop too much next month though as the credit we built up last spring/summer mostly paid for this winter.

You can switch away from our Agile Octopus tariff to one of our standard tariffs any time without financial penalty, but you can’t move back to one of our smart tariffs within 30 days

This is the TnC forSmart Tariffs from Octopus, so worth bearing in mind.  You’ll lose at least 2 months a year and possibly longer by the time the switch is made.

@Daffy That’s what I thought, but i asked in an email and got the following reply, which seems pretty unambiguous:

“Thank you for reaching out to us. To switch from Octopus Flux to Octopus Agile, you can simply request the switch through your online account. There is no delay before you can switch back if you decide to do so in the future.

If you have any further questions or need assistance with the switch, please let me know.”

I am on fixed output (15p) and just moved to tracker for 17p import.

i dont see how you can make agile work unless its big batteries?

Agile and electric car here. No special usage we just charge the car overnight or when we see pricing go very low (plunge).

average price paid over last 12 months with approx 7200kwh’s is 4.9p / kWh. Last 6 months is 4.5p / kwh

Our panels got fitted yesterday. 16 of them on the roof of the shed and now all we need to do is wait for the electrical bloke and his mate to turn up with a bunch of cables and a 10Kwh battery system and wore the whole lot together.

Nice.

If anyone is interested, I’m about to sell on my LG RESU 6.5 battery pack.  It’s a low voltage DC battery with a usable capacity of 5.9kWh.

This is the current generation of pack and is highly efficient in all weather conditions.

It’s 10months old is still at 98-99% state of health and comes with the brackets and connectors to fit it.  It was installed outside, but in an enclosure so whilst it has signs of use, they’re highly minimal.

I’m only selling as I’ve bought a bigger one.

£1100 plus postage or collected/meet up.  I’m near Bath.  It cost over £2700.

Finally… The “Chaps” are finishing off the day’s work work installing the inverter, battery and assorted cabling that makes up our solar installation. This comes about a week after their crew came and installed the roof framework and the 16 panels that we have on the shed roof.

After a slight hiccup with the box for the 10Kwh battery (built to the size of the actual battery and not what the battery _requires_ to prevent overheating), our bit of the installation was just to make sure there was WiFi for the Huawei inverter to connect to which, thanks to a long Cat6 cable and a new AP, it can.

I just need to put the AP somewhere out of the way, but still in sight of the router, and tidy up some cables and it should all work fine. If there was sun.

has anyone had any info about next month’s Flux rates?

I think the cap has dropped 15%, which would take the peak export to about 25p/unit, but I don’t know if that’s how it works.

Had an email today

Import changing to 14.794/24.656/34.519

Export changing to 5.373/15.149/25.098

SC to 61.268

On the Octopus forum there’s been some muttering about how the drop in rates but increase in SC is going to actually increase the amount low importers will pay each year.

Yeah, mine’s gone up by £34/yr. Object to having a standing charge that’s 78% higher than London when the electricity is produced in our backyard and posted down to the South East.

Slightly regretting the order of an extra battery and bigger inverter now. £2,900, but I don’t like the batteries under the stairs. I was tempted to do it myself and save £1000, but not keen on cutting and re-terminating the solar PV cabling. High voltage DC scares me a lot more than AC, and I don’t think “wait until it’s dark” is in the IET guidelines.

I have a 10.25kWp solar and 6.9kWh battery installation booked for early April. Just trying to work out the best tariff… is Octopus Flux still the go to?

Object to having a standing charge that’s 78% higher than London when the electricity is produced in our backyard and posted down to the South East.

Think about how we feel in north of Scotland then. When largely  the green energy is produced here and sent daan south and they want to up our standing charge to pay for the new mega pylons they want to put in our gardens to get the power down south .

59.031p a day.

 And I’m not “allowed” a larger inverter……

I’ve been looking for quotes for solar panels recently but it’s worse than double glazing, for pricing and tactics.

Could those of you who’ve recently had solar panels fitted please quote the cost and installed kWH? @Northernraider @Willard

Thanks

feel you on the cost and difficulty benchmarking.  We used a company called green building renewables.

North Yorkshire. 8.7kwh inset panels, 6kwh solar edge inverter, solar iboost and Tesla power wall. £17k including scaffold.

I’ll try and dig out the costs, but it will be in SEK and not UKP

£8k for 12 panels, 3.7kW inverter, and 5.kWh of battery storage about 18 months ago. Biggest single expense was the scaffolding.

If more than 3.7kW you may need a G99 application. Northern Powergrid charge £680+ VAT for the assessment based on their website. However, my installers did say that they don’t always charge but it was unpredictable. If you have a lot of solar nearby there may be issues with export, but you can still use the full output privately.

If you have a plug-in socket tester with a voltage reading (or your smart meter or car will show you), then you will hit issues if it’s above 250V on a sunny day as your inverter may disconnect.

Northern Powergrid didn’t charge us for g99, but they did insist our inverter capped us at our export. So we are capped to 6kw

but they did insist our inverter capped us at our export

Your inverter is simply limited to a 6kW output [into your house] surely?

The inverter has nothing to do with the amount of power that’s exported.

Your inverter is simply limited to a 6kW output [into your house] surely

No it’ll be export capped at 6kw.you can sometimes get a software limited export approval to have a large inverter with a limited export – but seems to be rare they seem to want to limit the hardware.

It’s a nonsense though. I’m capped at 3.6kw export “because infrastructure”. But everyone around me could put 3.6kw solar on their roofs and “infrastructure” would still be overloaded.

But half those houses(or more) are in the north lee of the hill and get about 15 minutes of sun a day so solar would be a horrible investment for them

But what can I say….. No one’s ever checked – which is probably why they want to insist on point one beinga hardware limit because I for one would have no qualms pressing a few buttons and making full use of the Hardwear.

We live on a new-build estate of 25 houses all with above average arrays. It took 2 years to build all the houses and while SSE accepted the first 9 houses for export, they refused the rest. The developer had to pay to upgrade the transformer to accept the export.

Sounds fishy to me, if it’s capable of delivering the power to that number of houses I’d have thought that the pipes would be big enough to transport the juice in the other direction. (Can you tell I’m not an electrical engineer?)

There was talk of installing a 500kwh grid storage battery as part of a local experimental program but it never materialised.

Anyway, it was eventually approved 18 months after we moved in on the basis of the max export from the specified inverters – in our case we are limited to 6kw.

@sharkbait – if the inverter can only deliver 6kw, surely that means we can’t export any more?

@ransos with 10kw/p you will be producing more than you need for a lot of the year so your focus should be on maximising your export price, which means Flux. The exception might be if you are a high mileage EV driver as flux off peak window is short and not that cheap.

We are an electric only house, without an EV, and energetically self-sufficient from mid April to mid October including heating and hot water so import prices are less important. For the “shoulder” months, agile is cheaper though.

Thanks @lodger. There was a mistake in my post, it’s ten panels of 425W each so 4.25 kWp. My annual electricity consumption is about 3,800 kWh so we should generate roughly the same, obviously not at the same time. We don’t have an EV.