The Solar Thread

Weird. Lets me send a single line of text. But not the text I want to send

Following my off the cuff thought of degradation on 7 y.o. system, prompted me to look back at the data…

Year Mains Solar iBoost
2018 2211 3586 1518
2019 2972 3786 2245
2020 3010 3690 2199
2021 2721 3635 2093
2022 2199 3764 2291 (to 9 Dec)

So actually, I can stop being paranoid about panel degradation!
On the iBoost, we only moved in to the house full time September 2018, the 14 months prior to that the place was being ripped apart having total refurb. Also looks like we’ll end the year on ~2400kWh for mains leccy, like everyone else we made an effort to reduce usage this year. (Edit : Excel cut’n’paste formating still poor)

3.6kwP 260 degrees orientation 6. something Kwh today. Lovely sunny day but very cold which is beneficial for generation. System is 12 years old so not too bad really.

managed 10 Kwh today from mine. 4.8 KwP on due south facing 40 degree roof. In a narrow valley so sunrise over the hill is currently 10.30 with sunset around 3.30

Full moon and clear skies yesterday evening and I found myself strangely delighted to see my system was generating 1W, yes, that right, 1 whole watt of clean green electricity, at midnight…

🙂

We made 1today and 12 for the month to date. It’s been grim and at best grey.

We made just 54kwh in Dec last year but ramped up quickly in January to 140 and 270 in Feb then ran at 500ave through to October.

im averaging 1.2kw a day huddersfield.

The last 2 days have been bright and ive seen the output just to 800w instantaneous where as its usually 200w. this makes me think the low sun is basically meaning there in shade all the time.

going to keep an eye on it.

We made 1today

What kinda magic system do you have……only got 0.5 today.

7.18kWh today in Derbyshire. 3.85kWp system facing SSE at about 40 degrees. Almost cloudless day but the low angle means one of my panels is in partial shade all day.

Full moon and clear skies yesterday evening and I found myself strangely delighted to see my system was generating 1W, yes, that right, 1 whole watt of clean green electricity, at midnight…

Can you still claim the FIT payments if you’re moonlighting?

Has anyone got either a Solax or a Givergy battery? Any good?

We’ve got a givenergy system; I’ve been very impressed. The web app or phone app is good, with real time updates if you’re home or five minute updates if you’re not, power and energy graphs over different time periods, and a load of options to allow you to tune when and how the battery is charged and discharged.

It all works over their cloud system but apparently the inverters talk modbus and people have got raspberry pis and things talking to them.

@footflaps

It’s very dependent on angle and orientation at this time of year. Our 9 east-facing panels generated almost nothing today because the sun never got warm enough to burn through the frost on the panels. The west facing ones did better, and by 2pm we had bursts of 3kw, but only managed a total of 6.3.

Our neighbours over the road have 20 ESE facing panels and they only got about 2kwh for the day.

I, personally, have expended hundreds of Kwh of mental energy that would have been better spent just working and not fussing about optimising a few pence worth of electricity!

I, personally, have expended hundreds of Kwh of mental energy that would have been better spent just working and not fussing about optimising a few pence worth of electricity!

But where’s the fun in that 🙂

Our solar installation progresses.

Roof now has 18 panels, 7.11kW iirc.

Shifted from on roof to inline setup when
1. Physical roof measurements meant a different panel distribution and number from original satellite guestimate
2. Roof needed redoing rather than repairing
3. Slate breakage was at 50% rather than an expected <20%

Roof work, aside from some pointing, finished yesterday. Looks neat.

Tesla Powerwall got mounted on the side of the house this morning.

Expecting work to resume in the new year.

I, personally, have expended hundreds of Kwh of mental energy that would have been better spent just working and not fussing about optimising a few pence worth of electricity!

Yes, I spent the first week just endlessly looking at the graphs and was considering adding optimisers, but they are out of stock right now. However, I’ve now lost interest and just let it do it’s thing. Plus the scaffolding has come down, so now it’s too late to change anything!

Slate breakage was at 50% rather than an expected <20%

I was surprised they broke – the installers turned up with loads spare and had to replace quite a few. Slate roof is only 25 ish years old as I had the whole thing redone shortly after moving in. When new, I remember running up and down the whole thing in trainers and nothing broke.

surprised they broke

our roofers were surprised at the breakage rate. The slates on one roof part they said were noticeably thinner and more fragile than on some other parts.

The roof was allegedly replaced within the last 50 years. 🤷🏻‍♂️ how many of the original Victorian slates were reused then. Victorian construction methods and materials are not always great 😑

10kW+ yesterday from my 5.6kW PV array. Today looks even better but unfortunately snow cover making them useless…

Quick Q @Surfer: Did you apply for and get permission for a 5.6Kw array or is the inverter limited to 4kW output?

(probably the latter but just curious)

My E/W array is shite in the winter…. just 3.6kWh yesterday 🙁
Definitely need to get a couple of south facing Kw in the paddock.

For the benefit of lambchop, I’m currently looking into a solar install (I live in South Devon). The best quote so far is a local installer, offering this for about £12k:
– 5.525kW solar array
– 13 Trina Vertex S 425W solar panels
– SolaX Triple 5.8kWh battery
– All the rest of the gubbins (inc scaffolding & install)

I have asked him to look at an option for optimisers too as our roof is a bit complicated and some panels may be shaded for some of the day. Of of the bigger firms was trying to sell a solaredge system, but googling them throws up lots of unhappy customers and they cost a good chunk more than other options.

Any opinions from the STW massive on this setup?

anyone got installer/supplier reccomendations in the south east? Brighton area specifically..

@sharkbait retrospective approval/informing for my array, yes 3.7kW inverter although it looks suspiciously like the 5kW model and I noticed I was using >4kW recently and was not drawing from the grid…. I need to double check the model number.

Being really lazy here… has anyone got a good Excel model for calculating benefits over time for a solar install?

@thinksta noticed yesterday loop have a solar benefit modeller. Think you need to link your smart meters so it’s based on your usage.

Interesting – is Loop a kosher thing, or just a way to get and sell your data?

Home Assistant is your friend. I have it set up in Virtualbox at the moment on my mac using a Modbus connection. My setup is Foxess and their app doesnt show accurate PV, it adds the PV to your overnight charge. With HA you get an accurate figure. I just model that in a spreadsheet. I am sure I can output it from HA not worked it out yet.
This is yesterdays (I only set it up last week) and so far highest PV of 10.7kW.

It’s a sunny day (albeit it was snowing when I rode to work this morning) – how’s everyone doing?

This will be the first day since our array went live (November 21st) and the battery was installed (December 9th) that it looks like we’ll get a full (12kWh) battery. It’s only 12:30 and we’re at 83% and charging at a rate of 3kw/h The array is currently generating about 3.3kW (or around 60% of capacity). I’m oddly excited – I don’t think we’ve ever made it past 75%.

its not sunny here – but by the 10th jan id made more power than all of december …..

It was a sunny morning earlier, but it looks like the snow on our panels finally melted just in time for the sun to go in!

Tuesday (17th) was our best day recently by far, we did 16kwh instead of the usual 2-4 we’ve had for ages. I’m trying to persuade myself I can see the daily totals start to rise again as the days get longer…

only getting 1.4kw a day due to shading from my neighbor thats significantly worse than initially expected 🙁

the usual 2-4 we’ve had for ages.

Thats a hell of a range. I had just over 10 which was the highest so far but seldom dropped below about 5 on average. How big is your array?

The highest we’ve had since activation is 13kWh, but we’ve had a LOT of rain in January and so many of our days are 2-4kWh too. 5.4kW array – SSE facing. No shade after 10:30.

November 21st-30th was ~75kWh
December was 132kWh
January so far is 95kWh.

Truthfully, those are better than I expected.

Ours is 8kwp facing south east. We’ve had a lot of dreary days when it peaks at about 800w but the days are so short that it doesn’t really do anything until 9:30 then it’s gone again by 2:30. We’ve done 105kwh this month.

Worst day this winter was just before Christmas at 0.51kwh, can’t do much with that!

My issue now is that having a non-grid-tied solar system, my batteries are full by midday and the solar just switches off as I have nowhere to export the excess solar. The other day I was getting 14 KW daily total and the batteries were still not quite topped up, now I am only gettting 8 KW a day, although the days are brighter, sunnier and longer. I have plans afoot to connect in my brothers house which will use a bit more and maybe then add immersions and do more cooking by electric.

My December total was 111 KWhs, January so far is already 93 (plus at least another 10 KWh from yesterday and today I was unable to use or store).

Those of you with solar batteries – what levels of discharge do you allow and at what rates?

Those of you with solar batteries – what levels of discharge do you allow and at what rates?

All controlled by the built in BMS (Battery Management System), which stops you knackering the cells (Huawei). Inverter can manage 3.8 KW IIRC.

ive got a pilontech 4.2kw. it will discharge at 3kw,

interestingly ive noticed that if i charge it to 100% from the mains then use it thoughout the day i find i use less energy overall ! still testing it for the next few days .

So our LG is a 13kWh battery with a usable capacity of 12kWh and will discharge at 5kW (or 7kw as a pulse load), but the inverter drops the rate of available discharge to 0.5kw below 25% and and 0.125kw below 20%. At 10% the inverter will force charge the battery to 20% from the grid.

What I’m interested in is if discharge protection should be % based or capacity based as the rates on the inverter are just defaults. 20% of my battery is almost 2.5kWh remaining whereas 20% of a 3 or 4kWh battery is 0.6>0.8kWh…see what I mean?

Can I zero it on the inverter as the battery has its own control system?

what levels of discharge do you allow and at what rates?

default was 20% and minimum is 10% so using the tried and tested logic I set it to 15%. My batteries are in the garage and I have had some unusual activity which I am assured is due to the cold but generally mine have behaved themselves.
I have a 5kW Inverter ( I think it should be 3.7….) so that is the charge and discharge limit.

see what I mean?

I assume your app allows you to change this? If so I am sure there is a point at which it will go no lower. Mine is 10%. This is an indication of what your manufacturer recommends and is controlled by the BMS. I found useful advice on a facebook page for owners of my model (Foxess) have a look if there is one for yours.

Just had a look at the BMS settings:

BMS Config by Ben Freeman[/url], on Flickr

Has anyone added additional battery capacity to their array after installation? Did you need to notify the DNO?