The Solar Thread

Nope.

I looked at HA and i just dont have the time / inclination atm

We have a Solar Edge system: PV, battery and water heater.

There isn’t much you can configure, beyond the main preferences – eg water/ battery priority. All the technical tweaks or problem solving have to be done via Solar Edge helpline/ whatsapp chat. They are very helpful and responsive, but i’d rather be able to look under the hood a bit more i think.

Now the production has started to increase, and our road got an upgraded transformer that allows us to export, I’m starting to look around at different tariffs. Is anyone on Octopus Agile? The prices are starting to look pretty good now if you can load shift. There is also a new Beta tariff from them called Flux, that is designed for PV/battery owners without an EV Flux

Really hard to work out the relative merits, not least because our system has always been throttled by the export ban so i don’t know how much the house is really capable of producing in the summer.

Oh. I’ve just seen in the small print that they only except 9kwP systems for Flux so that rules us out – although since we have an E/W split, there’s no way we’d ever get to peak.

To benefit fully from the Flux tariff you need to discharge your batteries to the grid, my system doesnt support that. I use Eco7 which is still the best option for us at the moment.

HA is the game changer for me, without it (or something similar) then you are at the mercy of your installer and the limited data access that your vendor offers.

There isn’t much you can configure, beyond the main preferences – eg water/ battery priority. All the technical tweaks or problem solving have to be done via Solar Edge helpline/ whatsapp chat. They are very helpful and responsive, but i’d rather be able to look under the hood a bit more i think.

Same with Huawei, but you can just make yourself Admin and get 100% control e.g. I can tweak all the mains voltage control params and timeouts.

Admin params by Ben Freeman[/url], on Flickr

So on a cloudy February day what sort of proportion of output are you getting. Struggling to get 10 pct for me today 🙁

So many variables….. and it’s a cloudy February day!

TBH as the owner of PV for about 9 or 10 years I’m well past getting excited about the output (well…. mostly) – but I get the “new adopter” interest in what’s happening!

(but about 15% right now)

@sharkbait – thanks I’m interested partly as I’m trying to sense check if things are working properly in a new install. Albeit the chances of rectification are I expect nil unless it’s not working at all as any issue could easily be waved away because of one of the ‘ many variables’ as you say.

So on a cloudy February day what sort of proportion of output are you getting. Struggling to get 10 pct for me today 🙁

Why would you expect more? 10% is fine. you should be able to run the house on half of that and still store some power. Yield for the day would be 4-6kWh. We got 5.5 yesterday and even with two people working from home, cooking dinner, making HW bottles for bed, etc, we made it from 09:00>20:00 on just the solar.

Today, we’ve got clouds and sunny spells, so yield is already at 4kWh…You’ve got to view it on a monthly basis, not daily.

So far in Feb, we’re at 210kWh of which we’ve managed to use 93%. With the extra battery which will go online this weekend, we’ll increase that usage. Best day so far (in the life of my array – Dec 22 > now) was 18kWh.

TBH I think the only thing that could be wrong is a bad connection but I would have thought that would show up as either a massive, or zero, reduction in generation (depending upon single or micro inverters).

Either way I think these things show up better when there’s a clear sky.

I had an ‘issue’ at our other place that I didn’t find for 2 years!!  I installed a diverter but nothing was being sent to the immersion even with everything switched off and the sun being out.  Turns out the installers had fed the output from the inverter into the incoming (i.e. grid) side of our meter – so absolutely everything we generated went to the grid!!!

They didn’t believe me when i told them and had to send pictures.  Oh how I laughed when they had to send a an ‘engineer’ from Norfolk over to the far corner of N Wales to correct it – and pay me the compensation I was taking them to court for!!

(that’s a bit of an edge case but without fitting the inverter I probably wouldn’t have noticed that it was so incredibly wrong!!)

Stupid question alert. If I installed a 5kw array is that a max of 5kw over what time period (per hour, instant?) sorry nee to this and am thinking of heading down the solar route as my oil system is dying big style.

you should be able to run the house on half of that and still store some power. Yield for the day would be 4-6kWh. We got 5.5 yesterday and even with two people working from home, cooking dinner, making HW bottles for bed, etc, we made it from 09:00>20:00 on just the solar

I think your statement should be qualified with the size of your array and location – TBH I’m really struggling to see how you could possibly be generating power at 8pm when the sun set here at 5:30pm!!

Best day so far (in the life of my array – Dec 22 > now) was 18kWh.

Def NOT a 4kW array – my best so far is 6.5kW (but thats on a E/W array and it’s too early in the year for it to come into it’s own)

BTW it would be in a totally un obstructed perfectly south facing roof up a hill.

am thinking of heading down the solar route as my oil system is dying big style.

Which part of an oil system do you intend to replace with solar.

Heating hot water, central heating is already being looked at with a hook up to my existing back boiler on my wood stove.

It would have been quicker to kindly answer my question that question my methods though 😁

If I installed a 5kw array is that a max of 5kw over what time period (per hour, instant?)

It’s the theoretical maximum the panels can instantaneously produce in lab conditions.  The reality is that you will get a margin less than that as the stars rarely align perfectly* (panel production reduces somewhat as heat builds up).

Additionally, chances are the inverter will be limited to a maximum output of 4kW at any one time regardless of the input.

*  In fact, almost never!  Even when the it’s a clear blue sky all day the angle of the sun to the panels in the morning and afternoon will lower the output.  This is why the graph for a [south facing] perfect days generation looks like a hill with the peak being when the sun is highest in the sky – after the peak the generation will decline as the sun moves around and falls.
It’s at this time when a E/W facing array is beneficial as it will start/stop generating earlier/later than a S facing array.  Battery storage has negated some of that advantage but not all.

Thank you

I think your statement should be qualified with the size of your array and location – TBH I’m really struggling to see how you could possibly be generating power at 8pm when the sun set here at 5:30pm!!

Perhaps if you read more carefully you’d be less confused?

you should be able to run the house on half of that and still store some power

we made it from 09:00>20:00 on just the solar.

Perhaps it could be written clearer 😉
Could be read as you were making power between those times!

As written that’s what it says sharkbait it’s not just you.

Fwiw it’s sun angle that’s the killer.

It’s pishwet and raining here today but the clouds are bright due to the sun behind behind them high in sky

We still generating 1kwH currently

Similar conditions in December would yield 200wh as sun has much more atmosphere and cloud to get through

Best day so far (in the life of my array – Dec 22 > now) was 18kWh.

And this is why people should qualify some statements with a description of their array, because this ^ could lead people, who are thinking about spending money on PV, to believe that they can fit a standard 4kWp system and generate more than enough power all year, when the reality is probably very different.

@daffy I’m way below that with 6kw array, split 50/50 se/sw facing. Managed a measly 1.4kw so far today.

Ours is a 5.5kWp array which is almost south facing (SSSW) at an inclination of 30deg. We’re in the SW. cThe lower half of the array is in shade during the very first part of the morning at this time of year due to the neighbours house being slighty up the hill from us and having a higher pitch to their roof.

Since December we’ve generated just over 550kWh.

Looking at joining the solar party, it seems like a no brainer based on quotes so far, but let me know if I’m missing something.

One point to note is we’re in a conservation area (Edinburgh) with about 50% flat roof which is partially shaded by cupola and chimney so those do limit system design somewhat so we’ll max out at 3kwh tops I reckon.

Regardless of limitations if seems like a no brainer, £12k for a 3kwh system and battery, of which home energy Scotland will give £2500 grant and the remainder as a 12 year interest free loan.

Payback period on the system is only 8 years and savings over the lifetime are around £20k so seems like a no brainer, if you pay for it all as grant and loan then you only repay £70 a month on the loan and are saving more than that a month of the electricity bill. Even accounting for payback not as estimated for any reason, it’s quite clearly a good cost saving as well as right thing environmentally.

Am I missing anything?

What’s the size of the battery being offered?

One point to note is we’re in a conservation area (Edinburgh) with about 50% flat roof which is partially shaded by cupola and chimney

Planning?  A flat roof would require a ground mount style frame to mount the panels – that’s going to stand out somewhat! Is the shading going to encroach on a 3kW array or is 3kW the size that will be completely unshaded?

I have an unshaded S facing 3kWp system in N Wales and for 5 months of the year it produces less than £70 worth of electricity per month @ 35p/kWh.

(Annual production averages 3MWh)

Have you factored that in?

Recently had 4.8kWp Solar and 7.1kWh Storage. Lux hybrid inverter allows import and export settings. Paid £9.9K

On a dull feb day I am putting a couple of kWh in the battery at night on Octopus Go, so 15p, and the rest of the day is self sufficient. Generating 3.7kWh so far today has even topped up the battery

Very happy, I have only imported peak rate electricity 2 or 3 times in the last month

SOC by danjwilkinson[/url], on Flickr

ppv by danjwilkinson[/url], on Flickr

What’s the size of the battery being offered?

10kw

Planning? A flat roof would require a ground mount style frame to mount the panels – that’s going to stand out somewhat!

Should be fine, tall narrow townhouses with a fairly narrow street means it’s impossible to see any of the panels on the neighbours, ours would be the same. The guidance on what is acceptable or not is whether it’s visible on the front elevation, which it isn’t.

Is the shading going to encroach on a 3kW array or is 3kW the size that will be completely unshaded?

3kw is the unshaded section.

I have an unshaded S facing 3kWp system in N Wales and for 5 months of the year it produces less than £70 worth of electricity per month @ 35p/kWh.

(Annual production averages 3MWh)

Have you factored that in?

Awaiting the final proposal and drawings through but from what we went through yesterday, yes all of this is factored in. I’ve also got neighbours very similar system to compare against that should give me a good idea of real world generation versus theoretical.

I’ve also got neighbours very similar system to compare against that should give me a good idea of real world generation versus theoretical.

PVGIS shows an annual generation of about 2650kWh for your location (if you haven’t looked already) and it tends to be really quite accurate.

Well Wales seems to be the solar power capital at the moment 😉 My 6.0 KW array was pushing almost 5.1 kw for quite some time earlier. It is a intermittewntly cloudy day here but am on 10 kWhs already generated. Yesterday was 16 KWh total. 218 LWh for February so far and 421 for the year. That is used and stored since I have no export capability. To be fair there has only been a few days of over generation and hence wasted output. A guess would be no more than 20 KWh lost

606kwh in aberdeen for the yr so far on a 5.3 array

@welshfarmer that’s impressive. I would only get that percentage of the installed power on a sunny day in May – but my installation is 12 years old and I think the technology has improved significantly.

…… and the panels will perform better in the current low temperatures compared to warm summer temps.

Certainly wondering if my panel setup is fubar with those generation numbers. Possibly too much resistance on the cable run or other gremlin.

Having had a battery staying at high soc, noticed it’s at the other extreme now- 3 pct which feels too low!

@muddyjames

EW split sucks in the winter unfortunately. It’s only in the last week or so that our battery has been getting much charge. The worst days of january might only see 2 kWh. Last week the sun just seemed to suddenly get high enough for things to start working and we had a 22 kWh day. Will just about scrape 7 today and 300 for the month.

The summer is a different story as we can be generating from 0515 to 2115.

(Oxfordshire, 10kWp 35:65 E/W split, 50 degree angle on roof, 10 KWH battery)

Certainly wondering if my panel setup is fubar

Are you south facing or what? As @lodger said E/W is fairly crap in the winter but starting to get going now.

My set up is 3kw southwest and 3kw south east so not as bad as east and west. Was cloudy all day here with some rain and got approximately 2.5kwh for the day from 6kw panels.

PVGIS shows an annual generation of about 2650kWh for your location (if you haven’t looked already) and it tends to be really quite accurate.

Had not checked, thanks. This figure is almost on the nose of what our neighbours got last 12 months, and installer thinks he can squeeze a slightly bigger array onto our roof versus what they have (it’s the same installer).

My set up is 3kw southwest and 3kw south east so not as bad as east and west. Was cloudy all day here with some rain and got approximately 2.5kwh for the day from 6kw panels.

Hmmm.

My 4kw E/W array produced 4.2kwh and it’s been cloudy/rainy with a couple of bursts of short-lived sun.

Do you have micro-inverters or a single inverter, and if the latter is it dual mmpt?

You’ve probably just had more rain!

The s/w and s/e array are each meant to be on separate input to the inverter. each panel has got a tigo optimiser too.