Solar Panels and Home Battery

Daviddunlop83

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575kwh here so far in April with 252kwh exported. Turned the battery charging from the grid off a few weeks ago and even on cloudy days it's at 100% before sunset.

Also moved my Eddi boost time to 11am as it can use the battery and solar instead of just the battery. When I have the battery charging turned off the Eddi was drawing 3-400w from the grid as the inverter can only suck 3100w from the battery annoyingly.

I thought the Eddi would only use excess power?
 

KyleR

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I thought the Eddi would only use excess power?
When you boost it or schedule it to boost it uses whatever power is available, starting with PV, then battery, then the grid. As I previously had it set to boost during winter on the off peak hours and the battery scheduled to charge at the same time, it pulled from the grid, but now that I have battery charging from the grid turned off the Eddi was pulling from the battery and the grid as the inverter is unable to provide enough power for the 2.8kw immersion and then base load of the house.
 

mike150

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Has anyone down the sums on hot water?
I’ve had my eddi turned off from day one as (to my mind) it’s cheaper to have the boiler heat water for an hour rather than forgo the tariff i’d get for export…
The boiler needs to be on regardless as the kids take a bath every day and the eddi alone wouldn’t get enough water up to temp.
Good to see rates climbing over last few weeks
View attachment 395050
You could have a valid point on the Eddi.

I actually think it's cheaper to just run the oil boiler to heat the tank and get 17.55p per Kw from Power NI to export rather than use the PV to heat the tank.
 

Daviddunlop83

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You could have a valid point on the Eddi.

I actually think it's cheaper to just run the oil boiler to heat the tank and get 17.55p per Kw from Power NI to export rather than use the PV to heat the tank.

That’s what my solar installer told me rather than installing an Eddi
 

KyleR

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It's all well and good making these decisions on the currently inflated FIT of 17.66p, but what happens in October when it's cut in half back towards where it was last year due to falling energy costs? Last year it was 7-8p, I'll be shocked if it doesn't drop to 10p in October.
 

Crow555

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That was my thinking as well. I would rather my hot water came from the sun and we kept as much of our oil (heating is rarely on at the moment) as we can. Who knows what Mad Vlad does next and how it will affect oil prices? Oil may be as cheap now as just before the war but it's still £200 more than 2 years ago at the same point of the year.
 

mike150

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So last month I used 95.2kw to heat water via the Eddi, now that should be a constant as regardless of the time of year you need the same amount of hot water every month.

95.2 KW in 1 month X 12 months X 0.1766ppkw export is £201.75

Before I got the solar system I estimated the I'd save £200 a year on oil by heating water via PV albeit that was at 80p per litre of kero.

So it's all much the same saving, that said I expect I will have to use the boiler for water in the winter months in the morning and evening.
 

Jason

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Ballymoney
Has anyone got a 10kw system installed? What sort of figures are you doing per day? We are perfect south facing with no shading.
 

mike150

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Has anyone got a 10kw system installed? What sort of figures are you doing per day? We are perfect south facing with no shading.
From my experience on a perfect day at an average sunlight day on a 10deg roof (which is around this time of the year) you should generate 60kw per day. Bear in mind there aren't very many perfect days. Also you'll get 10% more if the roof is at an ideal angle.

I'd expect 10,000kw per year on a 10kw system if it was on my roof or an average of 27.3kw per day.
 

Ghost

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From my experience on a perfect day at an average sunlight day on a 10deg roof (which is around this time of the year) you should generate 60kw per day. Bear in mind there aren't very many perfect days. Also you'll get 10% more if the roof is at an ideal angle.

I'd expect 10,000kw per year on a 10kw system if it was on my roof or an average of 27.3kw per day.
I can tell you now, there will be many, MANY days where you generate nothing or more or less nothing.

My roof has all the perfect angled and facing direction.
 

Jason

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From my experience on a perfect day at an average sunlight day on a 10deg roof (which is around this time of the year) you should generate 60kw per day. Bear in mind there aren't very many perfect days. Also you'll get 10% more if the roof is at an ideal angle.

I'd expect 10,000kw per year on a 10kw system if it was on my roof or an average of 27.3kw per day.
Think ours is a 30% roof, commercial with big span.
 

Ged

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Has anyone got a 10kw system installed? What sort of figures are you doing per day? We are perfect south facing with no shading.

Ive 11ish kw up south west with a shallow pitch (not ideal) and over the year ive done just under 11000kwh.

Heres aprils and mays charts. A great day will see close to 100 or over units in the summer.

345426116_2229090310627589_8774224688916349383_n.jpg
345246178_634092471471923_3425303650142299623_n.jpg


Cheers,
Ged
 

Marynarz

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Ive 11ish kw up south west with a shallow pitch (not ideal) and over the year ive done just under 11000kwh.

Heres aprils and mays charts. A great day will see close to 100 or over units in the summer.

345426116_2229090310627589_8774224688916349383_n.jpg
345246178_634092471471923_3425303650142299623_n.jpg


Cheers,
Ged
What inverters have you got? I am guessing you are generating full capacity in peak sunshine? I believe it's a bit of a con that installers don't say you can only generate 3.6kwh max domestic. Makes me angry actually 🤬
 

KyleR

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What inverters have you got? I am guessing you are generating full capacity in peak sunshine? I believe it's a bit of a con that installers don't say you can only generate 3.6kwh max domestic. Makes me angry actually 🤬
Can you elaborate on what you mean they don't tell you you can only generate 3.6kw? Were you not told what inverter they were installing?

You can apply for 5kw quite easily now, but even without that, if you have batteries you can generate much more than 3.6kw, my highest is just over 6.
 

Marynarz

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Can you elaborate on what you mean they don't tell you you can only generate 3.6kw? Were you not told what inverter they were installing?

You can apply for 5kw quite easily now, but even without that, if you have batteries you can generate much more than 3.6kw, my highest is just over 6.
Nobody told me that my 5.88kwh system will only generate 3.6 maximum at peak times. Furthermore to get the survey done by NIE is £600 or so. No guarantee that they will allow higher generation apparently. My installers did not offer the option to fill out G99 form.
 
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Crow555

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Funny, I just looked at the recent few days on our app and the highest were 3.59 or 3.6kw any of the days. I just assumed it was because our panels are split over a east-west pitch.
 

hutchy_belfast

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I can't believe people spend high 4 figures on this stuff without understanding what it can and can't do? Not as surprised that the suppliers fail to mention the current limitations.
That flat top line is inverter clipping it's just pumping the surplus out as heat.

Edit: someone managed to upsell a colleague of mine away up to 14kW of panels with a moderately sized battery. He spent either 13 or 14 grand on the whole thing. I'm not sure I've spent that on electricity in total in my near 20 years as an adult but he seems happy.
 

-herc-

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Over the last week I’ve been switching appliances off overnight. Ring floodlights , porch motion lights etc etc.

Every day a lot of my usage is from 0000-0600. Yesterday I used 6kw from the grid. 3.5kw was from 0000-0600 before anyone is awake.

Here is this mornings readings. Anyone any idea.

IMG_9933.jpeg
 

FM155

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If that's from one item, it's around 600w so you're looking for something like a computer tower or a heated floor mat under a tiled floor? The only way to definitely track it down is to monitor each circuit from your consumer unit with a power monitor.
 

Daviddunlop83

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N.Ireland
Over the last week I’ve been switching appliances off overnight. Ring floodlights , porch motion lights etc etc.

Every day a lot of my usage is from 0000-0600. Yesterday I used 6kw from the grid. 3.5kw was from 0000-0600 before anyone is awake.

Here is this mornings readings. Anyone any idea.

View attachment 397190

We use about 400-500W with no one in the house. I presume it’s the fridge/freezer, sky boxes, CCTV etc
 

saxo_man

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What is the deal with export payments these days? We’ve the panels in 7 years now and after a couple of years we sort of stopped tracking it daily so I haven’t been following things! We changed our wifi router in 2019 and I forgot to update the inverter so unfortunately have no data for the past four years (kicking myself). I worked out how to do it so it’s back online again now. We do submit our figures for the export and roc payments when required throughout the year. But is it possible to get a different export payment by getting a different rate from a particular electricity supplier?

Cheers.
F3F1F9DD-42E0-4A4A-819C-D38D32415AF6.jpeg
 
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