Solar panels and battery - any real world reccomendations?

[HungryHippos]

So I have the worst of both, flat which would be good for south (but I suppose they could be tilted, but would look awful from a distance.)
And then East/west I have a garage roof pitched.
Assume I could get an install for 10k, it would definitely take years. We use about £2800 a year elec on current projection. Assume I had an install even generating half that (over 3500kwh per year, not sure if doable), it's going to take 7 years to pay back by my very quick man maths.

You could install the ones on south as flat for aesthetics but it will do less generation for sure. Not like it would be 0 though.

MKW sent me this earlier.



Flat tilt of basically 0 degrees on S facing is about 84% as good as 30-40 degrees. If you can add a slight tilt it will help a bit.

My roof is 45 degrees so I have S facing doing probably near to 100 % and W facing at more like 75%.

 

[Troop]

What is your total capacity?

I have another 2.5KW portable pack(105AH x 8), so 17kw.

Plan to add another 14.4kw, I have an old large Bread oven in this old house that needs filling with batteries

 

[HungryHippos]

I have another 2.5KW portable pack(105AH x 8), so 17kw.

Plan to add another 14.4kw, I have an old large Bread oven in this old house that needs filling with batteries

I only wonder as if your usage is low and your current batteries go the distance, what is the idea behind adding more?

Me, I'm like "yep need more batteries", whilst you're more "I have all the batteries in the world!"

 

[Ron-ski]

You shouldn't mount panels at less than 10 degree of tilt, otherwise they don't self clean, you get dirt collecting, then things start growing.

 

[Troop]

Redundancy, use the grid even less, might even go off grid, the standing charge really irks me for some reason.
I always have to have something I'm building as an ongoing thing, I have always been like this.

Not doing if for financial reasons.

 

[Troop]

You shouldn't mount panels at less than 10 degree of tilt, otherwise they don't self clean, you get dirt collecting, then things start growing.

I like 60 degree tilt, less production in Summer, when most have more power than you need, more in Winter, when you need all the help you can get for solar.

 

[SoliD]

We opted to have a smart meter installed in 2014 when first offered. It was free, so why not? The smart element died in less than 2 years and meter readings went back to normal. 18 months ago when we had a load of changes, I looked at getting a new one. Yes I could have one but would have to pay. "How much?" I asked. £300-£400. How long until it will be replaced anyway was the next question. Not until it is 10 years old came the answer. From memory the old meters with dials were good for 25 years. Smart meters, smart motorways, and smart phones. The only smart thing about them all are the people who persuaded us all to get them.

Old dial type meters were usually replaced where possible in a 10-12 year cycle, so no real difference.

 

[Peteronthesouthcoast]

Old dial type meters were usually replaced where possible in a 10-12 year cycle, so no real difference.

A long time a go I lived in London. My flat had 2 meters that had not been changed since it was built some 14 years before I moved in. I was there 6 years and they were never replaced. My daughter has a 3 bed semi and uses about 3-4000kw/year. A couple of years ago the meter went "round the clock". It seems likely the meter is 20 years old. Looking at her radiators for her central heating, I think they are at least 25 years old, so the central heating/hot water is all gas, making me believe that the house has never had a high electricity use

 

[Peteronthesouthcoast]

Positioning of Solar Panels

Near us is this house. https://www.rightmove.co.uk/properties/130160285#

It sold quite quickly after being reduced a bit. Having solar panels in the garden will not be to everyone's taste. I would be tempted down this route if it was the most viable option. I would also look at mounting the panels a little higher and having mirrors in front to reflect the light up as they do in many places abroad. As Ron-ski said having the pitch higher boosts winter production when you need it most, and mirrors would also work

 

[b0rn2sk8]

I've seen that you can get ground mounts which you have a changeable pitch, that would make a fair amount of sense in the UK.

You essentially shift them by a few degrease every month to make the most of the height of the sun.

 

[rodders]

Well they are here, solar edge here we come!

 

[Hawk Tuah]

Damn. The 5kw battery is charged already. Currently got some fan heaters on (and central heating off) to save exporting to the grid for nothing.

Found someone nearby selling a year old 3kw Pylontech battery - so going to add that on at the weekend.

 

[Freefaller]

Damn. The 5kw battery is charged already. Currently got some fan heaters on (and central heating off) to save exporting to the grid for nothing.

Found someone nearby selling a year old 3kw Pylontech battery - so going to add that on at the weekend.

Although I'm out I set the washing machine and dishwasher on and put the slow cooker on.

The cleaner did their deep clean today rather than their usual clean, so got them to go mad and use all the high draw appliances etc.... Still going to max the 9.5 battery today...

Is a second battery sensible? Or should I just accept I'll export to a certain degree?

 

[Mercenary Keyboard Warrior]

Although I'm out I set the washing machine and dishwasher on and put the slow cooker on.

The cleaner did their deep clean today rather than their usual clean, so got them to go mad and use all the high draw appliances etc.... Still going to max the 9.5 battery today...

Is a second battery sensible? Or should I just accept I'll export to a certain degree?

You need to run some numbers.
How many years usage/generation do you have?
If you have a years then you can look at what you buy in when and export when.

Personally based on my modelling I think the optimum battery storage is between 50-75% of daily usage.
Of course its also affected by tariff so there is no right and wrong here.
The equation is constantly shifting.

When I looked at adding another 5kwh it gave a payback of 10 years, with a warranty of 10 years. Didn't seem worth it.

Even with my solar generation total being <50% of my annual usage, and batteries, and a solar diverter I still expect in mid summer to be exporting

 

[Freefaller]

Yes that's sensible. I'll work it out. I think the payback of another battery will be negligible.

Even in the summer I'm going to fill up 2 batteries.

@15p per kWh although not great it'll effectively be "free" in the summer months.

 

[rodders]

All installed, have to wait for the office to map all the panels and setup all the app, then they'll give me all the info.
I can see on my smart meter it's working though, made more peak today than last summer!

My only gripe is they did a terrible job as putting the pigeon mesh back on, it's up there and shouldn't move, but looks crap.

Now for the clever people, I understand that the system maintains a 400v constant voltage and the optimisers adjust the panel outputs to suit, when shade hits?
I thought they might change to 1 string, but they've kept the two strings (4 cables coming down) and then joined then in the DC isolator.
I could go and look actually, but I wonder if they put them in series, as only 1 string from the isolator to inverter.

 

[Hawk Tuah]

Although I'm out I set the washing machine and dishwasher on and put the slow cooker on.

The cleaner did their deep clean today rather than their usual clean, so got them to go mad and use all the high draw appliances etc.... Still going to max the 9.5 battery today...

Is a second battery sensible? Or should I just accept I'll export to a certain degree?

My one battery was 4.8kw, and it didn't last the evening. So adding another 3.6kw makes sense for me.

Not really a case of filling it, it's more that is lasts our typical usage. I wouldn't imagine adding to 9.5 would be all that beneficial - depends on your use.

 

[Freefaller]

My one battery was 4.8kw, and it didn't last the evening. So adding another 3.6kw makes sense for me.

Not really a case of filling it, it's more that is lasts our typical usage. I wouldn't imagine adding to 9.5 would be all that beneficial - depends on your use.

Problem is in winter when we use the oven or hobs in the evening it chews through the battery. But more often than not if it's at 100% before we stop generating even with oven use and hob use we can have charge left in the morning. Come spring I'm hoping this will be more regular as the days get longer.

Don't get me wrong I'd like to ideally max batteries in time for the evening but also exploit our energy usage throughout the day. When I am at home I use high draw appliances - because that's the point!

I'm happy to export after those conditions are met. If I'm exporting £1-2 worth a day in Feb. I'm guessing that'll happen at least 10 days a month for 3 months in summer. That's £60 for nothing. Find it hard to get upset about that.

 

[Jediben]

Hi guys, I've a quick question. I have just had 11 panels with capacity of 4.4kwh and a 3.6kw inverter installed. We also have a 5.32kw Sunsynk battery. I understand additional batteries can be installed. Is it possible to mix and match these batteries (I.e. add a 5.12kw synsynk battery as a slave?)

 

[Freefaller]

I think they may have to be the same make so that the BMS can talk to it - but I may be talking cobblers - there may be a universal standard for comms for batteries. In terms of capacity, no they do not need to be the same capacity.