Going off grid :)

[makeitfit]

Probably one for Rick but here goes
It looks like I might have scored a grant to get solar panels and inverter.
This is for my REWORX shop. It's my upcycling, reclaimed and bespoke interiors project, more of that again.
4kw system
The idea is to try and store as much as possible in batteries and use that to run my lighting displays in the shop.
Pretty much all of them are LED
Anyway, it's 24v and I guess I'll need many 1000 s of amp hours :augie
What do I look for ? Budget is max £1200
Thankyouplease

 

[solarman216]

Is that budget for pv panels, batteries and inverter? bit on the low side, youwill not get much for that sort of money, but why the inverter if you are running nothing but lights? Rick

 

[makeitfit]

£1200 is the bit we have for the batteries
Just checked the spec
Briefly: 3kw inverter charger with built in mppt solar controller.
ac/dc isolators, consumer unit and ac input and outputs
12 x 320w solar panels

 

[makeitfit]

2v 775a/h GNB traction batteries 2016
12 off @ £625 plus vat plus delivery :doh

 

[solarman216]

I would need some reliability data for an all in one box inverter/charger(from the mains) and solar controller (also a charger) is the inverter pure sign wave, Rick

 

[solarman216]

The batteries are a bit dear for 5 year old, Rick

 

[Fez_uk]

Lithium mate, Chinese ones are getting better and better. Remember you can discharge them more so don't just look at the amp hours. Think max you can discharge a lead acid is 50%? I think lithium is more like 70%?

Check this guys youtube out for some ideas - https://www.youtube.com/user/greasybrothers

 

[panelbeater]

i looked into the chinese batts and concluded it was not worth getting them inported as some already here were not much dearer.you can take them to almost o volts as the built in brains cut off power out completley,the good thing about them is they output full volts not a reducing volts and take a really hefty charge so get fully charged fast but you do need the correct charger for them.i wanted 2 for my caravan.

 

[solarman216]

Ordinary lead acid 50%

Full traction 80% but almost every day for at least 15 years

Li far too expensive, plus they have built in regulators so will give no warning but just cut off when reached safe discharge level, big problem with these also is if one of the regulators fails and a cell discharges below 3v it will be permanently damaged and a fire risk, Rick

 

[Fez_uk]

Depends on what Battery system you have, You can build your own and choose a decent Battery management system where you can tweak the settings and does different things at different points/voltages.

Probably a bit over budget for pete, But certainly not too expensive.

 

[solarman216]

What batteries you looking at Fez as I cannot find anything that is not an arm and a leg with ridiculous specs? Rick

 

[Fez_uk]

When I last looked it was about £80 per Lithium cell (3.3v 120ah). Might be cheaper or more expensive now (Depending on exchange rate, taxes, Import fees etc)

So would need minimum 8? For a 24v 3kwh system. £80x8= £640
For a decent system times by 4. 12kwh = £2560
Battery management system £150-200+
I only briefly looked into it, Was surprised on how much prices have gone down.

Now this might be way more than a traction battery setup, I wasn't aware they can be discharged so much.

 

[solarman216]

Mmmm that set up would give me 480 Ah, currently running 800 plus Ah at a lot less money, 480 would not be enough for our current needs and I do not think from what I read about overall life that I would get the 6000 plus charge discharge cycles that I get with lead acid, thanks anyway Rick

 

[makeitfit]

Well I'm now the proud recipient if one resilience grant
Next problem is to actually find some batteries.
Procrastination over

 

[solarman216]

Before you start looking for batteries you need to establish your amp hour requirement, this will be based on your average amp hour draw and the output maximum of your solar array, plus how long you require to be able to function on one charge cycle, hope this helps, Rick

 

[solarman216]

Oh and forgot to mention you need to take into account the quiescent current of your inverter, typically 0.5 amp for a good one some draw more so over 24 hours = 12 amp hours but of course you can reduce that by turning the whole thing off when lights not needed, Rick

 

[solarman216]

What happened with this little project then Pete? Rick

 

[makeitfit]

Well then, I do now have the panels and inverter package.
I've recently bought an old Tesco fridge back for storage. The plan is to mount the solar panels on the roof of said tesco box.
Council planning needed now ��
I'm still to actually buy batteries mainly because the summer season kind of got in the way ����*����

 

[solarman216]

Can you not mount the array on an existing building, no planning needed for that unless you are listed or in a conservation area, Rick

 

[makeitfit]

I'm using the tesco box as a storage unit. It's meant to be classed as a temporary structure but that only works for domestic situations. I've been told as its business related and accessed daily I'm already in a grey area !
It's difficult to find out properly without asking the council !!
If I could put a pic up you'd get the jist.