DIY Solar panel setup on a budget

the backup generator building for the pa hospital in brisbane is simply full of diesel generators.

i spose they could have used batteries. ...

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so many options to choose from.
let's see. you have lithium. or lithium.

or fossil. or fossil.

 

just picked up 18 x 370w panels and a sma 5kw inverted all less than 4 yrs old for $650. These panels will go on my shed roof on opposite orientations but get full so most of the day.

 

just a FYI for peeps, danger pixies!

 

I spent a few good hours using sunny design. Switched out a sb 4000tl-20 inverter (11232kwh with 54 panels, 10370kwh with 44 panels) for a sb 5.0-1av-41 inverter ( 11358 kwh with 44 panels) disconnected 1 string off 10x190w panels on my shed. This system now has 2 strings (8x175w) panels ne 30% inclination + 1 string (8x190w) panels ne 0% inclination on one input, and 2 strings (10x190w) panels on sw 30% inclination.

The 370's are going on my shed roof. 2 strings of 9. Opposite orientation at dusk and dawn but full sun most of the day. Will run a hybrid inverter battery system for my server rack and shed. Initally on PV panels first, then add batteries.

 

ouch, this was a costly mistake.

 

anyone after panels in Bris?

https://www.facebook.com/marketplac...icks&referral_story_type=top_picks&__tn__=!:D

$20ea (not my ad)

 

New system is doing 2.6kw on a cloudy and overcast AF day in Brisbane. 6.6Kw. Sunny days right up to 5Kw export.

Thinking of now adding a solar battery. Would need to replace the inverter though. Previous bills were 350 a month and I don't have choice of providers so that's 4200 a year to go against ROIs

For the battery - DIY 48V 304ah is the idea. Anyone ever DIY'd the battery? Costing wise 6-7k for 15kwh. Those EVE cells are cheeeeap. I would probably replace the inverter with some victron gear as it's been amazing in the 4wd.

 

you'll never get certification for a mains connected battery, you'd have to set up an inverter and then cable to each device to use it, and the battery would need to be in an external structure with deep underground cable runs.
it would be VERY difficult to get it certified to meet current regs.
https://www.youtube.com/@HBPowerwall has gone through the shit show that is required, it was a nightmare.

anything over 1kw storage is deemed "high voltage" pretty much, and has crazy arse requirements.
making it simply uneconomical to try.

then, there's house insurance.. the true mine field for home storage.

 

1kW high voltage ?

ummm make that make sense lol

I have 11kWh of battery, but 12 volts... so it's household safe.

also, met HBPowerwall irl, good bloke

 

it's easy to make it make sense, what constitutes "high voltage currently, I believe, is anything above 48v (I've forgotten the shit I read already it may be 52v) at that voltage, you can't have anything more than 1KWH of storage (DIY) that is in any way connected to the grid. (thats not certified AKA retail battery systems installed by qualified personal with certified inverts/charger/gear what have you)

I'll try and find where I read it and post it.
currently a basket case with fibromyalgia flare so it'll be when I can function again.

 

all good focus on getting better first before internet discussions


but to discus, the way the post was, it didn't say what voltage of the storage, just the capacity itself and well a car battery can supply over 2000Amps of current when shorted out...

https://electronics.stackexchange.com/questions/246085/how-many-amps-can-a-car-battery-supply

but yeah most storage for homes is 48V and if i remember right, i think there was an update recently, but the limit was 120v DC for wiring up things without a license for laying electrical cabling.

https://assets.cleanenergycouncil.o...e-Guidelines-Iss-13_Apr-2019_2021-Warning.pdf

4.2 Low voltage (LV)
4.2.1 All low voltage (LV) work: >120V DC or >50V AC shall be performed by a licensed electrician.

so according to this the limit is 50V AC and 120V DC

I think they stuck with 48v as it's below 50V AC, even though it's DC power at the battery itself, the number 48 lends itself to being under the limit for either type of power delivery so anyone doing the work complies.


edit: further reference.

https://www.eess.gov.au/wp-content/uploads/2019/04/003-Equipment-Safety-Rules.pdf

These ERAC Electrical Equipment Safety System Equipment Safety Rules (hereafter
referred to as “Equipment Safety Rules”) cover all new electrical equipment with a rated
voltage of:
a) Greater than 50 V AC RMS or 120V ripple-free DC, and
b) Less than 1000V AC RMS or 1500V ripple-free DC,

 

If that is the case the plan in my head was 48V nominal so classed as ELV. So that would not fall under that regulation afaik, connected to a victron multiplus or similar around the 8kva range. Current demands could be up to 250-300a though so some investment in copper and buss bars to be had. Toyed with the idea of an old tesla battery, but not going anywhere near HVDC.

I'm not a sparky but I've been dicking around with electrical and learning on my own for 20 years, few SG tesla coils and other random cool and interesting projects out of boredom, I own a copy of as3000 and any AC work I do myself I have my brother who's licensed validate my shit for a beer or 6

One thing I refuse to even go near are HVDC connections. One wrong move and you're grabbing them and never letting go. At least boots from 240 are forgiving most of the time.

For a tidy package these guys offer the chassis, connections and BMS which is victron compatible: just add LiFePo4 cells!

https://www.basengreen.com/

 

Hey so um Aliexpress is now selling a huge variety of pre packaged cells, usually around 48V up to some pretty high capacities. For example, 48v 45kWh for $6500 (plus a couple grand shipping)?? That's insane capacity and includes a BMS. There must be a catch....... right?

 

the bottom has fallen out of the Lithium market.
"The lithium carbonate CIF Asia price also fell by 9.8% in August, reaching $11,000 per metric ton, the lowest level since April 2021. At these price levels, many lithium producers are likely to reduce their output, as it becomes economically unviable to continue production.27 Aug 2024"

 

Just flicked them a web contact email where I berated them on a simple typo and whether I should spend $$ with them...

 

I would be happy to go with 2 PW3 now if I could.

 

The catch is, if they send you a box of dog poo you have zero recourse. I can say this with 100% confidence, having been ripped off by AliExpress & lodging refund requests with them, paypal & my bank.
You'd have rocks in your head to send them $8k & hope you get what you ordered.