All things Solar (merged threads)

[Franco Cozzo]

Originally Posted by nstg8a

I love this thread, I'm slowly drawing up plans for my shed, which I'm planning on being totally solar/battery powered.
It will have aircon but given it won't be used all the time, or even the shed used every day I'm hoping il get away with a lower amount of battery storage for the time being.

Refrigerative AC uses massive amounts of power, you'd be hitting the batteries very hard.

[buggerlugs]

Originally Posted by LG17

Haha - I probably pay less for diesel that you do.
If I have to go to Caboolture, Brisbane or Toowoomba I always fill up either in Blackbutt or Colinton, it's usually about 6c (at least) cheaper than those places.

I think it's an expensive way to be off the grid as well. I certainly wouldn't be following suit. At least I have 20 panels and a compatible inverter for starters.

Amazing isn't it, Colinton BP, all by itself, cheaper than the big joints. How many KW's has the neighbour got with his 8 panels ? Big family or just by himself ?
Interesting that battery info Damo............

[poppa smurf]

Originally Posted by Big Damo

Refrigerative AC uses massive amounts of power, you'd be hitting the batteries very hard.

the duty cycle of wet cells is actually very low, given the draw of a few days from a standard modern house the battery would very quickly die from overdraw.

we tried submarine batteries here, well a few K's down the track, they went very well but are starting to fail now.

also the area needed to reliably power a modern home is very large, add gas extraction, generator backup, solar panel and inverter size and it is currently very prohibitive to "stand alone" unless the house is a long way off grid.......then it becomes more attractive.

however technology advances are racing toward us.

[Franco Cozzo]

Originally Posted by poppa smurf

the duty cycle of wet cells is actually very low, given the draw of a few days from a standard modern house the battery would very quickly die from overdraw.

we tried submarine batteries here, well a few K's down the track, they went very well but are starting to fail now.

also the area needed to reliably power a modern home is very large, add gas extraction, generator backup, solar panel and inverter size and it is currently very prohibitive to "stand alone" unless the house is a long way off grid.......then it becomes more attractive.

however technology advances are racing toward us.

Your wall mount AC type unit is usually on a 15A 240V circuit, you're talking around 3600W of power there.

Take into account inverter efficiency, say 80% efficient, so 3600w / 0.8 = 4500W.

4500W from 12V is 375A

Imagine having four starter motors on your car and holding the key in turning them all over for how long you run the AC.

I'd imagine you would use a few banks of 12V batteries in a series - parallel setup, so a few strings of 48V banks to reduce your loads, at 48V its still 93A though.

Keeping in mind you want to have a 50% depth of discharge on your batteries so they live a long life, so you can only realistically use 50% of their capacity - 2x as many batteries for how much battery capacity you require.

[nstg8a]

What would be the most efficient type of ac to use?

[poppa smurf]

Originally Posted by Big Damo

Your wall mount AC type unit is usually on a 15A 240V circuit, you're talking around 3600W of power there.

Take into account inverter efficiency, say 80% efficient, so 3600w / 0.8 = 4500W.

4500W from 12V is 375A

Imagine having four starter motors on your car and holding the key in turning them all over for how long you run the AC.

I'd imagine you would use a few banks of 12V batteries in a series - parallel setup, so a few strings of 48V banks to reduce your loads, at 48V its still 93A though.

household air con is ducted reverse cycle, pulling a max 10 kilowatt (variable).....so to run that needs a power station all to itself.

ATM stand alone, at our house is not really viable without generator backup.

hoping the graphite mine over by Port Lincoln was a goer, graphite battery technology amazes me and would make stand alone viable.........

[Franco Cozzo]

Originally Posted by nstg8a

What would be the most efficient type of ac to use?

To increase efficiency you could use a refrigerative unit that can be used with hydrocarbon refrigerants (Hychill) instead of synthetic refrigerants, as they cool better and are compressed easier making it use less juice but there may be warranty implications and installers wary about using them due to them being flammable.

Evaporative cooling sucks and its not good in humid climates either.

[poppa smurf]

Originally Posted by nstg8a

What would be the most efficient type of ac to use?

smart inverter type seems to be the way to go......much lighter on power

[olfella]

Does anyone know if any work has been done on methane gas powered generators for backup units? I remember years ago there was some farmers getting most of there power using these by processing pig poo. So it was a win win. Surely technology has advanced some more in that area and could replace fossil fuel?

[LG17]

Originally Posted by buggerlugs

Amazing isn't it, Colinton BP, all by itself, cheaper than the big joints. How many KW's has the neighbour got with his 8 panels ? Big family or just by himself ?
Interesting that battery info Damo............

Him and his missus but he's doing up an old Bedford truck and she builds verandahs etc using power tools.

[CJR09]

Originally Posted by Big Damo

Normal lead acid starting automotive battery that a truck has isn't a good battery to use in this type of situation, they're not made for it they're made for a massive hit turning over an engine, then being charged while running.

Deep cycle lead acid or AGM or Gel would be the go to for a solar setup using normal battery technology, but if you want them to last you have to be careful about how far down you let them go before they are charged up, 50% depth of discharge is best for long battery life for a deep cycle, you can go lower but then it won't last as long.

Lithium has its own challenges but you can discharge them down further and bring them back up quicker without negative effects, but they are dangerous if not looked after correctly.

I wouldnt want to be discharging to 50% - you will shorten battery life by close to 60% discharging that far - when designing setups the engineers I used for system design targeted 10-20% DoD

In broad terms a 10kW lead acid battery rig with a 80% DoD over its life cycle will last all of 2-3 yrs and return approx 65 cents/kW life cycle cost

50% DoD pushes it out to 7-8yrs and a return of approx 30 cents/kw life cycle cost

20% DoD is out to 18-20yrs and a return of approx 25 cents/kw

of course the drawback to shortening up the DoD is the usable ave kWh/week drops off as well - obviously to compensate for this a larger batt bank needs to be installed at a greater $$ outlay

[Yellow_Festiva]

Originally Posted by Yellow_Festiva

I registered my details then called them to get specs and they couldn't tell me anything at all.

I just need to sit back and wait for the phone call....

Didn't get a call, but did get an email today asking me to do a survey.

Filled it out and someone will get back to me.

Hopefully......

[roKWiz]

Originally Posted by buggerlugs

How many do you use for your system ? What size ? Where do you reside ( roughly) Do you have/need back up generator ?

Sorry buggerlugs, didn't see your question.
I have 5 X 200amp/h "truck and farm" per bank, use 6 64w unisolar panels per bank with a back up Rutlands windgenerator for my cabin in North East Victoria. Bio diesel genset for workshop.
On board the yacht is 3 X 200amp/h "truck and farm" (sealed Lead Acids)batteries 3 64w unisolar panels and a air 403 400amp/h (15 knots) windgenerator.
Motorhome is all 12v powered only, 2 X 200amp/h "Truck and Farm" with 2 64w unisolar panels.

I do use a 7KVA Diesel generator for my workshop but all my trucks and boat run on B80 (summer) B50 (winter) biofuel I mix myself. Just one fuel runs everything.

Recently Century "truck and Farm' batteries have been renamed to "Heavy Equipement"

Biggest disadvantage is they are big at 500mm L X 270mm H X 250mm W ea. They are exactly the same construction as double the price so called Lead acid "Deep cycle". 11 plate wide separated plate construction doesn't allow sulphation.

Nothing goes below 50% discharge and everything is running on 12V. with no inverters as they are battery killers.

Hope this helps.

[zilo]

Blip blip

[Myluckyday]

My little solar story from SE QLD goes something like this ...

Based in the Sunshine State, I was attracted by the (then) 42c rebate available, but I wasn't sure exactly how it worked. I thought that you just got paid the rebate for the surplus electricity generated and feed into the grid ... I was wrong.

I opted for the basic 1.5kw system with 8 190 Watt panels and one of those crappy Chinese Inverters. (If only I chose a 5kw inverter and the minimum number of panels, say 1.5 kw)

Chose Origin, just in-case something went wrong and needed a warranty fix.

Paid something like $3,000 ATT

The inverter was replaced twice under warranty ... took a bit of sweet talking with Origin, but they consented. The first replacement was the same crappy Chinese Brand, the second time, a better quality one.

I asked to upgrade to a larger convertor but the reply was that, 'Sorry Ghostrider, the pattern was full'.


Read a bit about adding more panels and how to do it.

Rang a local guy and discussed what I had and what was possible.


Gumtree is full of folks selling older, lower wattage panels, just like mine, for a fraction of their original cost.

I was lucky to score 6 more compatible panels with rails and clips for 5 or 6 hundred bucks.


Had the local installer come and install for about $500, so, for about a grand I was able to almost double my output.


From the original 8 panels on the north-west facing roof, we moved one over to the north-east facing roof and now have 7 a side.


The morning generation has markedly increased. From 10ish to 2 ish the inverter 'clips' out and shows the maximum 1514 watts output.
The unit doesn't appear to overheat.
The heat-sink is warm, but not hot to touch, just as it should be.


As a family, we spend, sometimes, 1/2 our time overseas and it was a joy to come back to a 'bill' in credit for $120.

We are light on electric usage and I don't know yet if we are generating, through the 1.5 inverter, what we consume.


Since the last bill, we've been back in OZ for the 3 months (quarterly billing) so I will be curious to see if we generate more or less then we use.

Or, at worse, the money is still in credit.

Will report back once we have the next bill and thus the usage.

[davenl5l]

Just received my new plan from agl ..feed in dropping from .24c to .2280 not happy time to ring around .anybody in sa getting a better deal ?

[buggerlugs]

Mine has gone from 11 kwh this time last year to 16.48kwh this year. Not happy Jan. That is a 45.84% increase in 12 months and we haven't changed a thing. Getting solar checked out.....

[stevejg33]

Just received a letter from Energyaustralia, they're putting up my solar feed in tariff.
It was originally 9.6 cents per kw hour plus the government co payment, then it went down to 6.8 cents, now they're putting it back up to 8.2 cents per kw hour, plus the 44 cents from the SA gov, my feed in tariff is back up to 50.8 cents per kw hour.

[LG17]

Originally Posted by stevejg33

Just received a letter from Energyaustralia, they're putting up my solar feed in tariff.
It was originally 9.6 cents per kw hour plus the government co payment, then it went down to 6.8 cents, now they're putting it back up to 8.2 cents per kw hour, plus the 44 cents from the SA gov, my feed in tariff is back up to 50.8 cents per kw hour.

You shouldn't be allowed to post stuff like that! Us poor northerners are stuck on just over 6c! :(

[stevejg33]

Sorry dude, I did buy solar when the tariffs were high, but the systems were also overpriced, I paid $22k for my 6kw system back in 2011, the same system now would be probably $8-10k.
So it's swings & roundabouts, cheaper systems, low feed ins, early on, the systems were lots dearer but the feed ins were higher.
And we get the 44 cents from the gov until either 2026 or 2028 (can't remember which).
But I have to say it's the best money I ever spent, haven't had a power bill in 5 years & $3k in credit. I think it's produced around 43,000 kw hours in 5 years.

[BENT_8]

Originally Posted by stevejg33

Just received a letter from Energyaustralia, they're putting up my solar feed in tariff.
It was originally 9.6 cents per kw hour plus the government co payment, then it went down to 6.8 cents, now they're putting it back up to 8.2 cents per kw hour, plus the 44 cents from the SA gov, my feed in tariff is back up to 50.8 cents per kw hour.

Awesome, that explains why my power went up 33% qtr this time, not your fault obviously.

[drz250]

I'm saving for equipment for the property I own in SA's far north. The plan is to be self-sufficient on electricity by using both solar and wind power.

I will be using wood for heating and some cooking but mainly relying on solar electricity for refrigeration, cooling, water pumps, hot water, etc. I currently have a 4kw system but want to expand in the future - firstly I'll be upgrading the battery bank.

[deesun]

Has anyone priced up either Tesla or Instyle Solar's powerwall batteries yet? Approx what price do you think they will be here in AU?

[xisled]

Originally Posted by deesun

Has anyone priced up either Tesla or Instyle Solar's powerwall batteries yet? Approx what price do you think they will be here in AU?

Last I heard about pricing me this was a few months ago, your looking around $12000 for the system but you needed a minimum 6kw system so you need to add extra costs to upgrade the system it self.

[deesun]

Originally Posted by xisled

Last I heard about pricing me this was a few months ago, your looking around $12000 for the system but you needed a minimum 6kw system so you need to add extra costs to upgrade the system it self.

Well I have the system, just need the 12k.

[poppa smurf]

and up go the power prices yet again......I wonder how many more poor buggers will lose their power with this round of increases.

[wodahs]

yep and they wonder why were interested in solar to help keep our costs down then they rort us on the feed in tariffs

wonder how the battery storage prices are going these days am always thinking getting completely out of the control of the power suppliers

[Franco Cozzo]

Originally Posted by wodahs

yep and they wonder why were interested in solar to help keep our costs down then they rort us on the feed in tariffs

wonder how the battery storage prices are going these days am always thinking getting completely out of the control of the power suppliers

When it comes time for me to fly the koop and have my own place I'll be looking into this.

[poppa smurf]

storage technologies are limping along but Govco aren't making it easy for any "innovations".......disincentives rule funny how the power moguls can control an entire nation like this.

meanwhile more folks are turning their heaters off on freezing cold nights, too frightened of the power bill.

[LG17]

My 5kw system is just over 2 years old now.
Our power bills used to be $650+ every 3 months, summer or winter.
They are now $240-$250, even with the crappy feed in.
Over the next 12 months I intend to keep a close look on consumption to see if it's feasible economically to go off the grid.
As far as winter heating goes, it's all taken care of with the chainsaw.