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Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578
Posted: 11:35pm 23 Oct 2019
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You are a much more charitable man than I with your assessment. They keep moving the goal posts to protect their profits which last year were $2.7 BILLION for the industry. That's a lot more than just staying in business.
Which is why I have no problem with not playing the game with those whom seek to have it all their own way. The fact they take the power one person generates and give them .6C for it and then sell it to the next door neighbour for .30 c or more is a rip off. What really sh*ts me to tears is they then have the audacity and insult ones Intelligence by preaching the greenwashing and trying to tell us that building solar and wind farms is good for the environment and they are so environmentally conscious. I'll stop there before I get too fired up about that.
There is also the problem of power blackouts.
And I think that's going to be a BIG problem this summer. SA and VIC had it last summer, NSW is going to cop it this year as well. I'm setting up a currently disused part of my my shed roof that has panels not connected to an inverter and some batteries so I can run the fridges at least.
I'm also trying to get hold of a 10KW Gen head to hook up to one of my ( many) diesel engines so I'm 90% covered. If the gen head is 3 phase I'll be laughing, if it's single I'll be hot because the AC is 3 Phase but I am thinking of putting in a single phase split as well.
So all things considered, a grid tie may not produce the long term financial benefits many people hoped for originally, as the buggers keep changing the rules. Grid tie may still be worth looking into as part of a much broader overall plan, but its not really some kind of ultimate solution for either us or the power utilities.
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 12:14am 24 Oct 2019
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All this talk about thousand dollar plus power bills just freaks me out.
I always try to use a little grid power just to stay connected. My lowest bill this year was $39.35 for the quarter.
Cheers, Tony.
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 12:31am 24 Oct 2019
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We're looking at putting in a second battery charger/grid hybrid inverter here- basically disconnecting the panels from the existing one and connecting them to the hybrid
Our gridtie has pretty much paid itself off already (next bill or two and it will have, however they are talking about cutting our payment level in half, which will make the batteries look more attractive...
I did some number crunching and as we only use 7kwhrs a day (solar HWS, 2 people living here) even with the electric stove (we don't use it much though- most of our cooking is microwave, one of those 'air grillers' or the old crockpot)
If we use 160ahr batts from Trev, running at 48v, the total battery cost is only $4700- only 700 more than we actually paid for the solar install- and it paid itself off in 3 1/2 years At those discharge levels, we would get 20 years plus out of the batteries, and with the elec bill still practically zero, even at the reduced rate, we would be looking at a 4 year payback, after that power for free again...
Plus of course not reliant on the grid (we would rarely pull power from it at all, maybe if we got 4 or 5 days of heavy overcast) The hybrid would be set up to charge the batts first, then excess goes back to the (official) gridtie inverter
Same at night, it would pull power from the battery bank first, and only if it is too low, will power be pulled from the grid
Officially it will still be the same system, the only difference will be the unofficial hybrid inverter in the chain Of course our consumption is far lower than Davo's which makes it far more practical, we don't have heating costs (as we don't even have a heater lol- we fitted roof and wall insulation and retractable sunshades over the windows and simply don't need it here) or a pool (would love one, but simply not a big enough block of land to put more than a kiddies wading pool in it lol) So for us, I can see it being worthwhile, others maybe not It depends on so many factors...
ETA BWWAAHH Beat ya Warpspeed...
Edited 2019-10-24 10:38 by Boppa
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 12:43am 24 Oct 2019
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That is the problem, the goal posts keep moving.
They will cut it by half, then in a few years halve it again. They absolutely hate paying out cash, and from a business perspective its just not viable.Cheers, Tony.
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 01:11am 24 Oct 2019
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Problem is that they have made it so expensive to have the electricity on, that battery systems (especially with the price of lithiums being so low) that for many, hybrids are looking better and better... if they cut me back down to 10c a kwhr, that reduces the battery payback time from 8 years (just barely worth the bother) to 4 years... And should it become apparent (which I think it will) that we are barely using the grid at all, should the connection fee rise, it would be iffy if it stays on at all... Enough people start to look at it that way, and they are losing customers- ie less profits...
Another factor is that if solar hadn't taken off the way it has, by now they would have had to build at least another 4 power stations in Qld- and those don't come cheap... (I'll have to see if I could find it again, was in one of the solar mags, the energy figures for Qld with and without solar, the electricity companies would have had to spend a minimum of $20 billion in new plant, which would have cut their profits quite a bit...
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578
Posted: 04:00am 24 Oct 2019
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Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 05:56am 24 Oct 2019
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One plug pack is sure not going to make much difference.
But when you do an energy audit, you will discover many things that run continuously, some appliances even when they are switched off can suck five to twenty watts of totally useless standby power continuously 24 hours.
Plug packs are the most obvious thing, but many things switch AFTER the internal transformer. "Smart appliances" with time clocks or hand held remote controls for example are continuously powered even when off so that the "clock" or "radio receiver" is continuously powered up.
If you find twenty things around the house, workshop, and garage, that each draws ten watts when off, that is 200 watts ! Over 24 hours that is 4.8 Kwh. And it could easily DOUBLE YOUR daily power consumption figure. What about your garden watering system, or your garage door opener ? You will never know until you do a power audit.
Its not all as trivial as many people think. Oh golly a microwave oven draws 2.4Kw for maybe a minute, which is only 40 watt hours, not all that much. Probably less than something else that is actually off !!
For instance, an F&P washing machine uses about 85 watt hours to do one full load at full high spin dry speed. Max peak power is during initial spin dry acceleration, about 340 watts peak if I remember. That is actually all pretty good.
What is more surprising is that it uses the same 85 watt hours over a 24 hour period when switched off. So just leaving it plugged in all the time uses as much power as doing a full flat out washing load every day. Its easy to remember to switch it off at the power point.Cheers, Tony.
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 804
Posted: 11:03am 24 Oct 2019
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So you weren't happy with the overall result?
SA seems to have a bad reputation for some reason ... but where we are ... we don't have too much trouble. It's a couple years since we had that big one ... about 8 hours without for us ... and one of about 3 hours last year. There was a short one this year too I recall ... about half an hour. If it never gets any worse we've got nothing to complain about. Cheers, Roger
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 804
Posted: 11:46am 24 Oct 2019
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I think I probably need to have some sort of grid connected system to get some return from excess solar.
I'm not into openly flouting the system, so I reckon I'd be able to call on a local sparkie to do the stuff that's out of my league.
I'm quietly confident of a much better price on a forklift battery. My friend has contacts with companies that lease forklifts ... and they often pull out perfectly good batteries to fit new ones at the start of a new lease of a s/h machine.
In speaking with him today, he has done exactly this with his home ... fitted a battery along with a hybrid inverter etc.
He did mention that solar people talk amphours per 20 hour period ... whereas they (forklift people) talk per 5 hour period ... so I realise I need to compare apples with apples.
Yes, it certainly seems that way. Maybe I need to contract someone to collect some for me and then come for a drive with my trailer.
Ah, I'm sure I'll be able to blow stuff up as well as the next guy ... but electronics is my field ... repairing cct boards ... smd, micros and that sort of stuff ... 45 years or so.
I've got several dud Aerosharp 3kW inverters lined up ... $25 each ... am picking them up in the morning from an "inverter graveyard" in Adelaide. Anyone looking for anything in particular, I can ask for you there?
I hear you on the "pain" aspect ... I've wound enough coils to know my thumbs are feeling a bit edgy already just talking about it.
I've never attempted a toroid though, so that will be something new.
I'm a bit of a cheapskate, so hopefully it won't get that high.
Cheers, RogerCheers, Roger
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 804
Posted: 02:03pm 24 Oct 2019
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Certainly cheaper than the existing lower end ones ... Sungrow and SolaX. Wonder how reliable they are going to be (or not) ... and whether you'd ever get any backup if you had problems.
Have you decided what type you might get? One of these Socolor?
Wow, would be nice if ours was that low. Cheers, Roger
Warpspeed Guru Joined: 09/08/2007 Location: AustraliaPosts: 4406
Posted: 05:31pm 24 Oct 2019
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I was very happy with the overall result, but not with the electronics I was using.
At that stage I had eight panel series strings producing around 240v dc, that went into three 2Kw switching power supplies that generated +225 and -225v voltage regulated dc, and that went into a very early version Warpverter.
This early Warpverter used no "large" toroid, just medium and small and had only 27 steps. It also had no internal voltage regulation, which is why the two incoming dc supplies powering it had to be voltage regulated.
I then had some further ideas about how I could add voltage regulation by having multiple lookup tables instead of just one lookup table, and I also decided to add a fourth inverter to get 81 total steps and a much cleaner ac waveform. The next logical step beyond that was to make provision for a future battery.
So the new 5Kw inverter was built as the "final" ultimate Warpverter. This has four transformers, voltage regulation, and is designed for an input voltage range of 90v to 180v dc. I reconfigured all my solar for series strings of four panels, instead of eight, and it ran like that for a short while, again with a three phase dc rectifier powering the system at night.
Functionally it was the same as the original system, but with totally new and improved electronics.
The last update was fitting a 100v Lithium battery so I could be completely independent of the grid. The rectifier is still there but never used except during really bad patches in mid winter.
That kicks in and out automatically if the battery voltage ever gets very low. That is the system I now have, and am completely happy with it.Cheers, Tony.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 11:04pm 24 Oct 2019
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Roger, sounds like you have a good grasp of it. Big shed roof to mount panels. Electronics experience. Access to cheap fork battery. Access to cheap torroids.
Yep in that case I would say go for it.
If you can get the aerosharps for $25 each, certainly get 4 or more of them, trust me you'll kick yourself down the track if you don't. Edited 2019-10-25 09:04 by renewableMarkCheers Caveman Mark Off grid eastern Melb
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578
Posted: 12:00am 25 Oct 2019
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I was looking at some of the fleabay type sites this morning. I haven't bought any panels for a few months already having well more than I can use.
I see the asking prices have dropped substantially with some good deals going. Inverters are still usually stupidly overpriced but the panels have come down a lot. I think my $100Kw bench mark needs some serious revision. From what I saw this morning I reckon I could halve that without thinking.
The other thing I notice is rather than the typical 8-12 panels being offered, there are a few people, probably installers offering in decent qtys. I was buying 5Kw at a time, 6 Kw on the last lot and it makes things a little easier to set up. That said, I have set up mis matched arrays on the same inverter and they don't care and also mis matched panels. That may pull the array down to the lowest rated panel output but so what? If they are left over orphan panels and you string them together and are pulling 2 Kw out the things, that's still 2 KW.
That is something to be aware of and verify when purchasing. BIG difference in the C5 and c20 rates.
I think forklift packs leave commercial batteries for dead. 13 KWH Power wall is $15K. 35+ Kw hour forklift pack, $3-4K. AND.... when the forklift pack is dead, it's still worth good money as scrap. When the power wall is dead, I can well see there being a charge to dispose of them in the future. Sure you might only want to run the LA pack down to half cpapcity but they are meant to go lower so the occasional deeper discharge isn't going to hurt. Even if it did, with any decent care it's not logical to think a Lithium battery is going to outlast 3 LA packs.
The forklift packs are Big Bulky and heavy. Not like you need to move them around in a home installation. The power walls might be great for those that have too many dollars and not enough sense that want something completely hands off but for those with a bit better skill set, there isn't that much to LA batteries especially if you put in an automatic watering system.
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 12:31am 25 Oct 2019
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C5 means it's flat in 5 hours (very heavy load) C20 means it's flat in 20 hours
So if they say it's a 600Ah battery @ C5 rate, then it's much more capacity at the C20 rate
If you can get a 800Ah @48v battery that would be a nice size for an average home.
BUT it entirely depends on your usage profile, how much you use overnight is important as that's when you will be relying on the battery.
It's also going to depend on the condition of the second hand battery, 800ah on the label doesn't mean it will still be 800ah.
Watering is piss easy I spend maybe 2 min every 3-4 weeks to top mine up and give the top a wipe down.Cheers Caveman Mark Off grid eastern Melb
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 804
Posted: 03:04am 25 Oct 2019
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Very cool Tony.
So ignoring the battery side of it for a moment ... what are the advantages of your system over say the OZinverter?
I've read hundreds and hundreds of pages from several forums over the last week ... is there a specific thread about the build and the process?
Thanks, RogerCheers, Roger
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 804
Posted: 03:21am 25 Oct 2019
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Haha ... thanks for the vote of confidence Mark.
For a while there I thought everyone was going to try and talk me out of it ... and that it was hardly worth the effort.
I've just got back from Adelaide (I remember now why I live in the country) ... but they did have 4 there ... so I grabbed all 4.
Need a cup of tea and a lie down now ... I know everyone says they're heavy ... I believe them now.
I have a feeling he was only talking 500Ahr @ C5 ... but suggesting $600. Maybe I can up my specs or get two.
When you suggested an 800Ah @48v battery would be a nice size ... that's at C5 or C20 (this bits all new to me)
Pleased to hear watering is no issue ... I thought the auto watering kits out there were particularly expensive.
Cheers, RogerCheers, Roger
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 804
Posted: 03:37am 25 Oct 2019
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I need to ring around the local solar installers and develop a relationship. Maybe I can do a deal of some sort.
There's no question the forklift batteries are going to be bigger, heavier, perhaps messier ... but I've got plenty of room (big sheds) ... and once I've decided on a location ... they're going to be there for the duration ... and most importantly, the price is right.
Thanks for all the support and encouragement guys, I really appreciate it.
Cheers, RogerCheers, Roger
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 03:46am 25 Oct 2019
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if he has 500ah @C5 for that price yeah you could grab 2 and put them in parallel. BUT you would need two that were matched very well. That is something you won't really be able to tell till you put a few charge discharge cycles on them. If you can get something 600-800ah @C5 that would be great.
But if not pick up a couple of the 500ah if they don't match get another one till you find a set that match well.
At that price you'll have no trouble offloading the ones you don't want.
Now that you have stated you can get batteries at that price I'm suspecting you'll get pestered for batteries hahaha LOL. Your inbox is going to be full.
Also try to get ones that bolt the connections together, some are soldered and are a pain if one cell goes poop.
Hell..... 2x500ah for 1200. oh boy that's a steal.
Tempted to pester you for some myself, not much room here though.Cheers Caveman Mark Off grid eastern Melb
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 804
Posted: 04:25am 25 Oct 2019
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Haha ... I'm certainly happy to ask him. Maybe I'll be able to do a trade for some cheaper panels. Load up the trailer and come for a drive ... meet half way somewhere.
I can see a bigger unit would be easier to manage than 2 smaller ones ... but should still be do-able.
Thanks for the heads up on bolted connections ... can see the advantages there.Cheers, Roger
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578
Posted: 09:08am 25 Oct 2019
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100AH @ 12v IS OVER 1kWH. 800AH@ 48v IS 32 kWH. Even if you only run the pack to 50%, that's a LOT of power for a home over night.
While things may be a bit backwards in this specific case, Normally panels are a Lot cheaper than batteries. I think they would for about 99% of people. Myself, I would repy less on the batteries and more on the charging. If you throw a good amount of panels at charging a battery, you will have no problems summer or winter. For the really crappy days, generally cheaper to use a generator than have some over size battery banks.
Absolutely. The thing to remember is that you have to have the charging capacity to replenish the usage regardless of the battery size. You also want to over rate it enough to deal with Winter at very least when the usage might be more. Whether you are taking 20% out of the pack or 50%, still has to be made up or you will run out of power.
I would tend to go lighter on the battery size and heavier on the charging. That way the battery is charged up quicker or as quick as it can be and you have reserve capacity for the less than great days.
That's one thing if you take 100Ah @12 V to be 1 KWH. it's more but it always pays to hedge your calculations so at worst they are right and if they are wrong you are in Front :0).
Notice. New forum software under development. It's going to miss a few functions and look a bit ugly for a while, but I'm working on it full time now as the old forum was too unstable. Couple days, all good. If you notice any issues, please contact me.
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