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wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 01:40pm 18 Jun 2022
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Recently our energy provider made some changes to our energy plan and shifted us from fixed rates to a time of day usage. Would you believe we are not better off, our low rate is now between 1:00am and 6:00am and between 10am until 3.00pm. Our peak rates are now higher than before and cover most of the period we are not generating feed in.
They can tell you this two weeks before the bill for the current period is due to arrive and also backdate it to the beginning of the current billing period. This is (according to them) not a change to our contract apparently because it is buried in the fine print somewhere that we agreed to them being able to make such changes.
In my view this is a "sharp practice" bordering on theft. One should have a right to tell the supplier where to shove their wonderful new method of reaming their customers but of course there was no fore warning.
If I was the supplier, I would send the notice out two weeks before the end of the current billing period and inform the customer of the proposed plan changes and give them an opportunity to accept or go to a different supplier. Further, the feed in tariffs are also changing from fixed 12c /kWH to 12c for the first 300kWH and then 5c after that. In summer we produce ~ 85kWH per day so what do we do now after day 4 ?
A young engineer at work came up with an interesting plan after also being reamed by his supplier. After telling them where they could put the new rates he swapped to a new supplier whose reamer was more modest and set about a revenge plan.
He bought batteries, an Eltek charger, found an older 2kW transformer style inverter that would operate from as low as 48V. He fitted a current clamp to the active feed wire in his switchboard and got a small wifi unit running from a spare 12V supply in his Fronius inverter and wrote some software.
Then he set about feeding energy from this setup into a power point until the export reduced to zero from the instantaneous current information from his wifi gadget. So now if the sun goes behind a cloud for 10 minutes instead of drawing from the street at peak cost he pays nothing as the batteries supply the shortfall. He charges his batteries via the Eltek when he has excess solar power before feeding anything back to the grid. At night time as the solar stops the battery and grid oops house feed inverter take over ensuring that the house draws nothing from the mains until the batteries are exhausted (he has just bought more batteries) and the inverter goes off line and some costs then ensue but the lights etc stay on and no switching involved.
It sounds like a great product idea that anyone with solar panels could use to their benefit. The only real negative is having to find an ever decreasing source of low voltage input inverters that are already as rare as the proverbial.
So for those of us that are not off grid and could make use of this I reckon that with our current inverter the mains needs to be used as a reference signal to create our sinewave (self commutated) so if the mains goes down the inverter stops. Then we need to control the current feeding back into the mains so the export is held at zero. There could be an option that after we switch off the street supply we can operate a switch on the inverter and generate our own 50Hz commutation signal and continue to run the inverter / house until the mains returns.
Apparently if the batteries are housed in something with wheels on it this is not against the regulations. (I am unsure if the rules say the wheels must be able to turn.....). Because it plugs in via a 3 pin plug all the complex fixed wiring rules and regs are avoided and it also complies with a requirement that if the mains stops so does the inverter.
He is not interested in taking it further but I wonder is there a market need/opportunity here? Edited 2022-06-18 23:43 by wiseguyIf at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
Haxby Guru Joined: 07/07/2008 Location: AustraliaPosts: 423
Posted: 01:05am 19 Jun 2022
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Warpspeed had a similar but different setup that was quite ingenious in its simplicity.
I believe he used a transformer and rectifier to rectify the grid down to around 130vDC.
His solar panels were a higher voltage, say 150v minimum.
He then diode coupled the two supplies to feed his inverter.
The above solution is really a good mix of all of the variables. Nice and simple = reliable.
When the solar stops producing, the grid takes over seamlessly. No glitches, no mechanical parts.
Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458
Posted: 06:29am 19 Jun 2022
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No problem with my energy supplier. It was set up a few billion years ago. We did have grid power when we bought our mountain paradise but the service was unreliable ( in wind and rain it failed) and the powerlines were ugly. So we got the supply authority to abolish us. Never been abolished before but it felt good. I have had grid power for a total of 2 years now in the last 40 years, so good riddance to them. 4 years totally running of that big nuclear furnace in the sky and loving it.
Pete
rogerdw Guru Joined: 22/10/2019 Location: AustraliaPosts: 852
Posted: 08:00am 19 Jun 2022
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Not hard to believe at all unfortunately, in fact it's exactly what I'd expect nowadays.
Agreed, it certainly is shifty and typical of big business and their disdain for all us plebs.
We're with Origin Mike, who are you with?
Annoyance and irritation can be a great motivator, pleased to see how he's approached this.
That's particularly interesting. Any idea if he can point us to those regs please ... it may make it worthwhile to peruse them before I make my final build. Just need some casters for a ton of batteries ... mmm!!!
I'm sure there'd be people interested but with govt and power company crooks constantly changing the goal posts it may be difficult to impliment. Certainly worth thinking about though, especially being able to potentially sidestep a lot of rules and regs by being plug-inCheers, Roger
Revlac Guru Joined: 31/12/2016 Location: AustraliaPosts: 1024
Posted: 08:32am 19 Jun 2022
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Its a good way to have some backup during power outages without too much extra expense, depending on how far one whats to go with it, also a good first step towards off grid. However it may be different in some states, In QLD we had a grid connection years ago, as the power bills kept increasing and our power usage decreased, the service to property charge was the same or higher than the power we consumed, and any feed back to the grid may not cover that cost, I don't like giving them power for nothing. The power quality was not good, blew up all sorts of stuff, the compact fluro's use to have a very short life, blow one up put another one in turn it on blow it up and it takes out the light in another room at the same time. Turned the power off completely and we still get charged for not using it, so ended up getting it abolished. No more power problems or blowups, been using the same lights for years and not blown up any, the neighbours are still having power problems.
Been Off grid for years and love it. Thing is that there is no going back to the grid with this option, to get power back it will be treated the same as a new house build.
Be careful if you decide to read the Regs, It will likely make you sick all over your computer, or worse, give you some more mental stress.
I think there is another change in the mix, looks like they might want solar with battery backup on every house later on, to supply the grids (so called) short fall in the afternoon, if or when that happens it will be unlikely that the power on your side of the power meter will be yours, under your control. Edited 2022-06-19 18:37 by RevlacCheers Aaron Off The Grid
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 10:22am 19 Jun 2022
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Thanks for the comments Phil. If my inverter was intended to run the house totally the dc option would be a good solution.
There are a few issues though. We have a pretty large house and my good wife insisted that our air conditioner must be able to make every room comfortable simultaneously if required, and it does do that in spades. We installed the largest single phase inverter that Actron make - its maximum draw is 30.9A (ouch) in a very short time you are very comfortable but at a cost. Then there is the double oven and the induction hotplates all guzzlers - sorry to go on but you get the picture. (Dr Phil?)
In light of this we installed 13.5kW of solar and a 10kW Fronius inverter, I intended to stay cool in summer and didn't want the ongoing bills associated with all the hardware. The solar guys told us to get with AGL who initially were paying us 20c/kWH and to date we have not paid a cent for our power - since late 2019 (if you ignore the ~$9K solar cost) but I expect that will change this year.
So we will very often have excess power to feed back but I want to do that on my terms - once my batteries are charged and I dont have anymore heavy loads to run ie dishwasher washing machine etc I would rather be getting 8c/kWH for the excess than nothing. I need the grid to run the Actron and any feed in tariff I can manage helps offset the poles & wires daily charges.
Warps system unfortunately doesn't allow you to feed back excess energy.If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 10:26am 19 Jun 2022
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Very funny Pete, I imagine you also have fixed your rates for eternity too lol. If I had my way I would have opted for a number of a/c split units and less energy overall but I like a happy life.....(and how's that going for you.....)If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 10:35am 19 Jun 2022
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Hi Roger, we are with AGL - I think there is not a lot of differences and given the current issues there will probably be little to gain by shifting, but if there is a better deal to be had I WILL shift.
I will find out but won't see him until Wed. As I said if it is wheeled there are loopholes but maybe they can just be square ones fixed lol
Have you got your PCB's back to play with yet ?If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 10:51am 19 Jun 2022
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Aaron I also hate giving back power for almost nothing and then paying 36c/kWH to buy some back. If you google the feed in tariffs for the various suppliers it ranges from 0 cents to 12c & some of those have gotchas after a fixed amount of some miserly kWH numbers. I believe a J tariff (low rate) still exists at night time - this is fed from fossil or and wind. Why aren't all the J tariff electric re scheduled for hot water heaters etc at midday when there is so much solar feed in, the grid rises high enough such that most solar units are being throttled back.
Maybe we need to start a protest revolution and wait until there is a calm day with little wind and all solar feeders Australia wide unite and turn off their solar for the day and see if anyone notices - I'm betting they will - maybe we can secure a better deal ! It would be worth it for the few dollars we would miss out on.If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578
Posted: 11:23am 19 Jun 2022
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Have to say, I really don't care about their Biased rules and regs. In my book they are unfair, overly biased, immoral and if one had a choice or could even understand the legalese, would never agree to them. I don't respect people or organisations that don't respect me. Others may be different, that's up to them but I try not to be a victim and not interested in being noble or better than the other guy. Stuff them.
I asked my solicitor mate about something to do with this some time back and his advise was it was not illegal and although it may be not in the spirit of their contract which was all their way, he felt there was little chance of prosecution, they would simply issue a cease and desist order and if I played ignorance and the green, save the world card they would drop it because they wouldn't want adverse publicity.
For a couple of years, FIT rates have fallen through the floor. The excuse was the FIT reflected the wholesale price of power and the generation component. Not the wholesale price has been capped at $300 Mwh, I want to see with this next lot of price rises if they are going to reflect that and put the FIT back up or they are going to screw over the consumers once again and make some BS excuse for that.
These companies are lower than Slime in my book. The rates have been lower for a couple of years now than the flat rate I signed up for. Never have they sent me a letter or email saying you could be on a cheaper rate. Now I get a letter saying price of power is going up so your rate will increase. This is the sort of chit that takes away any and all respect for these mongerals or doing the right thing by them.
They don't play fair and I think people that want to do the right thing and play fair with them are rather gullible TBH. I treat people ( and entities ) as they treat me. I can game the system too. I do not steal power as that would be illegal and criminal but I can play them at their own game and have no problem whatsoever doing that.
As I said in another thread, I saw this coming a while back as did my neighbour that works for a power co. Batteries are still quite questionable in the big picture in my book but that may well change for those of us whom can set up or own systems and not pay the stupid price of commercial batteries but I think there is more to it now.
I had lunch with some friends today and they are more concerned with supply as am I. I said to the Mrs through the week about getting batteries and she seemed to think it was not a creditable idea or I was being paranoid. Hearing my friends concerns today I think made her realise the situation.
My neighbour whom is pretty high up in the power co says this isn't a 2 year things as being made out, he reckons at least 5 is more realistic and they will go for the most price rises they can so double the current rates in a few years is NOT out of the question.
Keeping the lights on at home through cost or supply is one thing. What really worries me is beyond that. No power, no food, no fuel, no services.... That's the big worry. Imagine going to the shops and half way though all the lights go out and you can't get food or the servo is closed because there is no power for the pumps and the efpos is down etc. Imagine what that is going to do to the price of EVERYTHING!
I am on an offgrid group that must have an average IQ of 50 and many of them that are not on grid power are all laughing. Least they were till I said do you smartarses realise no one is immune, this is going to affect the cost of everything so don't get too cocky, you WILL be paying for it same as everyone else.
The power industry in Oz makes over $3Bn a year PROFIT yet we get told to help the grid by turning off AC on the hottest days, heating on the coldest and to basically inconvenience ourselves to help them maintain their profits.... and the sheeple fall for it.
They have been BSing us for years there is too much solar input and too much power in the grid from rooftop systems while they build solar farms paid for by the us the people while they then get to profit from them by screwing us over some more. The whole thing of batteries on homes is to make the householder pay to prop up the system they have raped and Pillaged so they don't have to spend on infrastructure and reduce their obscene profits and multi million dollar bonuses to Directors and board members.
Clearly they are going to be desperate for power now but not one watt will they get out of me at their pathetic FIT's. When they start paying something reasonable, things might change but I'll make sure it's to MY advantage not theirs.
.
Davo99 Guru Joined: 03/06/2019 Location: AustraliaPosts: 1578
Posted: 12:49pm 19 Jun 2022
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He also put me onto an idea I use and works perfectly. Much smaller scale but none the less.
I have some lights and heaters for raising vegetables. No, not " Herbs" just tomatoes etc. He suggested tieing solar panels to a battery charger I was using for a power supply. When the panels produced higher power than the battery charger, no power would be drawn, in the middle in lower light they would share the load and then at night the charger would seamlessly take over.... and it does.
Seems to me with the house hold idea all lone would need is an inverter feeding back to the mains from batteries at a higher voltage than the mains. This would be the dominant power source and with enough solar input through the day would power the house while the batteries were in float or charging.
To stop the power going back to the grid, a zero net export device could be used which are readily available commercial units that have to be fitted in some areas ( SA for one I think) and that would mean the system was powering the home only. may be possible to export with excess solar without draining the batteries, haven't thought that far through.
If the batteries depleted then the inverter would drop out or supply a lower voltage and the grid would take over.
One thing with all this is how often things change. Couple of years back origin in my area and I think AGL were fractionally higher, were paying a couple of cents over half the buy price. In other words the purchase price from them was .30 kwh and the feedin was .16.
A large part of the year I can generate double what I use so I could have made money from that. Next time I looked power was .28C kwh but FIT was only 5 C. I told a mate whom was getting solar to go with origin and lock them into a 5 year FIT. they would only give him 3 years but he has done real well out of that last 18 Months at least.
Point is with them changing the playing field all the time it's hard to setup or know what the breakeven point is and how much and what returns you will get on an investment.
I guarantee there has already been a bun rush on commercial batteries and I bet they have already skyrocketed in price on what they were 3 months ago. The solar industry is one of the most crooked and Corrupt out there atm and not far short of the power industry which is no surprise.
Other batteries like AGM's and traction packs won't be far behind.
I think it would be wise with any system that stayed grid ties to be able to export or not, depending on what the market was at the time. That said, those zero export contraptions were not cheap as the inverters that have that feature built in are not.
Maybe the easiest way is just forget the grid all together and go it alone.
I gaurantee with the price increases and supply issues many people will leave the grid. the next thing from the power mongerels will be an increase in price because they have less customers and need to raise prices to cover costs. They have already put this one though just after solar became popular claiming declined revenue meant they had to increase prices for existing customers. For commercial customers and those that live in units etc that can't generate their own power, they have them over a barrel that's for sure.
nickskethisniks Guru Joined: 17/10/2017 Location: BelgiumPosts: 458
I own the unit for 4 years now and most of the time I usef it as a normal gti. But it makes a great battery load too.
During 1 year I used it to dump excess power on the grid. Also, my connection was not strong enough to dump +5kw on 1 phase so I spread out the energy during day and night.
Wiseguy, it sounds like a new project to me. Making a big "controleable' step up converter, preferable with galvanic isolation. So you can use your current GTI. ( Regulation and rules are another story)
I was working on something like that for my parents house, I'm still thinking about using the normal HV GTI. Charging the batteries with solar panels and then injecting battery energy in the GTI. There are several ways to setup something like this. The lesser Steps Involved the more efficient the system is. Charging could be done straight from the solar panels or charger from mains. Injecting in the inverter could be done with a boost converter or rectified from hf/lf transformer.
Godoh Guru Joined: 26/09/2020 Location: AustraliaPosts: 458
Posted: 10:24pm 19 Jun 2022
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Hi Wiseguy, I guess I am in a very different situation to most of you. My partner and I live in a small ( two room cabin) So our heating is covered by a small wood heater. We do not need airconditioning where we live. We feel the heat though when it gets above 25 degrees in summer we find it hot. We try not to go to the lowlands when the temperatures down there are ) near 30 or more. Power wise, well we have solar/electric/wood hot water. A small benchtop oven, induction cooktop. My partner and I are on the same page, we dislike having too much stuff and dislike paying for stuff we can do ourselves . So yep our lives are fantastic. I have lived my life on the fringe really, in home made houses ( most very small and cheap). I had a mortgage once, felt like a pallet of bricks tied around my neck. Glad that I moved out of that and went back to small cabin living. I did keep things cheap by not bothering with councils much either, seemed that they agreed with me, I did not bother them they forgot about me. Nice arrangement, all live happily that way. As for studying standards Standards Australia are private enterprise now, their job is to write standards and make money. The rules will keep changing, they won't be able to tell you what they actually mean and frustration is the rule. Cheers Pete
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 12:16am 20 Jun 2022
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Hmmm lots of food for thought.
Thanks Davo and Nicks and Pete for your inputs. Going back to Warp & Haxbys reminder maybe diode or-ing can be the answer by placing them in the right place. I believe the Fronius can be set to zero export.
The 10kW Fronius inverter can operate from a 200V minimum DC voltage and a maximum input current of 27A.(Max input voltage is 1KV!) I think our panels are ~ 600V ea
If I made a Dc/Dc converter with its voltage being just a tad higher than the Fronius lowest DC input - lets say 220VDC and using 2 x diodes as an or gate when solar drops below 220V the DC/DC could start and be ready to input energy as the solar drops away seamlessly.
Now with zero export setting we have a house feed inverter (instead of grid feed) commutated by the mains but receiving power from batteries but exporting nothing.
When the voltage rises above 220V as the solar comes to life we then send a command to the Fronius to deliver to the grid what ever we are not using locally. This is assuming the Fronius can have a nominal export setting that suits my needs.
Does this sound feasible to the solar experts out there? More research needed here on my part. Will the MPPT need to be disabled or is it an advantage to have it?
My inverter will not be redundant there will be times of no grid so I will throw the street & Air conditioning breakers, start my local inverter & life will be ok again. Edited 2022-06-20 10:19 by wiseguyIf at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 12:27am 20 Jun 2022
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Pete, my daughter also wants to build and live in a tiny house that she builds with her partner and powered/heated by solar (and wood) - I say that people should be able to live the way they want and to heck with what others may think. She is a true "greenie" hates plastics and meat and is a vegan to boot and grows a lot of her own produce.
I like those old jokes that I need to get into shape - well round is a shape? Eating meat is mostly vegan just eating processed grass ? Personally and to my daughters disgust I will not give up my occasional steak or sausages anytime soon.If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 12:36am 20 Jun 2022
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Nicks, I just looked up the inverter model you mentioned - I should have read it before I posted my suggestion above - it seems I have basically re-invented the wheel.....
Ok I just re-read again what you posted - I glossed over the sentence under "New project" - you were already proposing a DC/DC converter and minimal connection - I was slow to get your full meaning - so the sentence below is now irrelevant/redundant/wrong.....
I guess the main point of difference with my suggestion is using my current HV input inverter and creating the right feed in voltage to suit & utilising the inverter that I already have with minimal wiring changes.
I think if I plan to diode OR the two feeds together I might also use a contactor that keeps my feed-in totally isolated until the voltage drops to less than 250VDC those high solar voltages and currents are very dangerous/lethal & cannot be underestimated. Edited 2022-06-20 11:31 by wiseguyIf at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
Clockmanfr Guru Joined: 23/10/2015 Location: FrancePosts: 429
Posted: 09:00am 20 Jun 2022
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Hi Guys, Stay with me on this, its roughed out here below, its one of my stories. I need to write it for a book publication.
The Philosophy of going Green and Sustainability.
Even here in France the self-consume electric has arrived big time.
Yes, the French government even have laws that allow individual properties to make and consume as much electricity as they want. And even use the grid as virtual batteries without injection. BUT you are not allowed to sell it to anyone, except 3KW max to the Governments EDF utilities.
However, there is a big crunch happening here, with just absolutely no 'non-commercial independent' information.
The so called RE retailers/wholesalers here in France don’t really know what they are doing.
AS we have been doing what we are doing for over 20 years now, as you can imagine i keep a low profile in our local area. At first the locals thought us ‘mad’ with solar trackers, PV and Wind Turbines, now, even they have come around. Here in our locality i have tried to help self-installers and self-consumers and the going green folk who want OFF GRID, and have asked us for our independent advice. However, its become a nightmare.
Why is it a nightmare, well most of Europe and especially France is mostly Urbanised and folk here have a consumer mentality and the PLUG and PLAY concept to everything today.
They also believe in what the slick middle men and dodgy marketing commercial people say and tell them.
These are normal size households with teenagers etc, What I general see is this.......... They want total independence, they have 5KW of PV, a standby second hand generator, a Chinese cheap PWM battery charger, 220ah 96v gel batteries, a cheap Chinese 96v Inverter to 220vac max output at 3Kw. Cables to important bits are way undersize in thickness and connections are real bad. They manage for a few years and struggle in the Winters with the generator running most of the time. I also see the Grid tied folk with Hybrids, but again the hybrid and little battery pack just does not cut the mustard in the winter months.
Can i help them with impartial independent advice, and cost-effective solutions?
Now where the heck do i start. Firstly, i realised I am up against the social culture straight away. Now, these folk that ask me are what i would call ECO warriors type. But i find that their Philosophy of what they are doing clashes with reality of a long term stable independent electric supply for their house.
So I do A4 size handouts in their language for the other folk in the household to understand why certain things are necessary and to operate the changeover switches and generator battery charger etc. I had to do those A4 handouts sometime so in a sense they are good info for anybody.
The blokes in the household understand to a certain extent and want to learn but there is a point when even there eyes just Glaze over.
I go with the mentality of best cost, best quality, and a 20 years life span.
And as my Mrs says to me “Your OzInverter is great but it’s just too complicated for ordinary people to fully comprehend” , I wrote a A4 handout and she made it readable how to properly start a ‘OzInverter’ in sequence. But still the teenagers pressed the Control board reset button inside the case, while the OzInverter was operating oh dear!
Depending on the abilities of the Household, I now recommend 2off simple ‘Victron Phoenix’ 5KV, they have toroid’s, a Dutch company stuff made in INDIA, with RJ45 connected as they can be sequenced for 50HZ, also getting a third also means you can have 3 phase supply. Although I hate software, this Victron stuff is not difficult to implement and plenty of info on the WEB etc.
As a good quality and proven battery charger I recommend the ‘Midnite Classic 200’, USA made. As most modern PV panels have a higher voltage than the old PV. It can handle input 200vdc at 78 amps so can run nicely on 15KW of PV.
Batteries I still recommend Lead acid, ‘ROLLS’ or forklift type ‘OPZ’ and about 1200ah 48v that’s about 60KW. I normally recommend 3 banks at 400ah 48v each.
240v Generators are a pain as they always want to be top dog and getting them to link with an inverter HZ is never really successful long term. So, I recommend a changeover switch system, that links to the generator and also links in the generator charging the split battery bank individually, (stops any sh*t feedback from the second-hand battery chargers and generator, getting at the Inverter and PV Chargers).
AC coupling, for the ‘OzInverter’ its no issues. For the ‘Victron Phoenix’ there is a function in its software that will allow the machine to back feed AC to the battery bank like the ‘OzInverter’ does.
Once over 15KW PV, and in the winter months you never have enough PV, then I get folk to do separate PV arrays that are directly linked to Old/second hand toroid GTI’s and to the 240vac MINI GRID the main inverter is creating. What this does is to direct feed the 240vac Min Grid. For the OzInverter it can take 11KW of GTI AC Coupling back feeding to the battery. You will need to use the auxiliary contacts on the ‘Mindnite Classic’ controller to shut down the GTI’s when the batteries are fully charged and you are not using the GTI’s to produced power. Please use small GTI’s max 2.5KW as above this there are surge issues, but having the arrays say 50 meters away, then voltage drop on the cables becomes very useful.
If you have 48vdc output Wind turbines and these are direct connected to the battery bank as a load, then you will need ‘Tristar’ USA made, Diversion controllers, these can also be used to divert excess AC Coupling feed back that gets to the batteries. 240vac Wind turbines can be connected to the 240vac Mini Grid with a suitable GTI, but you will probably need a Load for a 240vac Wind Turbine.
If you think this post could be put into its own Subject Posting, then I will do so. Hopefully the above helps. Edited 2022-06-20 19:06 by ClockmanfrEverything is possible, just give me time.
3 HughP's 3.7m Wind T's (14 years). 5kW PV on 3 Trackers, (10 yrs). 21kW PV AC coupled SH GTI's. OzInverter created Grid. 1300ah 48v.
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 12:20am 21 Jun 2022
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Clockman, thank you for your thoughtful post and information of Frances approach to renewable energy.
I know well that glazing over of a recipients eyes as you try to explain things I have seen it many times before.
The mini grid approach that you use with the AC coupling is a great solution. Its simplicity of using available GTI's which with solar has the effect of minimising the OZ inverters load and it becomes mainly just a commutation provider for the GTI's to kick off. The fact that the OZ inverter also allows back feed for the batteries is also a bonus and its ability to take over & share more load if the solar reduces due to clouds etc is well thought out.
Your advice on the various components is also appreciated, real world experience is always a winner for me. The Midnite classic has been mentioned a few times before, but I never warmed to the name - it would be asleep at that time, Maxiday or Highnoon or some other name seems would have been more appropriate.If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
poida Guru Joined: 02/02/2017 Location: AustraliaPosts: 1418
Posted: 01:54am 21 Jun 2022
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I have a change over relay, 40 Amps 240V AC. This has a primary input and a secondary input. If there is primary input, then that is used. if no power on primary, then it changes over to secondary input.
Output is to the house to supply various GPOs. change over speed is far less than 50ms
Street power is connected to secondary. Inverter output is connected to primary. I program the inverter to stop when battery voltage is too low. Inverter restarts when battery voltage gets to "high enough" next day The battery is charged to whatever extent by the two mppt controllers.
Totally automatic and intervention free.
Secondary input to relay is via the 35A circuit to the cook-top and so has no RC safety, just a CB. All of the GPO's are after a RC safety breaker.
Backup systems: a 2kVa generator, to do one thing: charge the battery via an Eltek 2kW PS and the Eltek PS, which also has capability to be powered by street at times when future street power outages are planned or expected due to weather. This saves using the genny.wronger than a phone book full of wrong phone numbers
wiseguy Guru Joined: 21/06/2018 Location: AustraliaPosts: 1156
Posted: 09:00am 21 Jun 2022
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Thanks for the description of your setup Peter. I guess it shows that there are many different and sometimes conflicting requirements, to try to get a one size suits all answer is a big ask.
I went and had a look at the switchboards in my house to see where I might locate a contactor to at least isolate me from the mains if I give a whoa camel command. This of course also assumes that I have settled on what approach I take for my given situation - which I haven't yet.
I feel depressed each time I look at them and realise I have a lot of work in fron to of me trying to trace each circuit and what exactly they are all hooked up to.
Some pictures of my dilemma
& &
I think the only place for the contactor is the middle picture the top one is a nightmare of wiring behind the front panel no room for anything else.If at first you dont succeed, I suggest you avoid sky diving.... Cheers Mike
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