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martrogers
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Joined: 15/09/2019
Location: Australia
Posts: 11

Posted: 06:06am 18 Aug 2020

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Hi

I have recently replaced my 1.5kW system with 6.6kW panels on a 5kW GTI. I asked to keep the old panels and inverter. I have spare roof area which could accommodate the old panels.

Would it be possible to reconnect the old system or would the inverters fight each other? I have seen somewhere that it may be OK but depends on the inverters.

The inverters I have are

1.5kW SEA Orion model SPG-360-2K0 nominal 2kW
5.0kW Solis Model Solis-1P5K-4G-MX

Would appreciate any advice on this.

Regards
Martin

Warpspeed
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Joined: 09/08/2007
Location: Australia
Posts: 4406

Posted: 07:07am 18 Aug 2020

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Welcome to the Forum Martin.

I suppose if you have a grid tie system, and your neighbor has a grid tie system, and his neighbor also has a grid tie system, all connected up to the same street power, its exactly the same as you having two systems....

What the power utility ALLOWS you to connect up is an entirely different matter.

Technically there should not be any problem, and with a very careful reading of the rules it may even be allowed, unless its definitely forbidden. �
It really comes down to your attitude, and interpreting the rules and regulations �

It obviously all needs to be installed in a safe and professional manner.
Only real worry then, is if you ever need to make an insurance claim.
An insurance company will always use any pretext they can find to weasel out of paying up.
Edited 2020-08-18 17:14 by Warpspeed

Cheers, �Tony.

ryanm
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Joined: 25/09/2015
Location: Australia
Posts: 191

Posted: 09:07am 18 Aug 2020

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A lot of the folks on this forum are gung-ho on safety, but not as much for legislative compliance.

Personally I wouldn't bother with the effort. If you have to call out an electrician you're not mates with for an emergency they might dob you in. I think they might even be legally required to. Most states have some pretty serious fines for hooking stuff up to the grid you're not supposed to.

On the technical side I agree with Tony though. If it is wired in correctly worst case senario is both the inverters have internal shut offs and you lose a few kWh while you figure that out.

Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 1577

Posted: 10:53am 19 Aug 2020

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I'm Currently running 4 inverters on 2 phases and have had up to 3 Inverters on one phase. Technically, within output limits, you could run as many as you want. Never had any problems except if you try to push too much power on the same circuit you will get voltage rise and the inverters will shut down when they hit their safety limit. No big deal, once the voltage drops to their preset level they kick in again.

I had a voltage controlled relay on my Hot water system to allow for this. It kicked in when the voltage got too high and pulled it back down again. Time the water was hot the sun had tailed off and the things were OK again.

If you have just a 1.5 system you can just plug it into a power point. No where near capacity of an outlet or a power circuit. Your new install will be on it's own circuit so unless you have a problem with a High tapped transformer in the street, you won't have any voltage rise problems especially as anything on that circuit will be pulling power anyway. No need to hard wire it, just plug it in like anything else. I have a 4Kw inverter doing that now but it's not doing full power. Just want to test the thing for a bit.

As for all the legalities, that's up to you. Just decide if you want to do it by the book or not.
If not, that's it, can't do it, your old gear is not on the approved list so can't be re installed. End of story.

IF you are not so concerned, then you have a lot more scope.
Personally I don't give a rats about these over the top rules and regulations.
The solar rules and regulations are a complete and utter joke and contain some very proven unsafe requirements like the well known rooftop isolators that are renowned for causing fires. There are so many damn regs that a number of them are completely conflicting. You can't abide by one less you break the other.

All designed NOT for safety but to keep the solar industry profitable.
You can leave that old system on your roof forever BUT, having removed it you now can't reinstall it because it's not safe. what a crock! ALL my systems are used and never had a problem yet and won't have one either.

My arrays are non compliant ( apart from the fact I installed them myself) because I won't have rooftop isolators ( such a joke even the fire brigades are against them) and I have too many Circuit breakers and am running a sub Board. The beauty of not being compliant is you don't have to worry about their stupid standards.
Like a lot of standards, most of the solar requirements are profit based. How to get the bare minimum safety in the fastest possible install time at the least cost to the installer.

MY standards are that I have to live in the place and have all my valued possessions in there so I'll do it to my satisfaction so I sleep at night. I have seen several solar installs done by " Professionals" as well as seen what's been done with used systems I have bought and they have been a joke. Turned one system a Mate had installed 3 years ago off and told him not to touch it till he got a sparky with a brain to do it over properly.

I hear a lot of people talking about if the power co discover you. When did you ever have anyone from the power co come out and do a random inspection for no reason. They would have to give you notice for a start. I recently sold 4 KW of panels to a guy who works for a power co. I raised the thing about them picking up on his rise in FIT> he laughed and said he'd worked for them for 16 years and they couldn't even get the basics right with peoples bills and connections and everything else, they certainly didn't have time to pay attention to things like that!

Thinking just because you got someone whom is supposedly licenced to do something makes it safe and trustworthy can be a literal fatal mistake., Have a look on some of the solar discussion boards and see the endless trouble people have.
Personally I wouldn't let a solar installer near my place without watching everything they did. I'm sure there are a lot of good ones out there but I KNOW for a fact there are endless monkeys as well.

-If- you are competent in electrics there is no great trick or complexity to solar at all. It's very simple. I have around 25 Kw of panels on my roofs atm which I installed myself and I made my Highest output the other day of 97.1 Kwh. Waiting for the weather to clear again so I can crack the 100 Kwh mark for a day.

If you pay attention to the normal things you would do when wiring anything permanent you are fine. You are not supposed to plug an inverter into a power point, it's against the regs but if you do, you also get round a lot of other regs.

There are other things you can do to get round regs as well. For instance you could have the panels on a controller going to a hot water heater in front of your regular heater. The 2nd heater connected to the panels only and is off grid so rules don't apply. If you had that heater feeding the main one and pre heating the water, then you would save on water heating costs and be compliant.

The thing with insurance always looking for a way out is True but often over stated. They can't knock you back on insurance when you had a fire due to a faulty Fridge because you were running an unapproved solar installation. IF the solar was the cause of the fire, then fairly enough, you are out of luck. Take your chances.

I do and sleep very well at night with all I have done thanks to being able to heat or cool the house with the power my solar provides which I certainly couldn't afford otherwise to use as I do.

Bottom line is are you concerned about being compliant or not?
If you want to play by the rules then the answer is NO, you can't reinstall this system as a grid tie.

martrogers
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Joined: 15/09/2019
Location: Australia
Posts: 11

Posted: 08:06am 21 Aug 2020

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Thanks guys for your time and advice. I am of the Davo line of thought. As a Structural engineer I have sat on code committees and have seen how they can be stacked by industry representatives On a recent code update I heard that the reinforcement industry threatened to sue the committee if a new clause which mandated more reinforcement for some elements was dropped - I cannot verify this but it wouldn�t surprise me.

I�ll give it a whirl and monitor the situation as the sun comes up...

Thanks
Martin

Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 1577

Posted: 02:25pm 21 Aug 2020

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let us know how you go with it.
Will you be installing it on the same direction roof as the main system or in another direction?

I have north and west facing panels and I'm very happy with that split. having 2 Directions give a better power constant over the day and the west aspect is definitely the best for summer.

I did some number crunching the other day on tilt. I found going 20o off ideal makes bugger all difference and even 30o isn't all bad, in fact it will be better over some period that the latitude tilt.

If it ever stops raining and blowing here, I might be able to get the last of my system done.

martrogers
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Joined: 15/09/2019
Location: Australia
Posts: 11

Posted: 07:46am 22 Aug 2020

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Both roofs are approx 30 degrees to the horizontal and 10 degrees east of north. The 1.5kw roof has some tree shade especially in winter but at a 20c feed in rate every little helps.

Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 1577

Posted: 12:26am 23 Aug 2020

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Very similar to my north roof.

If you have a clear west roof that would be an option. You'd probably loose a little in winter but gain a while lot more in summer.

While you are at it, if you have the space you could see if you could find some more used panels and put them up too. Overclocking the inverter will make you more power earlier and get the inverter up to full steam longer in the day and let it taper off later. You'll also do a lot better in overcast weather.

You probably only have a single Tracker on the little 1.5kw inverter so would be good to match the panels pretty close. If you have 190W panels you could put up 195's or 200's. The bigger panels will only run at a max of the smallest in the string but they will play happily otherwise.

If I have to go semi legit I want to do the same thing. Put in a little system so I can get a fit ( if they still exist then!) and run what I have now as well to milk the mongeral power companies for all they are worth.

20c is a good FIT. What do you pay for power? I was looking at some " Plans" ( moronic term!) the other day and it seems for the most part, the higher the FIT the more you pay to buy. I would be trying to make all I could as well to offset the buy price. While the 1.5 may not be worth that much on the fit, if it offsets some of what you but then that's the price that power is actually worth.

I was talking to a guy earlier in the week that is in VIC somewhere and he says he pays .26 Kwh and is on a .72 C fit. Wish I could hook up to something like that. I'd be a well off man.

martrogers
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Joined: 15/09/2019
Location: Australia
Posts: 11

Posted: 09:55am 26 Aug 2020

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I had a look at various plans when mine came up for renewal. Knowing the real output of my system over a number of years was very helpful. I had built a small Micromite based data logger which used the Orion RS232 port to record inverter output at 10 second intervals and summed into half hour periods which could be compared with the electricity company readings of net usage downloadable from their website.

Anyhoo, the best plan for me was:
AGL Solar Savers Plan
Solar feed in 21c
Peak. 47c
Shoulder 21c
Off Peak 13.7c
Supply 94c/day

Davo99
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Joined: 03/06/2019
Location: Australia
Posts: 1577

Posted: 02:26am 27 Aug 2020

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I suppose something like that isn't too bad.
Seems common you Pay about 2.5X what your fit is. As you can get a 1:1 or 1:2 on what you produce, could be OK depending on what hours are peak.

I looked them up and they seem to vary a lot depending where one is. Would have to manage loads carefully or one could get stung bad. Having to check when I could do things and schedule what I was doing according to power companies for what I pay would not suit me at all. I'd literally have NO hope training the women to pay any attention to that either.

I notice there are flat rates available still and that would be what I would go for myself for my circumstances. Others may be able to game the system better with TOU and I hope they can. No sympathy for Power cos what so ever.

I have shut more than half my arrays down for the moment. I made a peak of 102 Kwh one day last week but was getting too far ahead so I have been burning power off.
Out main usage is at Night in winter for heating which is why TOU would not suit me at all. Then again, -IF- I could hook up what I have which would be unlikely, I may be OK.

I would look at heat storage by Pumping daytime power back into a 400L Hot water system or 2 and then circulating that back through a radiator at night to heat the place.
Benefit of this is I could also Co gen with an engine in bad weather and get power and heat. Going to ask a mate in AC about Chillers so I could cool the water in summer to store in the tanks and use at Night also.
The other option on that front is the spa we are putting in. 2000L so would have good thermal mass for heat anyway.

All these DIY power saving ideas are good and well but actually building them so they don't make the house or garden look like a junkyard while still being practical is the trick. The water heaters and Spa could be made to work and still not be an eyesore.

martrogers
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Joined: 15/09/2019
Location: Australia
Posts: 11

Posted: 11:09am 31 Aug 2020

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martrogers
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Joined: 15/09/2019
Location: Australia
Posts: 11

Posted: 11:10am 31 Aug 2020

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