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Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 09:22pm 05 Jan 2018
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Boppa I am very interested in some more details about your setup as the property I am buying has a big 18 X 8M shed with the centre of the roof right on north-south alignment.
Can I ask what is your latitude and how much power do you get at midday in full sun?There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 12:22am 06 Jan 2018
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What angle do you have the panels at Bop? I am of the belief that when they are off north so to speak, the shallower they are to within limits, the better they generate.
I haven't crunched the East/ west numbers. I have a mother of a tree that's noted as the largest in the area in the front yard. May have been a mistake buying with that there but I'm here now. It's 4 times the height of the house and spans at least 3/4 the width and the house is 25M wide.
Am would be a complete write off for east panels and by the time the sun cleared the tree, the west panels would be in full sun. Luckily I have the north face completely clear and loads of free space on the west as well.
I want to get 10Kw of panels up all together. I have 7 On the shed now comprising of 5.5kw of 250's and 1.5 of 190s. I'd like to get another 5Kw of 250's or above on the house and then look at maybe moving the 190s to the west face for hot water boosting.
In two minds about the hot water. and will see how I go with 10KW. I get/am charged .30c KWH for the regular power but only .11C for off peak. Unless I am over generating on the regular power, diverting to the hot water is not cost effective.
I think I'll over generate easily ( made a hard to fathom 37Kwh yesterday) in summer but winter will be the test when the solar generation is half of summer and we are using the AC for heating. that's when I'll be taxing even 10 KW I reckon. If I can find the panels, I'll happily buy another 10KW worth as I rather have too much capacity than not enough.
Just emailed the guy I got the last batch of 250's from to see if he has any more. If he does I might see what sort of deal he'll do for me for 40 panels. Seems everyone round here has a $1200+ power bill so really can't go wrong investing in panels.
Calculating my next bill to be about $300 when it's due middle of next month. So far have used about $30 worth of Power on the phases I'm back feeding plus there will be $100 " Supply" rip off for the quarter plus about $100 for the electronically metered phase which has the AC and the off peak on it.
I'd like to find a devise ( at a reasonable cost) that feeds the amount being consumed when available from the solar into the phase and no more. My electronic meter charges both ways for power so I could be giving the grid power and paying them for the privilege as well IF I just back fed without a controller.
Not sure what these things are called but I'd like to find one or better still a how to with arduino or something.
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 07:38am 07 Jan 2018
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Sorry for the delay, got a mates kids lurgy over new years ugggh
panels face almost exactly east and west (north is about 5 deg off the ridgeline), about 30 deg angle on them from horizontal In Brisbakers so whatever latitude that is
looking at todays figures so far it was 1kw @6.40am, 2kw @7.20, inverter hit its limit 5kw @ 10am stayed there till 2pm , 4.40pm was still 2kw, last reading was 5.30 and still over a kw (just) Total for the day so far was 36.4kwh
The inverter flattops at 5kw (I suspect the panels are capable of producing more as they are 5.5kw rated, but I think the software is throttling it back to the 5kw limit imposed by the elec mob) as it basically is at 5kw from 10 till 2
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 08:37am 07 Jan 2018
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Thanks for that, I am just up the road at the Sunshine Coast, latitude here is 26.5 you would be somewhere around 27. At present, I get very little unless it is cloudy before 8.30 due to row of very tall palms 10m away on the eastern side. That will all change when we move. There are only 10 types of people in the world: those who understand binary, and those who don't.
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 09:54am 07 Jan 2018
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Just went out and checked it, 37.5 for the day total
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 10:56am 07 Jan 2018
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I have got 37KWh the last 2 days from my 7 Kw and I was pleased with that. Perhaps the radiation is better in brisvegas than Syd? Everything else is better up there, maybe I should have just bought a house on the goldy and THEN told the wife and daughter instead of asking and having them Kybosh it first.
Your inverter will only do what your inverters capacity is. If it's 5KW you might get about 5010W and that will be it. You can put 10 Kw of panels on it and it will max out at its rating and that will be it but you'll find in that case it's doing 5KW from 9am to 4PM instead of the 4 hours you are getting now.
My generation was well down today even before it got cloudy. It was a cosy 45o C here and like a moron, I forgot to put the fan on the inverter. It's in a well ventilated shed thanks to a couple of car radiator fans running off a cracked 300W panel blowing a gale in there but stuff that inverter gets hot. Of course the hotter they get, the more they back off to self regulate the temp.
I have an inline fan I sit on top and have blowing down through teh heat sink at the back and over the front as well. I forgot to turn it on today and when I went up there just before midday, the thing was too hot to touch. Straight off I noticed the KWH was well down on the previous 2 equally sunny but much cooler days when I had the fan on anyway.
I turned it on and turned up the speed and the heat coming off the thing would have outdone several fan heaters by a long shot. Must weight nearly 20 KG so it's a good thermal mass to start with. I had the fan going about 10 min then came back and noticed the output had gone up nearly 300W even though the light hadn't changed and the other inverter which has an internal fan and runs much cooler was still doing exactly the same output.
This inverter is 5KW and only has about 4 Kw of panels connected so isn't overloaded by any stretch but the heat it puts out is a worry of inefficiency. I came back an hour later and the thing was still pretty damn hot but nothing like what it was. I don't know how these things can survive where they might be mounted on a wall with the sun beating down on them and why the heck they don't have internal forced cooling.
The output had gone up another 700W which was in part due to the higher sun angle but also had to be because the thing wasn't at melting point any more.
I have ordered some thermosistors to put on the thing so the fan will start automatically at 40oC. I reckon pulling the front cover off and drilling a heap of holes in it and a large one for a fan for internal cooling wouldn't be a bad idea either. I'm happy to keep it in the shed out the weather and it would have to last longer running maybe 30o or more cooler.
The clouds came over pretty heavy about 2:30 so I knew that was going to kill any chance for a good output day but still finished with 31 KWH which was a lot better than expected.
Week one of the year has been good for generation, nearly $60 worth of power at what I pay.
Probably used $100 worth just on the air con though. :0(
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 11:45am 07 Jan 2018
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The issue I see is that with a pure north facer with 7kw plus, the inverter has to dissipate a massive midday peak, where the east/west facers have a lower peak (closer to the inverters ideal max) but spread out over a longer period of time- my thinking is that in the end you will come out ahead- I got that 37kwhr total on only 5.5kw of panels
I think that ne and nw panels would be even better, but at this house it effectively had to be the two strings east and west due to the roof design. I had reservations it would be able to even get to the performance of a single north facing array of equal size, but I think it is actually outperforming it, given the 5kw limit imposed by the grid connect itself. You could put 10kw of panels on a norther to bring up the hours you get usable generation, but your inverter will be hard pressed during the midday peak and on a grid connect you still get limited by the 5kw limit for exporting to that 5kw out- effectively you are wasting that extra 5kw during the peak just to get the extra output early and later, this system is doing it with only 5.5kw of panels
It would be interesting to set up several 'temporary' setups, identical panels and inverters at the same location, with 2.5kw east/2.5kw west, same ne/nw, 5kw north only and combination setups, like 3kw north/1kw ne/1kw nw with full logging so you could compare the actual figures (peaks, start/stop times, total kwhr generated etc)
I suspect a lot of solar 'truisms' might not stand up to a close scrutiny... of course an ongrid with its 5kw limit may be different to an offgrid for battery charging as well
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 12:28pm 07 Jan 2018
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I don't get it in the morning due to trees but in the later afternoon the flat panels are way ahead of the north facing 26.5 degrees ones. The angled ones end up with the sun shining on the back of them and the flat ones are still able to produce close to 2KW. As I am using mine off grid I am usually in float at that time, however it then comes into the evening peak usage. So between 5 and 6PM the angled panels are hardly doing 20 watts, but the flat ones are still making several hundred watts. If I had panels tilted up towards the west it would no doubt produce quite a bit more power late in the afternoon.
Having the perceived optimum angled north facing panels is certainly not the be all and end all. I plan to end up with 20KW of panels 10 facing east and 10 facing west at about 18 degrees which is angle of the shed roof. This is not to be able to produce 100KWH plus a day but to be able to get 20KWH a day when the sky is dark.There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 12:47am 08 Jan 2018
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I am on grid but have also come to this conclusion. Peak power on a sunny day is easy, making worthwhile power when it's cloudy, or winter, is what the real challenge is. Even during the day, you want to stretch that " Powerband" as wide as possible.
The 5 Kw restriction is a crock to save the power companies loosing too much money. To surmise the grid could be overloaded with backfed generation is garbage. in order to o so, EVERY house would have to be producing more than it's peak load on the grid because if it can go one way, it can go the other. Even in saturated areas, I doubt there is more than 1 in 4 places with solar and even if there is, shops, schools, offices etc are never going to be that far away so the power input is going to be dissipated pretty quickly.
I want to put up 10 Kw of panels because of the much lower generation I'm going to get in winter when I still want the AC for heating. 5Kw is not keeping up now in summer with the AC, only going to get worse in winter when the output falls through the floor.
It's overcast here today so it will be interesting to see what the falloff is. Been doing in the 30's all week, reckon I'll be lucky to crack 20 KWH today but that said, have also learned cloud does some really strange and surprising things. having my panels at 5 and 13o will no doubt be an advantage again.
Google earth shows there are only 4 houses out of 26 in my street that have panels. Given the amount of retirees and home businesses in the street, any power those of us with panels do backfeed is not even going more than 2 houses away.
For me putting panels north is still the better option although I have thought about the north and west split. The main problem is the roof pitch which is 34o nd my " ideal" latitude is the same. At first I was excited and amazed at this being so much steeper than normal but now I have learned more and see how much better the flatter panels are, it's a disappointment. If the rood was 22 like a lot of places the west aspect would be a lot better.
I don't know if any of those small charge controllers have the facility to record output. IF there were any that were fairly cheap they could be set up with one panel and a suitable load to test the different angles and aspects.
That said, there are a lot of online calculators that we should be able to punch the numbers into and get a result.
That's How I learned the North at lattitude angles was far from ideal.
Boppa Guru Joined: 08/11/2016 Location: AustraliaPosts: 814
Posted: 01:11am 08 Jan 2018
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just so you can see the angles
HWS is on the north face, north/south ridgeline is about 5 deg east of north according to the boats compass (dont know how accurate it is sitting on the metal trailer tho) The other array is identical on the other side but I cant really photo it unless I go ask the neighbours if I can go in their backyard to do it lol
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 02:45am 08 Jan 2018
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If you had a micro inverter with monitoring and data logging you could get some very good comparisons. Sounds like a good research project for a University.There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 09:16am 08 Jan 2018
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Cloudy, hot and bloody humid here today.
16Kw all up.
Going to have to get me those extra 5kw of panels. With those it might have been a respectable yeild!
Found a good deal locally on 2KW of 190's so decided to grab them as well.
noneyabussiness Guru Joined: 31/07/2017 Location: AustraliaPosts: 512
I really hope our idiot gubberment doesn't follow suit. .. it will be even harder to get cheap panels. ..I think it works !!
renewableMark Guru Joined: 09/12/2017 Location: AustraliaPosts: 1678
Posted: 07:43am 23 Jan 2018
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We don't make panels here AFAIK so there is no industry to protect.Cheers Caveman Mark Off grid eastern Melb
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 07:47am 23 Jan 2018
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I doubt Australia would do the same trump AKA Biff is trying to pick a fight with china Australia is not.Edited by Madness 2018-01-24There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 10:08pm 23 Jan 2018
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Been a load of cheap panels on Gumtree of late.
Picked up a 4 Kw system 2 weeks ago with Microinverters, panels and rails plus all fittings for $550. Yesterday picked up a 3 KW system with inverter, rails and fittings for $350. Could have got 11x 190w panels for 250 but timing was off with seller who was going to be out all day and I wasn't going to wait around so passed as it was round the corner from the 3 Kw system but over an hour from me.
Have another one I'm arranging pickup of 6x250W panels for $200.
At the rate I'm buying them, I'm thinking to get a heap more panels and use them as the roof on my new pergola. They are working out much the same price as roofing anyway but the roofing doesn't give me savings on my power bill. Rate I'm going, I'll be able to sell power back to the neighbour!
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 07:59am 19 Feb 2018
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Picked up another lot of panels today from Gumtree. 20x 250W or 5 KW. Got wiring, switches and other stuff with them. $500 or $25 per panel. Pretty happy with that. Tested them all and they are working well.
Think that will probably do me for now. ATM I have 8.5 Kw worth on the shed, 1500W on the pergola, I'll put this 5Kw on the north end of the house and I have 4 Kw worth still to put up. My father wants me to put some on his place so I will probably take 8 190's off the shed for him, take the others on that side down and put them on the west side of the house and put the other 4Kw up there. I'll run the numbers to see where the 240's are going to do best. On the 13o south side of the shed or the 34o west side of the house.
That will give me 5.5 + 4kw on the shed, 5 Kw on the north side of the house and 3KW on the pergola and west side of the house. Still have room left but I think that should do it even for winter.
I sold half the Microinverters I got previously with the other set of 240W panels on the weekend for $250. Paid $550 for the 16 Panels, 16 micros and racking etc. so almost half my money back there. Makes them $300 for 16 240W panels or $18.75 per panel. If I sell the other micros, I'll really be laughing.
There have been less panels coming up the last month or so but still some really good bargains to be had. I missed out on a set of 20 260's the other week, 20 of them with a 5kw inverter for $400. Very cheap power.
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 08:50am 19 Feb 2018
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Haven't seen any 250W panels anywhere near that price around here for while. 5KW of panels wuth Inverters are selling at around $2k on ebay.There are only 10 types of people in the world: those who understand binary, and those who don't.
George65 Guru Joined: 18/09/2017 Location: AustraliaPosts: 308
Posted: 11:10am 19 Feb 2018
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Which to me is overpriced. The people taking them off the roof are probably doing so to put new panels on which would cost them 4-5K for a 5K setup with rebates and they would get a guarantee with that on the panels and inverter.
I see this a lot. They take off an old 2 KW system to put on a 5, and then have the gall and stupidity to ask 75% of the price of the new setup because they paid $10K for the old system 6 years ago.
Ummm, you didn't pay $10K for it idiot. You also paid significantly for installation, wiring, switches and other things which are either now gone or useless. Further more you also got a .60C FIT for 7 years or so which more than repaid the interest free loan you probably got to finance the things and you have realized a saving on your power bill if not been in front all that time. It owe's you nothing, that's why you are putting on a bigger one!
I'm sure these are the same clowns that come in and want to sell their car which does not have a straight panel or a mechanical part on it which isn't clapped out and then rave on about what they paid for the thing new 22 years ago! I often tell them, " Looking at it now, it's hard to believe it was new once isn't it?"
My favorite thing when they tell me the guaranteed " It's a good car!" line is to ask them to point out with precision and detail, exactly what is good about it or what the good parts are because I seem to be missing them. I have literally been told it has new windscreen wiper blades!
Well! In that case then, it must be worth the stupid amount you think it's worth!
Madness Guru Joined: 08/10/2011 Location: AustraliaPosts: 2498
Posted: 12:09pm 19 Feb 2018
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Anything and everything is worth the same amount, what someone is prepared to pay for it.There are only 10 types of people in the world: those who understand binary, and those who don't.
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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