Author Topic: Solar Array Install  (Read 13895 times)

warlock

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Solar Array Install
« on: July 31, 2013, 08:29:30 AM »
Ok so here is my planned Solar Array..... Many thanks to ExSolar

10 x 250W PV
10 x i-Energy GT260 Micro-Invertor
1 x i-Manager


This to start and looking to grown it every 2 months  by 500W for 10 months.
I am hoping to put my order in early next week, and will update with pictures.
If anyone can see an issue here please let me know.

« Last Edit: August 21, 2013, 03:58:17 PM by warlock »

warlock

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Re: Planned Solar Array
« Reply #1 on: August 07, 2013, 07:36:01 AM »
Right so the order has been placed and delivery expected next week, I have down sized to 1kW for the initial install and will then grow for there.
As soon as the kit arrives I'll take some photo's

warlock

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Re: Planned Solar Array
« Reply #2 on: August 21, 2013, 03:57:58 PM »
Ok my kit has arrived  ;D
I have not unpacked it all yet but I will supply photo's as we go along.
I have strated the install and have got all the roof hooks in, I finished off in the dark so could not
get a picture of it complete but I'll provide what I have and update as we go along

Rook Hook Installation

warlock

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Re: Solar Array Install
« Reply #3 on: August 21, 2013, 04:14:54 PM »
As I had said before I decided with the micro-inverter route, for 2 reason, 1. Far better shade tolerance and 2. simplicity of the install.
To install this like all or most micro invertors I simply daisy chain them to each other and thn from the last one in the line I connected 2.5mm surfix cable which runs directly into on DB board to a 2P 20A AC breaker and then from that break into the out of the mains switch.... I have no need to worry about DC cables and high voltages ect.


i-energy micro inverter and i manager

SeanB

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Re: Solar Array Install
« Reply #4 on: August 22, 2013, 12:44:05 AM »
1kW will do nicely to offset the daytime load in most probability. You probably will show zero power draw over the day, and if you have a mechanical meter it might run backwards as well as you feed power in to the grid. I would suggest a second meter bought from Litecorp or such to get a reliable figure of the power the panel array is generating. I would also suggest the next string has a separate run of 2.5 surfix to the DB , though you can use the same breaker to feed the power in. That way there is less loss in the cable and the inverters will be less likely to do an overvoltage trip on a sunny day.

warlock

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Re: Solar Array Install
« Reply #5 on: August 22, 2013, 01:55:23 AM »
Thanks for the feedback Sean,

The I-Manager which I have also purchased, communicates with each individual micro-inverter, this allows me track the total power production and the individual panel production, it's quite cool coz then if there is a problem with a panel it will allow you to identify it from the web interface.
I do have a mechanical meter and from what I have researched I have found other people on the internet that have this same model meter running backwards so unless Eskom has done something clever "which I doubt" I should be good there.

With regard to the surfix, I might have it wrong but I am installing 2.5mm which is rated to 20A and 4000W, the i-energy micro-inverters allow up to 17 in a string for a maximum of 20A, so I am installing a 20A 2P breaker in the DB. the surfix run from the panels should not be more than 5m, so with this regard I should be good to my eventual install of 3kW,

If I am wrong please tell me before I install this surfix, by I was looking at the cables on the inverters and they too are only 2.5mm, I could always just install 4mm just to be safe ?

I have attached 2 more photo's I took this morning, I'll hopefully get the rail's, copper grounding and surfix in this afternoon.

SeanB

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Re: Solar Array Install
« Reply #6 on: August 22, 2013, 01:27:08 PM »
If it is only 5m or so you will be fine. The worry comes with a 30m length, which typically will have a 10% voltage drop along it, so the inverters will have to generate a 250-260V output to cover the cable loss. If you can put in a 4mm cable then do so, lower losses of the power you are generating is always good, and saves you later having to arrange a new run of cable to the panel connection. At the panel end I would also recommend a small York box with the connections inside so it is easy to add the extra panels in later stage as you expand. If you really want there you can use a small DB panel and just have 2 pole isolators inside to enable each string to be isolated from the system with ease.

warlock

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Re: Solar Array Install
« Reply #7 on: August 22, 2013, 04:18:19 PM »
Cool shot for the info, I was thinking about it today and it's only like R30 more for 4mm cable so it's a no brain er to go for 4mm, I'll let you know how it goes.


warlock

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Re: Solar Array Install
« Reply #8 on: August 25, 2013, 05:49:32 PM »
Ok so I managed to complete the install and happy to say I am feeding back into the grid.

1. First things first I rewired my DB, I replaced all the old style breakers with new breakers, I have a few more to change to
make them all uni-form, but I will do that over time.

2. I installed the rails onto the rook hook that I install

3. Attached the inverters to the rails

4. Mounted the solar panels.

Lastly flip the switch on the DB and presto we have power.

SeanB

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Re: Solar Array Install
« Reply #9 on: August 26, 2013, 01:14:07 AM »
Looks a lot better, and with the panels you now definitely will have a saving.

MJLorton

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Re: Solar Array Install
« Reply #10 on: September 05, 2013, 08:37:50 AM »
Excellent stuff, you are playing with bits I hope to experiment with in the future. I think you have made a very wise choice in going the micro inverter route and being able to monitor each panels is such a bonus.

I want to put to 3 equal arrays side by side, one with grid tie, one MPPT CC and the other micro inverter to compare performance.

Thanks very much for your post.

May I ask how much each micro inverter cost and the I-Manager? I'm keen to see if this system costs much more than a normal grid tie?  Still worth it in my opinion!
Play, discover, learn and enjoy! (and don't be scared to make mistakes along the way!)

warlock

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Re: Solar Array Install
« Reply #11 on: September 23, 2013, 12:32:15 PM »
I am fortunate enough to be able to run a small business so I get the equipment at dealer cost, but basically it cost about R2750 per invertor, each can do 240W-260W I have 250w panels attached, so for 2500w or 2500KVA it will be about R27500. 

Since my last post I installed a further 4 panels so my array is now 2KW, and I have to say that I must at least be getting > 20% more production than a single string inverter. With the I-Manager "R3500" you can see historically and realtime, that often during the day as cloud's, tree's  and morning's and evening as shadows effect the panels, 6/8 of the panels still producing 200W+ and the other 2 100W-120W and as the shadow shifts you can see it move on the array.

I am very impressed, the only thing is my roof is at about 18deg and we have just come out of winter where the inclination should have been like 56deg. So not good for winter but, mid to end spring they'll be perfect, for or summer months 2deg is optimum.

The installation was a real breeze and I did it all my self .With the i-enegery inverters you can connect a maximum of 17 on a bus, I say bus because each micro inverter is connected the next and so on and so forth, but the string acts as a busbar, so if one would fail the rest would still operate without hindrance. Then from the roof I used 2.5mm surfix under the roof tile and directly into a 2 pole 20A circuit breaker in my distribution board, from this breaker into the out of the mains 63A breaker. As simple as that and it complies with all safety regulations. This alone should convince anyone that micro-inverter is the way to go.

What I have also done is gotten hold of monitoring equipment from OpenenergyMonitor, I got the emonTX, emonGLCD and the Raspberry PI as the base station and boy am I impressed, together all of these monitor my Solar Gen and House Usage, Grid Import/Export, Power Factor, Voltage and basically anything else you want to add and posts everything to the locate DB on the Raspberry PI which can post to a web based system online "emoncms.org" and both are very configurable and have web interfaces Demo Dashboard, I have temperature controllers no their way and with these I'll be installing 2 on the hot water geyser and 2 on my solar water collector, I can them using the same emonTX monitor top and bottom temperatures of the geyser and solar collectors and with a bit of sketch code control the 12V solar pump to ensure at no point am I feeding cooler water into the geyser than what's already in the geyser, it will also give me an idea of the temperature through out the system.  There are also guys doing load diversion with the same systems.

Anyways that's my 2 cents worth.

MJLorton

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Re: Solar Array Install
« Reply #12 on: September 25, 2013, 12:27:34 PM »
Brilliant feedback and update Warlock. Great to hear it first hand and what the micro inverters are doing for you.

Please keep us in the loop with any further updates or challenges with your system. There are loads of folks starting to look at systems like this now and your posts add great value.

Cheers,
Martin.
Play, discover, learn and enjoy! (and don't be scared to make mistakes along the way!)

warlock

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Re: Solar Array Install
« Reply #13 on: September 29, 2013, 01:54:17 AM »
2kW Array Photo Update

SeanB

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Re: Solar Array Install
« Reply #14 on: September 29, 2013, 06:12:01 AM »
Very nice. As you are living in Kloof I would also suggest taking all the metal frames on the roof and connecting them via a 10mm copper cable to a lightning earth, 3 or more earth spikes wired together. Seen way too many dead modems, TV and DSTV sets from there, and have even seen light fittings blown to bits by near strikes.  Ground all the metalwork via a short cable to reduce the build up of charge that can arc over and destroy the equipment. Do the solar water heater case as well while you are at it. Join all the mounting rails to the wire.

I see you cracked a few tiles, better replace them soon or the rain will find a way through and you will be playing at night with buckets and singing a song " Raindrops keep falling on my bed".