Solar panel positioning

[DeeJay]

I've just been up on the roof trying to work out what size system I can fit up there.
There are a couple of questions that would make a big difference.
1/. Can solar panels overhang by, say 50mm over the end of a steel roof?
2/. Or be raised so they go over the top of a ridgeline by a similar space? ( I realize this would allow the wind to get under)
3/. All the photo's I've seen have the panels lengthways vertically along the roof. Can you run some sideways? IE like a "T" or do they lose efficiency?

Hopefully some of you guys have seen this or can help?

Thanks,
David

[bee utey]

There's no good reason why panels need to fit your roof exactly, EXCEPT councils may require separate approval if you alter your building's roof profile. A bit of a cooling breeze under your panels will aid their output. Some panel sets are fitted on angle brackets to lift them off the roof to a totally different angle, no probs so long as your plans are approved. You can mount panels anyway you like, so long as their fastening system allows it. Most fast fit mounting rail kits aren't designed for anything other than fast fit, a small amount of creativity may be needed.

[Jhonno]

I have mine mounted on manually operated tracking poles, one set mounted vertical and two sets mounted horizontal.

DON'T repeat DON'T purchase your panels from LHP on fleabay, I made that mistake for my upgrade set, very poor performance:( compared to the originals puchased in 1992,:D:D they, LHP, seem to have some difficulty in replying to emails and telephone calls.:twisted::twisted:

[superquag]

You only get what you pay for... anything more is a Lotto win...

Main thing is to mount them due NORTH for all-round performance, mine are on 045 degrees (NE) due to roof line. - They start the inverter about 5 to 8 minutes before the sun pokes its head up. :D

Pitch is another debatable aspect (sorry, pun...) Mine are on 18 degrees, same as roof. But putting them up to say, 32 would work against me as the afternoon drop off would be earlier and more pronounced.

A friend of mine with a 1.5 system, has his split between NE and NW. Surpisingly, he's getting a good daily average as its producing useable amounts in the early morning and late afternoon. (Mine nose-dives at around 3:30 pm)

I could get around this by adding a third string, aimed for the winter afternoon sun. (worst condition)

There is NO reason why they cannot be mounted sideways... except "Tradition" . Note that your mounting rails would then need to run vertically, in order to get the approx. 2/5 & 4/5 mounting points on longer sides.

ie, running the mounting rails sideways - as 'normal' - but spaced closer might not be a Good Idea as the panels would be supported on the top/botton ends, with too much length to flap in the breeze...

But running them at right angles (vertically for sideways panels) will increase the labour content...and the Grizzle Quotient from the installers....:mad:

[Vern]

David, whats the roof area you plan to fit them on?. Generally a panel measures approx 808mm x 1560mm (190-200w panels), allow 20mm between panels for clamps and 40mm at either end. Panels can be arranged in either portrait or landscape, (vertical or horizontal), vertically you use less rail to mount them to and can generally get more panels on. Generally you like to have a 'useable area', which is an area where you can still walk around the array (300mm around the edges). Running up ver the ridge is not really a problem, some people don't recommend it due to wind loading, but the framing system is engineered for well over 100klm winds, and if in doubt, more feet can be added.

[DeeJay]

Damien,
I'm looking at Renesola 245w panels 990x 1665 ( made on Suntec assembly line I'm told by the rep, just rebadged) They are supposed to install next Wed but I think they have made the same mistake as a previous company in that they have to fit according to tile spacing & there simply isn't the room. I have a perfect steel roof over the upstairs verandah but it is a 3.3m span & can't be walked on, so all too hard for the installers, so we can only use the house roof which is Tiles.
Company is Solargain..

[Vern]

David,
Suntech make a lot of the cells for different panel manufacturers, i guess its a bit of 'the fish john west rejects', they pick and sell there cells. Some companies buy good cells from them, some buy the lesser quality one. Renesola have a good reputation though, Suntech have a new 200 watt panel out now called 'Pluto', its the same size as the 190w but with better output, they seem to work really well. I have Tianang panels in the shed for my place, these look identical to suntech 190's but are cheaper, been getting really good reviews in the likes of Renew magazine, each panel comes with a test sheet of its performance, majority of the panels are performing slightly above 190w.

Which inverter are you using?

When they come to do your install, make sure you have spare tiles, as they do break. With the brackets they use for the tile mounts, the back of the tile that sits on top of it will need to be ground back to stop the tile from cracking from resting on it, i haven't done one install where the tiles have not needed grinding, i have seen jobs where the tile was not ground and has cracked, causing water damage to the house.
hope it all goes well:)

[DeeJay]

Thanks for the reply, I had the roof resprayed a few years ago, he did a really good job & even offered to spray my spare tiles (I never thought of that !!) fingers crossed, I have 6 spares.
The inverter is a Aurora outdoor 3kw, as one set of 6 panels ( 245 watt) is facing NNE & the other 6 facing NNW, give or take. If they say they can only fit 5 each roof section I'm going to crack it, as I'm already cranky they are'nt interested in the sun deck roof which can fit another 5 panels, OK it needs spreaders to walk on, but was put in the too hard basket pretty rapidly...:(

[Vern]

Anything is possible, but as the aurora only has 2 seperate inputs, then nne and nnw will use them up. I have a 6kw aurora for my place (yet to get it up and running (time)), they are a great inverter, a little noisier, but still a really good performer, SMA would be my #1 choice, then Aurora #2, but they are that close in perfomance levels, its non debatable.
If you were to use the sun deck, then you would need a bigger inverter, and need to series/parrallel 2 of the strings.

[DeeJay]

The inverter subject could be another way of edging money out of me ( skeptic aint I :D) as we started with a SMA & then the rep rang me with "good news" as they could utilise an Aurora. I kinda said we agreed on a unit & why change & he said he was just trying to save me a couple of hundred $$. My Scottish heritage came into play & I agreed. From the paperwork that later arrived it is nearer to $90.00:(.

Cheers, David

[Vern]

Depending on what size the inverter is, 5kw SMA are unavailable at the moment, all the ones being made are being sold through out Germany first, not sure if this is the case with the smaller units.
Majority of salesman/agents in this field are liars, they all have the 'best' system, research what they are selling you first. The Aurora is a good unit:)

[superquag]

Be aware that many "German Manufactured" inverters have their circuit-boards built etc in CHINA. They are then sent to Germany, to be installed in German-built (?) boxes.
Some boards are built it Taiwan. - A wholesaler I got chatting with was more than happy to spill the beans, named them and showed me a couple in his back-store. (I was chasing up Solar Hot water systems.) His advice was to buy on features/performance, and not to pay heaps more just because of a "Made" in Germany sticker.

- Nothing intrinsically wrong with them, just a point for the sales-Liars to be challenged on...:twisted:

The other thing to watch, is the quality of the panels, and their 'tolerance'. I paid more for my REC brand, could have had the AstroEnergy for much less, but the REC's were described as xxx watts, -0 to +5% tolerance. The Astro's were something like +/- 10%.
Point there is, my panels have sometimes put out way more Watts than they should in theory... and compared to a couple of AstroEnergy systems on trackers, the extra $$$ are paying off. - Mine produce closer to their 'rated' output despite being on 18 degress pitch and facing NE. In short, my $$$$ panels outperform the cheaper ones on a full-monty tracker, Both systems run the same brand/family of inverters, Motech.

My 5 cents worth :p

[DeeJay]

Well the installers rocked up today, - rained out last Wednesday- & I got them up on the roof to measure first & sure enough, not enough room for the unit they brought out:(
So it looks like instead of the 12 x 250w panels I needed, it might go to 10 ( they think maybe less) or 14x 190w panels ( they can put them side on they say) or go for the 318w panels & pay a (lot) more. I suspect I wont hear from them again as they grumbled a fair bit about access plus the Sales person who made the committment is "no longer employed by us"
In fairness, the Sales Manager appears to be very helpfull and has been put in this position by a rogue salesman. The price went from $6914 to $6419 based on a different inverter & a $300.00 reduction for the inconvenience - but this was on Friday, so I figure he forsaw this happening.
So now they have to get back to me with pricing & options, now they have measured the roof.

[Vern]

David, why not 14x200watt suntech Pluto's, they are the same size as the 190watt., so you will get 2.8kw vinstead of 2.66kw:)

[DeeJay]

Just an update, they got back to me shortly after my last post & are coming out on the 16th with 15x 190w Hanwa panels & the same Aurora Inverter & keeping the price at $6419.
That sounds pretty fair to me.
I also think it hits the sweet spot, all things considered..

[blitz]

Your question regarding can they over hang the edge of the roof. No, at least not anywhere in Qld

Angle of the panel is determined by your Latitude, the further south you are the greater the angle. But it's not guess work this is why by law only electricians with the cert IV photovoltaic qual are allowed to install them. Unless the total voltage is below 120VDC and stand alone not connected to mains supply

From memory the unit which explains about angle is UEENEEK035B design grid connected power supply systems

It is a science not guess work, but having said that google is you friend

Good luck with it

Blythe

[DeeJay]

Well they got installed during the week & finished off Sat Morning.:cool:

N/East side

https://www.aulro.com/afvb/images/imported/2012/05/463.jpg

N/West side

https://www.aulro.com/afvb/images/imported/2012/05/464.jpg

Inverter

https://www.aulro.com/afvb/images/imported/2012/05/465.jpg


Hopefully they can simply push a button to initiate to the meter, the installer was a bit vague, he says some do, others need upgrading to smart meters & I really don't want one of them. This fairly new anyway.

https://www.aulro.com/afvb/images/imported/2012/05/466.jpg


So now we wait on the Electrical inspector & he sends off the connection request to AGL. They say could be 6 weeks before feeding back in to the grid ( not to optimistic about that one).

[isuzurover]

So - Deejay, You have half your panels facing NW and the other half facing NE?

We had our solar installer come out today. I mentioned going half/half as we also have NE & NW facing roofs. He said I would need a (much more expensive) dual inverter???

Sounded like BS to me??? - I am sure it is cheaper for them to install them all in one spot.

[rovercare]

So - Deejay, You have half your panels facing NW and the other half facing NE?

We had our solar installer come out today. I mentioned going half/half as we also have NE & NW facing roofs. He said I would need a (much more expensive) dual inverter???

Sounded like BS to me??? - I am sure it is cheaper for them to install them all in one spot.

That will be why he has an aurora, dual mppt, as running 2 strings at differing azimuth will not work well at all, they are correct

[isuzurover]

That will be why he has an aurora, dual mppt, as running 2 strings at differing azimuth will not work well at all, they are correct

OK, cheers. Good to know he wasn't feeding me a line...

So why is that the case electrically?

I suppose I will wait until the inverter dies, then switch to a dual mppt and add more panels on the NE facing roof.

[rovercare]

OK, cheers. Good to know he wasn't feeding me a line...

So why is that the case electrically?

I suppose I will wait until the inverter dies, then switch to a dual mppt and add more panels on the NE facing roof.

Loosely, when you have two different strings(rows of panels on series) that get sun at different times, the one with sun wants to turn the other into a heater, they need to be matched both electrically and position, azimuth and inclination, unless on a dual mppt inverter

Trying to obtain anything other than bulk yield varies state to state as it depends on your feed in tariff, if you receive wholesale price, 8ish cents/kwhr it makes sense to match your usage, but if you receive a good tariff, best to aim for bulk yield, concentrate on peak sun hours. All varies with location/shading/mounting/cost

[isuzurover]

Loosely, when you have two different strings(rows of panels on series) that get sun at different times, the one with sun wants to turn the other into a heater, they need to be matched both electrically and position, azimuth and inclination, unless on a dual mppt inverter

Trying to obtain anything other than bulk yield varies state to state as it depends on your feed in tariff, if you receive wholesale price, 8ish cents/kwhr it makes sense to match your usage, but if you receive a good tariff, best to aim for bulk yield, concentrate on peak sun hours. All varies with location/shading/mounting/cost

Cheers. Unfortunately I missed the boat on 49c/kWh in WA. It is now down to 7c/kWh...

[rovercare]

Cheers. Unfortunately I missed the boat on 49c/kWh in WA. It is now down to 7c/kWh...

Best to match usage then, might have to lash on a dual mppt inverter!

Been looking into stand alone viability, a dude who has been subcontracting for me is hoping to play with a setup, just need to get the return of investment down to something reasonable

[Vern]

Finished a stand alone today for Ross, 14 panels, 2 in series, 7 in parallel, 3kw Latronics 24v inverter, 60a reg, with 8x 6v 535 a/h batteries, 1070A/h. (4 in series then parallel) Seems to work ok so far, its got me thinking to now:(. Alot more wiring though:(.
In Dollar if ya want a looksy:)

[DeeJay]

The inspector came out Saturday morning & turned everything on, 19KW generated so far.
Then our "electricity provider" rang today & this is the deal- no names, no pack drill :angel:

We currently pay 22.671 cents/kw flat rate 24/7 - less 12% due to contract.
plus 88.385 cents service charge a day.

For Solar connection they want...
$44.21 to configure the meter plus a $49.14 fee if access is difficult- but otherwise refunded.

Then the rates go to
Peak 3pm to 11pm 35.5 cents/kw
Shoulder 7am to 3pm 25.27 cents/kw ( not certain of the decimals but thats what I wrote)
Off peak "all other times" - ie 11pm to 7am 11.73 cents/ kw

96.91 cents per day service fee

BUT - I get to keep my "advantage 12" discount.

Now this was said to me by an Indian guy with associated accent- no make that prattled & I said whoa up, I need to write this down ( much to his annoyance) and he immediately pressed me for a commitment & put on the surprised reaction at me when I said I needed to think about it. That got me going & I said we would not be having this discussion if they had these figures on thier website, when pressed he said that they are on the Origin site ( which is another company)

I'm not regretting going Solar, most, probably 80% will go to internal use anyway as we use 25kw/day & I now have told the missus to try to do the ironing, washing, vacuuming etc during the day, & one at a time if not sunny:D
But I've asked for a copy of our agreement to be emailed :twisted:

[Vern]

your not with Lumo are you? Whatever the case i have whether it bew solar, basic truck appoointments, Lumo are the most useless company i've ever dealt with. I did a job with them that took 6 months for a basic truck appointment, this normally takes 3-4 weeks.

[DeeJay]

Vern,
Not with Lumo, AGL.
David

[rovercare]

Vern,
Not with Lumo, AGL.
David

Not much better, still waiting after 4 weeks on a truck appointment for a meter panel upgrade

I was talking with a dude in nsw, I'm doing a 7kw install for, they do nation wide solar, he said Vic retailers are the worst nation wide, by a very large margin:(

[Vern]

7 kw in Yinnar? They rang me to if it is, said ok send me the info, never got it. no biggy:)

[rovercare]

7 kw in Yinnar? They rang me to if it is, said ok send me the info, never got it. no biggy:)

Their rates were average, after amendments it'll be a 2.5k profit for a big day after overheads

[Vern]

Good coin, main thing is they pay and are good to deal with. Whilst the money is good, doing it full time would drive me nuts.

[rovercare]

Good coin, main thing is they pay and are good to deal with. Whilst the money is good, doing it full time would drive me nuts.

I average over 1k a day when off normal shift, that's after overheads of subcontractor and 2 workers and they are paid well and promptly, I'd do it every day, relatively stress free

[Vern]

I more meant it would get boring. I like the variety of different jobs, it helps with my disturbed little brain;)

[DeeJay]

Just an update on this installation.
It has generated 1163 Kw in just under 5 ( winter) months
Fed in 483 of that back to the grid.
Therefore I've used 680 kw saving 19.9 cents per KW = $135.32
Fed back in 483kw @ 33 cents per KW = $159.06
repaid to date $294.38

Assuming that the summer will be 30% more generation I would think that could go another $400 which is around &700 payback on $6400 in the first 12 months. Not lucrative but better than a lot of investments ..

[TerryO]

Plus it means less coal is burnt which has to be a Good thing all round even for some one like me who is not a Greenie.

Actually that is a good return on investment so even better.

cheers,
Terry

[rovercare]

Plus it means less coal is burnt which has to be a Good thing all round even for some one like me who is not a Greenie.

Actually that is a good return on investment so even better.

cheers,
Terry

Yep, shutting down generators everywhere, and that silicon was melted down in fossil fuel free fired burners in china:D

[isuzurover]

Yep, shutting down generators everywhere, and that silicon was melted down in fossil fuel free fired burners in china:D

A guy a Murdoch uni did a thesis looking at energy and carbon payback periods from grid interactive solar systems in AU. Melbourne/vic was the quickest (0.8 yrs) - even though they don't have as much sun as elsewhere - because they burn brown mud (as you would know). Tas was the longest - 1.3 years. Others were in between.

The study factored in the emissions during production in US/EU/China and transport. All the aluminium in the framing and the inverter ended up being as bad as the silicon (or worse).

[rovercare]

A guy a Murdoch uni did a thesis looking at energy and carbon payback periods from grid interactive solar systems in AU. Melbourne/vic was the quickest (0.8 yrs) - even though they don't have as much sun as elsewhere - because they burn brown mud (as you would know). Tas was the longest - 1.3 years. Others were in between.

The study factored in the emissions during production in US/EU/China and transport. All the aluminium in the framing and the inverter ended up being as bad as the silicon (or worse).

Impressive, Tas is interesting though, as its primarily hydro, aside from the basslink interconnector and I think Launceston power station, linking it to the eastern seaboard of the big island, so I wonder where there large carbon emmissions come from?

I think there may be more "interesting" data which may skew the outcome, also depends on the source

Essentially it has done alot for A/C peak load, as this is a major problem, although its had a few negative effects in vic, with feeder set ups and the assosciated antiquated voltage reg's, auto tap tranny's working overtime, so there is more moola in infrastructure to make up for

Although, in sunny QLD they can oversize there systems as opposed to mexico being restricted to inverter size, would be interesting to know the after effects, although, there grid may of been better to start with, I have no idea