Help with solar panel set up...

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DonGould

3892 posts

Uber Geek
+1 received by user: 164

#888404 2-Sep-2013 16:58

webwat: You could run the panels in banks of 48V each, with parallel wiring from each bank of panels to the controller?
12VDC to the modem/router cabinet would be handy... You can get 48V circuit breakers but you want to keep any 12V or 48V (extra low voltage) switching and cabling fully separated from 230V (low voltage).

I found something about an exemption for home owners doing wiring but you would still need a nice sparky to give a safety certificate, probably before gib goes up so they can see the wiring they are signing off on. If you don't get it certified there could be legal problems and the insurance companies would love that -- they get to take your premiums but never ever pay a claim.

Edit: remember battery cabinet needs to be in a ventilated area...

Ok we're starting to talk at cross purpose here.

The unit I linked above is for one site while the original questions were related to another.

While I agree that pointing out regulations is always important to others reading this stuff also give consideration, the points have been made, so we don't need to waste time typing it all time and time again :)

What I'm personally interested in is knowing how to do stuff and how it should be done correctly, no mater who's actually doing it. As pointed out above by one poster, even the registered guys don't seem to get this stuff right.

With respect to owner builders, yes there are many exemptions for building. The guy that owns this building actually had a limited electrical cert, so has a fair idea what need to be done. We've just posted questions around stuff we're not sure on. We also have a number of registered guys who will be checking stuff off and doing final checks etc. I was already well aware of the building cert issues.

As for fires, if readers were aware of the insane fire protection this guy is into then folk really wouldn't have bothered raise issues other than drawing attention to what they now should be done.

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DonGould

3892 posts

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+1 received by user: 164

#892994 10-Sep-2013 23:11

Update for those who are interested...

My first panel purchase arrived this afternoon! I'm excited.

The grid tie converter arrived for the house today as well. I didn't get to see that, but sounds like an interesting product.

Personally I'm only building a little 1 panel 24v system that's completely separate from any 240v power on my house. I'm on a mission to power the growing number of routers living in man cave.

Much discussion has been had about the other building and plans have been changed more than once already. Never fear about the regs and tickets, those convos have been more than had and the right people will be ticking the correct boxes after checking all installations etc... but we are keen to properly understand this stuff too, especially after comments people have made here about experts even not knowing how it's actually meant to be done!!!

D - saving the environment for our kids... one panel at a time!

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garyasta

75 posts

Master Geek
+1 received by user: 4

#894632 12-Sep-2013 09:48

First of all, I have an off-grid system that runs off 1.4kw of panels into a 760ah 24v battery bank.

I would suggest that you take a look at www.aasolar.co.nz

They will help you design your system and provide expert advice on how it should be set up.

Many of the comments that you have received through this forum, are quite relevant, but others are rather "play it by ear" comments.

You should enlist the help of a local electrician who has experience in setting up solar systems.

If you can, I would suggest not using electricity for water and house heating or for cooking. Go gas! Use water solar heating combined with gas and use the batteries, inverted to 240ac, for lighting, frig/freezer, computers, TV, etc.

The 24v battery bank uses fairly standard 6v batteries, possibly in 2 sets of 4x6v units to give the required storage. I use Absorbent Glass Mat (AGM) type batteries over the usual liquid lead/acid batteries. If you can afford it, I would suggest using (or at least taking a look at) the Lithium Yttruim Battery. These are supposed to be longer-lasting and more resilient as far as abuse goes, which is quite likely in the winter due to reduced panel generation.

Trying to use 24v as your main in-house power supply, is not a good idea. The wiring has to be heavier because of the higher current needed to achieve the wattage of appliances, and the actual appliances will all be more expensive and hard to find and service. 240vac is the way to go! Even the lighting is less expensive. LED's are most probably an option as they are now becoming cheaper and use very little power.

Remember when selecting the size of the panels array and the battery storage pack, that you will need at least 50% more than you think you need, to allow for variables. A few too many dark cloudy days will mean that you will need to rely on your diesel generator more than you would prefer.

Good Luck
Gary

L I T H I U M I R O N P H O S P H A T E Y T T R I U M
D E E P C Y C L E B A T T E R I E S

DonGould

3892 posts

Uber Geek
+1 received by user: 164

#894661 12-Sep-2013 10:41

garyasta: First of all, I have an off-grid system that runs off 1.4kw of panels into a 760ah 24v battery bank.

I would suggest that you take a look at www.aasolar.co.nz

They will help you design your system and provide expert advice on how it should be set up.

Many of the comments that you have received through this forum, are quite relevant, but others are rather "play it by ear" comments.

You should enlist the help of a local electrician who has experience in setting up solar systems.

If you can, I would suggest not using electricity for water and house heating or for cooking. Go gas! Use water solar heating combined with gas and use the batteries, inverted to 240ac, for lighting, frig/freezer, computers, TV, etc.

The 24v battery bank uses fairly standard 6v batteries, possibly in 2 sets of 4x6v units to give the required storage. I use Absorbent Glass Mat (AGM) type batteries over the usual liquid lead/acid batteries. If you can afford it, I would suggest using (or at least taking a look at) the Lithium Yttruim Battery. These are supposed to be longer-lasting and more resilient as far as abuse goes, which is quite likely in the winter due to reduced panel generation.

Trying to use 24v as your main in-house power supply, is not a good idea. The wiring has to be heavier because of the higher current needed to achieve the wattage of appliances, and the actual appliances will all be more expensive and hard to find and service. 240vac is the way to go! Even the lighting is less expensive. LED's are most probably an option as they are now becoming cheaper and use very little power.

Remember when selecting the size of the panels array and the battery storage pack, that you will need at least 50% more than you think you need, to allow for variables. A few too many dark cloudy days will mean that you will need to rely on your diesel generator more than you would prefer.

Good Luck
Gary
L I T H I U M I R O N P H O S P H A T E Y T T R I U M
D E E P C Y C L E B A T T E R I E S

Hi Gary,

The solar panel sitting in my office is from AASolar! :)

Batteries are my biggest issue currently.

I'm interested in setting up a low cost concept on a budget. Actually, I've now got about 3 different projects that I'm tinkering with.

I get that cheaper batteries won't last 10 years, but that the same time $1000 just for batteries is also a project killer.

Someone suggested I look at ride on mower batteries.

What I think I'm going to do is take a trip down to the battery shop and just have a good chat with the locals and see what they have to say.

My interest is currently 'on ramp' not 'off grid', though having said that, I did play with the calculator last night and nut out how many panels I could fit on my roof and how much power that might peek at.

Wonder if there's a web site with a list of local sparkies who do solar work by region?

D

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garyasta

75 posts

Master Geek
+1 received by user: 4

#894690 12-Sep-2013 11:35

Hi Don

Batteries should not be a problem if you were tied to the grid. This would be the most flexible and least expensive. Possibly your local body power supplier might be able to help with what a set-up such as this might need.

Depending on the size of an array, you might even be able to make a few bucks out of the input to the local supplier network as long as your night-time needs are less than the excess power generated during the day.

Word-of-mouth may be the only way to get an indication as to local sparkies suitable for helping in your set-up. The local battery bods may be of use here as may any local solar system suppliers.
http://powersmartsolar.co.nz/powersmart_partner_installers
canterburypower.co.nz
http://www.s4solar.co.nz/grid_tie/
http://yellow.co.nz/christchurch/solar-energy-equipment

Ride-on mower batteries and telecom stand-by batteries are a distinct possibility should you need batteries, but these may well be of the liquid lead/acid type needing on-going maintenance. The AGM batteries are maintenance-free.

Cheers
Gary

DonGould

3892 posts

Uber Geek
+1 received by user: 164

#896076 15-Sep-2013 22:13

Hay Gary,

Thanks for the links.

Got my own little system up and running.

Actually seeing a small system going makes so much difference for getting my head around all the issues.

So far I've spent around $800 not including any battery cost by the time I went out and bought some crimpers, lugs and a small inverter to let me pull power off the batteries.

Learning notes so far:

1. Panels come with cool connectors on them... having known that before I started, I would have ordered some to connect up wiring.

2. Sort out your load before you put up your panel! I didn't plan what to do with 190w of power, so once I filled up the battery the panels had nothing to do but float the battery. So I spent a few hours on Saturday morning dashing about collecting up bits to add load.

3. Understand all your bits before you connect them up including indicators and fault conditions. Wife got a fright when the inverter started yelling its head off because the batteries had gone flat. The inverter just shuts down when the battery goes flat, but with a panel on it, in full light, it cycles on and off as the battery gets a bit more juice. I also had no idea what all the indicators on the charger did.

4. Mountings for the roof don't have to cost anything (much). Ended up using some scrap steal, a hand full of tech screws and an hour on the grinder.

5. WAF not high on this stuff.

6. Results are addictive. Seeing is believing and once I got 1 going I started measuring up the roof with visions of covering the whole roof.

7. Rules could be broken?... After I got the first one up, I started thinking what it would take me to run high amp cable down the ceiling so I could get power down to my bedroom to run stuff in there. Then it occurred to me that I don't need to. I can just build another small system at the other end of the building to power my bedroom (radio, TV, Blueray player, side lights, laptop, phone charging). It occurred to me that I don't actually need to build a single large system and push power back into to my existing systems, but it might be more sensible to build small systems closer to where I actually use the power.

8. Fire alarm - calling the alarm guy in the morning is on the list!

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garyasta

75 posts

Master Geek
+1 received by user: 4

#896150 16-Sep-2013 07:55

Good luck on the steep learning curve.

Cheers
Gary

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