TheBackShed.com

Forum Index : Solar : solar panel comparison

Author

Message

grolly

Regular Member

Joined: 19/05/2007
Location: Australia
Posts: 62

Posted: 10:22am 09 Jun 2007

Copy link to clipboard

Print this post

Hi all, which would be the better buy,

4 x 48Volt x 60 W x 1.9 amp, $1996 or

4 x 12Volt x 80 W x 4.8 amp $2760 solar panels

whats more important, wats, amps or volts?

GrollyEdited by grolly 2007-06-11

I have bought the farm...now I AM powering it...

Steve9R

Regular Member

Joined: 24/01/2006
Location: Australia
Posts: 72

Posted: 12:29pm 16 Jun 2007

Copy link to clipboard

Print this post

I reckon.. Efficiency..

48volt systems are a lot more expensive overall to setup,
battery banks / inverters / cabling etc etc = $$,
but are a lot more efficient that 12v systems..

I run 2 x 80w 12v panels for backup linked together to give me 80w @ 24v

all comes down to your budget..

Personally, i'd buy the 12v panels, as you can reconnect them to other configurations if you need to.. (12/24/48)..

SteveEdited by Steve9R 2007-06-17

RossW
Guru

Joined: 25/02/2006
Location: Australia
Posts: 495

Posted: 11:19pm 16 Jun 2007

Copy link to clipboard

Print this post

Small point, Steve....

Two 80W panels in series gives you 160W.
You still have the same *current* as you get from one panel, but twice the voltage.

Steve9R

Regular Member

Joined: 24/01/2006
Location: Australia
Posts: 72

Posted: 09:52am 19 Jun 2007

Copy link to clipboard

Print this post

Yeah.. sorry .. my bad.. not concentrating.. :)

Steve

Prof

Newbie

Joined: 01/12/2005
Location: Australia
Posts: 33

Posted: 03:27am 21 Jun 2007

Copy link to clipboard

Print this post

Hi Grolly,

Your question of "what is important" really depends on what your long term goal is for your system. My aim is to remain off the grid - that is in North Queensland, I am "ERGON free" and I also therefore do not pay ambulance levies. Thus in order of importance is $, warranty, watts, volts, amps.

My approach to buying solar panels starts at the "dollars per watt" consideration. After that warranty is the next consideration. I have a 48 volt system so I have to buy 4 panels (or the equivalent) at a time. If you want a fair dinkum system, 48 volts is good value.

At the present moment the best offer I have seen in Australia is $7.50 per watt for 80 watt panels which have a 2 year warranty on the frame and a 20 year warranty on the rest of the panel. A minimum buy of two panels is needed otherwise the price is $7.90/watt. They can be bought in cities and large regional centres off the shelf.

In answer to your first question "which would be the better buy", I would say that the smaller panels were a better buy on a dollar per watt basis everthing else being equal, but getting a better price on the larger panels may change things someWatt.

Prof

I know boats!!

Trev

Guru

Joined: 15/07/2006
Location: Australia
Posts: 640

Posted: 09:31am 23 Jun 2007

Copy link to clipboard

Print this post

Hi Grolly,

Dollar per watt does count. I don't under stand why the 80w panels are dearer per watt though. Are they the same brand?, same warranty? etc. Most people go for this size. Economies of scale help in keeping the price down. Which panels are better, What voltage do you want?

Choose the voltage. Higher the voltage, better efficiencies, bigger inverter options, smaller cable. How much do you want to run at the same time?

Power = volts x amps. So in theory, 4 x 80w panels in series (4.67 amps at 48 v) is the same as 4 x 8ow panels in parralel (18.68 amps at 12v). They both produce the same power, 320 watts. Work out how much power you need. Most appliances have power consumption in watts/hr on the electrical plate. Multiply this by how many hrs you want it to run. That's how much power you need to produce, by whatever means.

Calculating solar output, use an average of 5 hrs / day of sun. Eg 4 x 80w panels produce 320 watts x 5 hrs should produce 1600 watts or 1.6 Kw / day. No shade and power must have somewhere to go.

Budget? Buy quality. Warranty is a clue but not proof. Ask around for other's opinions on particular products.

Hope this helps in answering 'what is the most important'?

Trev @ drivebynature.com

grolly

Regular Member

Joined: 19/05/2007
Location: Australia
Posts: 62

Posted: 10:36am 03 Jul 2007

Copy link to clipboard

Print this post

Hi Prof, best I have found is $8.62 per watt, BP brand 537x1209 80w x 12v x4.8 amp panels in adelaide, ( $690 each)

latronics 3000w/9000w surge, 24 volt for $2696.00 good price or not??

I have bought the farm...now I AM powering it...

Prof

Newbie

Joined: 01/12/2005
Location: Australia
Posts: 33

Posted: 02:21am 05 Jul 2007

Copy link to clipboard

Print this post

Hi Grolly,

BP panels have a good reputation but they are trading on their name I think. It is difficult to get them at a competitive price. Most of the panels I have are BP.

I have enabled my email address so you could contact me that way if you wish so I can give you some info on how to try getting 80 watt panels for $599 with a 20 year warranty in your area.

I would like to know if what is available to me is also available in Adelaide. I also have a relative in Mt Gambier that imports Chinese panels but I don't know anything about them at the moment. I will try to get some info on them.

Prof

I know boats!!

RonS
Newbie

Joined: 19/06/2007
Location: Australia
Posts: 18

Posted: 01:55am 08 Jul 2007

Copy link to clipboard

Print this post

Hi Grolly! I have had grid-connected solar power for about five years or so and I echo those responders who say that dollars come first, then warranty then watts. I design these systems for others and have done for fifteen years, or so. Also the idea of broadening your options by buying 12v panels is useful if you intend to 'play around' with your panels to try other voltage configurations. My panels are Solarex 120W and they can each be configured as either 12 or 24 volt. In my case 24v since I run them in series-pairs to get a nominal 48volt. The grid connection nets us about $1000+ in the hand each year which pays the rates, etc.

Avoid strong drink. It makes you shoot at tax collectors ...and miss.

grolly

Regular Member

Joined: 19/05/2007
Location: Australia
Posts: 62

Posted: 10:23am 18 Jul 2007

Copy link to clipboard

Print this post

HI Prof,
Sorry I didn't get back to you sooner,far toooo busy at work and with the farm.

Did you get any info on the panels in Mt Gambier, my dad lives there.

as I said above the cheapest I have found are at the BP Solar shop, on prospect rd, their prices for most of their stuff is good, except the batteries, way too dear.

E mail me on geoffr01@optusnet.com.au with your findings

Thanks grolly

I have bought the farm...now I AM powering it...

brucedownunder2
Guru

Joined: 14/09/2005
Location: Australia
Posts: 1548

Posted: 09:45pm 18 Jul 2007

Copy link to clipboard

Print this post

Hello out there,,

If you are connected to the Grid ,,then the Federal Govt. rebate scheme surely must be an incentive.

For 1050 watts you get a reduction of approx $500 per year on todays electricity charges,

6 X 175 watt panels
1 X 1200 watt grid -tie inverter
1 X fully installed system
1 X 20 REC's worth approx $600.

All this for an approx outlay of $4000.minus your $600 if you cash in your REC's(the installer will do that for you,if you like . Plus the installer does all the paperwork,so nothing gets the green light until he gets the rebate approval,you can't lose).

Am I missing something here,as this seeems to be a good deal ??.

Bushboy

petanque don
Senior Member

Joined: 02/08/2006
Location: Australia
Posts: 212

Posted: 02:23am 19 Jul 2007

Copy link to clipboard

Print this post

The quote I received suggested that a 1000w system would produce about 4 Kwh per day this is likely to be dependent on location.

The subsidy from the government certainly makes a solar system more attractive.

If you can get a better return on you money by paying extra off you mortgage would depend on the size of your mortgage and what proportion of your payments is interest.

Also are you likely to be living at the same address in 10 or more years?

AMUN-RA

Senior Member

Joined: 10/03/2007
Location: Australia
Posts: 144

Posted: 04:39am 19 Jul 2007

Copy link to clipboard

Print this post

Don even if you move house the grid system should add more to your resale price than a quick coat of paint and a few flowers in the garden. use it to sell the home and then put the extra cash towards the system for your new houseEdited by AMUN-RA 2007-07-20

Every day the sun shines
& gravity sucks= free energy.

Print this page

To reply to this topic, you need to log in.