# Forum Home Renovation Solar Electrical Systems  Anyone know about solar panels?

## Wombat2

Origin have a promo on at the moment and I'm looking at putting in a system and confused with the offerings.  
The base model (1.5KWatt) has the most efficient panels (monocrystal=14.24%) but a non upgradable inverter  
the next two models (1.6 and 2.0 KWatt) up have upgradable inverters but less efficient panels (polycrystal=12.84%)  
The upgradable can have another unit plugged into it to double its capacity - second unit only cuts in when needed. 
What to do?

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## SilentButDeadly

Bear in mind that mono and poly panels are different in size for a given wattage.....and poly are typically smaller than mono.....so you can fit more.  Go with one of the upgradeable inverters. 
Check out Rainbow Power Company. for lots of useful solar info

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## Smurf

Panel efficiency is unimportant for a typical grid-connected situation unless you have limited roof space and will be installing as many panels as can physically fit on the roof - in which case you want the most efficient since they will have a higher output for a given area used. 
Sunlight isn't like petrol or coal. The latter are limited resources and polluting in their use, hence it makes sense to use them as efficiently as possible so as to reduce the amount needed for a given application. But there's no consequence to wasting sunlight - having less efficient panels isn't going to cause the sun to run out...  :Biggrin:  
So as I said, if there is an issue with roof space then you want high efficiency. If that's not an issue then efficiency becomes pretty much irrelevant - what you need to worry about is power output versus $ spent. :Smilie:  
I see from the Origin website that they are charging $2990 for the 1.5kW system but I can't see a price for the larger systems. What is the price for those systems? Also, what is the brand of panels and inverter used? 
If you can post details of your roof pitch (angle from horizontal eg 22 degrees) and how far from North your roof faces (eg 20 degrees west of North) then I'll put the numbers into the software I have and tell you how much power you can expect to produce. 
Disclosure: I own shares in Origin. As with most things, you should get several quotes from competing suppliers before making a purchase. (My own solar panels were supplied and installed by Nu Energy).

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## Bloss

:What he said:  - efficiency is pretty much irrelevant for a comparison for most home systems. An upgradeable inverter can mean a number of things - it can simply be an inverter with a larger capacity than you need now and the ability to cater for added panels - on the same roof or with exactly the same solar orientation. If you are thinking of adding panels later on a different roof and orientation then often the system designer will commonly use two inverters, but some inverters can cope with that situation. 
Usually best to simply have the system designed for what you need and can afford now and then do the same for the upgrade. The comparison between systems that has most meaning is estimated output for the proposed system in kWh annually at your location. Most quotes should show that and show what happens with different brands and models of panels and inverters. The one that gives you the most output at the least cost is the one to go for - and a company that you can trust (ie: large and been around for a while - or better one that has installed systems like yours and you can talk to the owners about what they think).  :2thumbsup:  
Worth getting an inverter with 10years warranty not 5 too.

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## Wombat2

Panels are "Sharp" Base (1.5Kw) inverter is Sharp - The bigger ones are Fronius 
Our roof is a V shape one side faces NNE the other NNW in other words basically facing North. there is a total of 36 sq m of 7 degree pitch and 28 sq m of 25 degrees - No shade falls on the roof.  Latitude is -26.4 degrees 
The 1.5Kw = 15 sq m of panels - 1.6Kw = 16 sq m and the 2Kw = 18 sq m 
prices are $2999, $7190 and $8490 respectively ( dearer ones may be cheaper as the 1.5 Kw is normally $3999)

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## murray44

Hi Headpin, 
What's the signifcance of the July installation date? Is that when a rebate expires or something? 
Just started looking but might have left my run a bit late  :Redface:  
Murray

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## Bloss

> Hi Headpin, 
> What's the signifcance of the July installation date? Is that when a rebate expires or something? 
> Just started looking but might have left my run a bit late  
> Murray

  Murray - probably too late to get the 50.5c FiT in Canberra as you'd need to get that in and all certified by 30 June (and that will be near impossible - due to Actew & ACTPLA delays), but the only change will be a FiT of 45.7 kWh (and a 20 year contract!) after that so go for it ASAP. The Fed subsidy is through RECs which will be fixed at $40 after 1 July for small generating systems. 
See here for federal support info Department of Climate Change and Energy Efficiency - Small scale renewable energy systems under the RET scheme and here for ACT: http://www.environment.act.gov.au/__...TFactSheet.pdf and here: ActewAGL : Environment : Solar : ACT government's Feed-in Tariff and here: ActewAGL : Environment : Solar : Installing solar panels in your home or office and here: ActewAGL : Environment : Residential Solar Step by Step Guide 
This varies state by state.

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## Bros

> For those of you interetsed. I went with the Energy retailer, Origin and a 1.5 KW system manufactured in Japan by Sharp.

  Maybe not as I understand Sharp has now started manufacturing in China.

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## Wombat2

> Maybe not as I understand Sharp has now started manufacturing in China.

  They do have a "25 year warranty" - but having read the fine print it may be difficult/costly to claim. It comes as 1 year 10 year and 25 years 
1 year plain not working/materials etc 
10 year less than 90% output and 25 years less than 80% of output - owner responsible to remove transport insure and reinstall

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## Bloss

> They do have a "25 year warranty" - but having read the fine print it may be difficult/costly to claim. It comes as 1 year 10 year and 25 years 
> 1 year plain not working/materials etc 
> 10 year less than 90% output and 25 years less than 80% of output - owner responsible to remove transport insure and reinstall

  Same as all panels - 25 years - but not the inverter. Panels most likely to actually last 40years, but to be recycled within 20 or so and replaced with much better technology! In ACT & NSW payback is under 6 years due to gross feed-in tariff (FiT). The main thing is if they go kaputt within a few years (as they are more likely to) to be able to go the retailer 1st and manufacturer or distributor next if anything goes wrong. Make sure that all serial numbers are recorded (on each panel and the inverter) and given to you along with all the install details required by the manufacturer (they are mostly on there web sites. 
The 1 year 'plain not working' is rubbish - that's what they might claim, but your statutory rights under the Trade Practices Act gives you a better cover than that - based on what can reasonably be expected for the goods concerned. Those rights also mean they can't simply say to you that you have to return it to them at your cost whatever they write in the warranty document. 
But once you get the system paid off then the real issue is how much you can get for the power you produce each year - and regardless of a FiT energy prices will go up so the worst result is that your system provides you with a good discount on the power you use. In the ACT you will make a good income each year after payback and in NSW you will have up to 7 years (well nearer 6 now) to get payback and some income - then whatever you can sell your power for.

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## murray44

Headpin and Bloss, 
Thanks for the replies. Thanks for all the links too. 
Murray

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## Bros

> The supplier did say they were manufactured in Japan, the packaging also said "product of Japan".   
> In todays world that probably means sweet FA .......who knows?

  If it says product of Japan it would be OK as Sharp will have to disclose where it comes from. 
I saw a heap of them last week at the Solar installer I know when I was getting a warranty claim on an 80w panel of mine that turned up its toes after 9 mths.

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## Smurf

> Panels are "Sharp" Base (1.5Kw) inverter is Sharp - The bigger ones are Fronius 
> Our roof is a V shape one side faces NNE the other NNW in other words basically facing North. there is a total of 36 sq m of 7 degree pitch and 28 sq m of 25 degrees - No shade falls on the roof. Latitude is -26.4 degrees 
> The 1.5Kw = 15 sq m of panels - 1.6Kw = 16 sq m and the 2Kw = 18 sq m 
> prices are $2999, $7190 and $8490 respectively ( dearer ones may be cheaper as the 1.5 Kw is normally $3999)

  On the basis of those prices I would go for the 1.5kW system. 
If you installed the 2kW then you are paying $5500 for that extra 0.5kW which just doesn't stack up financially given that, depending on location and what price you get for power produced, it's only going to produce $120 - $400 a year worth of extra power above what the 1.5kW system would produce. That's not really a great investment on that last 0.5kW. 
I'd install the 1.5kW now unless you really do have the $ and want a bigger system. That's simply on the financial basis that the extra cost for the larger system isn't really worth it. Of course, if you're not worried about cost then that's another matter - get as many panels as you can fit on the roof.  
For a 1.5kW system and assuming it's on a NNW facing roof (30 degrees from North) then the following figures are what the software comes up with for a 1.53kW system using one of the more common (in Australia) Chinese panel brands. 
Mono panels, 7 degree pitch = 2119 kWh per annum
Poly panels, 7 degree pitch = 2124 kWh per annum
Mono panels, 25 degree pitch = 2167 kWh
Poly panels, 25 degree pitch = 2173 kWh 
So all much the same. Don't worry about Mono versus Poly panels etc, just make sure it's a decent company using decent equipment, warranty, price etc. Those figures are for AC output from the inverter - losses etc have already been deducted. Note that I used Brisbane as the location of the installation. 
Correct pitch is something that many people get wrong since there are multiple "correct" answers depending on what you are hoping to achieve. Generally speaking, if you want maximum annual output then that means maximising output in Summer and not worrying about what happens over Winter since the days are shorter then anyway. But for a stand-alone system that isn't going to work and in that case you want either maximum Winter output or some compromise arrangement that will be further complicated if there is seasonal variation in energy use. But even in a climate such as Tasmania, you can get pretty decent output during Winter (at the expense of total annual output being lower) with a sufficiently steep pitch. 
But all that said, in your case just put them on the roof and don't worry about the pitch. Given the location and pitch of your roof, there isn't much to be gained through messing about with that. 
As for how much the power produced is actually worth in $, you'll need to ask your electricity retailer since rates vary hugely across the country. :Smilie:

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## Wombat2

Thanks everyone for your input - I rang Origin to get more details and discovered I'm up for another $1000 because I am beyond 100 Km from the GPO - (110)  :Mad:  
I've noted some local installers offering similar deals so I've got some coming to give me quotes before I goback to Origin and see if I can twist some arms  :Wink 1:  
Edit - just worked out the "100Km" is based on Post Codes - we are 1.5 km over the post code boundary - That is a pricey 1.5 Kms

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## Nifty1

Just watch that feed-in tariff deal. TRUenergy in Vic apparently pay 66c FIT BUT they no longer let you have off-peak rate for HWS! In my case it would cost me more to accept the FIT so I just watch the meter spin backwards from time to time. It's a dud deal if you ask me, and no way to encourage us to assist fighting the greatest moral challenge of our time!

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## Wombat2

Found some other deals with better prices and better explanation of sizing. Current offer is 1.6Kw @ $3290, 2Kw @ $7425 and 3.0Kw @ $12790 (after RECS) 
Big question - Why can't I have 2 1.6Kw systems for a total of $6580 instead of the 3.0 @ $12790 ???? Anyone know if there is a problem feeding two inverters into the grid at the same location? 
Edit :Redface:  been told I won't get the RECs on the second unit - even so the 2 x 1.6 is still just over $700 cheaper then the 3.0 Kw unit

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## peter321

> Found some other deals with better prices and better explanation of sizing. Current offer is 1.6Kw @ $3290, 2Kw @ $7425 and 3.0Kw @ $12790 (after RECS) 
> Big question - Why can't I have 2 1.6Kw systems for a total of $6580 instead of the 3.0 @ $12790 ????

  The reason why the 1.6KW is the price it is is because of the Gov. rebate, Recs etc, and you only get that rebate once....  to get 2 x 1.6kw systems for $6580 you would need to get 2 complete rebates.  
When you look at the price of solar gear before any rebates / recs you get a better picture of what things are really worth.

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## Smurf

Government policy is the reason for the price difference as others have said. 
Technically however, there's no reason why you can't have multiple inverters at the one location. They are ultimately just tiny power stations feeding into the system as do large coal / gas / hydro power stations, most of which have multiple generating units. As long as your wiring is done suitably, no problem with multiple inverters (or any other kind of generating plant) at the one location.  
All that said, a word of warning. If you're going to install 1 or 2kW then no problem. But if you installed 100kW then limitations on the local distribution network will become a problem and will need fixing (quite possibly at your expense). But in that case you'd be building a small power station, not just putting a few panels on your roof...

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## Wombat2

Have been shopping around and prices have dropped considerably in the last couple of days. Ingenero are offering a 3Kw unit for $12790 after RECs - which, after doing my sums and the savings etc etc we have decided to go with. 
Planning to introduce some other efficiencies like solar panels for the hot water (I can make my own - we are on tank water and I have made them before) also will replace all our 50watt downlights with LEDs

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## eighty-eight

I don't mean to brag but with a 16 panel system from solar shop on my roof, power is now about $10 a month. Best investment ever.

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## Bloss

> All that said, a word of warning. If you're going to install 1 or 2kW then no problem. But if you installed 100kW then limitations on the local distribution network will become a problem and will need fixing (quite possibly at your expense). But in that case you'd be building a small power station, not just putting a few panels on your roof...

  Not so - depends very much where you are and the state of the grid/ network where you are located. Most networks can cope with a 20% of total network capacity feeding back into the grid - the local utilities will know what the situation is. It's not a concern for the householder seeking a FiT as no scheme pays a FiT above 30kW and that is well able to be coped with in most towns & cities (and few will have roof top large enough to install 30kW(130-150 panels!). Some regional rural sites you would check (and any reputable installer will know anyway) on local restrictions if there are any. And unless you are on a rural block individual homeowners are not responsible for the grid upgrade costs. The electricity retailers will all tell what you can and can't do with their existing infrastructure and when any upgrade might be planned.

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## president_ltd

> I don't mean to brag but with a 16 panel system from solar shop on my roof, power is now about $10 a month. Best investment ever.

  why stop at 16 panels when you can end up having them pay you?  :Biggrin:  
just had this installed this week... tickled pink by it.  :Biggrin:   
Climbed up on the roof really to see if there was any  cracked tiles that needed to be replaced etc. Pictures ended  up being a bit close to the panels and it was difficult to get a "from a  distance" picture of it, but these should give you the idea. 
First   up, the inverter itself.  DC and AC isolation breakers on the left hand  side.  Inverter is powered on here but no DC side connected.
awaiting inspection before going into "production":   
Next is the first string of 9 panels.  These go into a single input.   This is almost precisely north facing roof over carport.  Tree in  background likely to be removed but not really a problem at the moment:   
Next is the second string of 9 panels which is in series with a 3rd  string.  Again an almost exactly north facing roof, roof pitch is around  30 degrees.  Feijoa tree will need a bit of haircut (but not much):   
3rd string which is in parallel with the 2nd.
again, this is 9  panels.  again, almost exactly north facing:  
So in summary 27 panels, 180W/panel, just under 5KW total.  at peak  will generate ~5KWh in full sunlight in ideal conditions.  average will  be less than that since its not sunlight 24 hrs/day and its not clear  sunlight all the time and ambient temperature will impact efficiency  too. 
but net-net should be that our current annual "average" power consumption of  ~17-18KWh/day will be met with the panels and then some.

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## Wombat2

Nice system Mr President.  Who did you go with? I would like a 5Kw system but could not quite justify it so will stick with the 3. The swimming pool pump is the biggest user of power in our place ( 2KwH - for 4-8 hours a day depending on the season) _ I am having  it put onto night tariff the same as the hot water at least that will drop the cost from 36 cents an hour to 14 cents on current prices  but Queensland is having a 16% price hike 1st July - bet the feed in tariff won't go up

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## president_ltd

> Nice system Mr President.  Who did you go with?

  Energy Matters.  Solar power : grid connect, off grid and hot water systems, solar panels, batteries, wind turbines - Energy Matters Australia   

> I would like a 5Kw system but could not quite justify it so will stick with the 3. The swimming pool pump is the biggest user of power in our place ( 2KwH - for 4-8 hours a day depending on the season) _ I am having  it put onto night tariff the same as the hot water at least that will drop the cost from 36 cents an hour to 14 cents on current prices  but Queensland is having a 16% price hike 1st July - bet the feed in tariff won't go up

  why does your pool pump draw 2KW?  seems way over-sized. 
have a pool here, ~60,000L size, pump is a 3/4HP. draws about 450W when on.

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## Wombat2

> Energy Matters.  Solar power : grid connect, off grid and hot water systems, solar panels, batteries, wind turbines - Energy Matters Australia   
> why does your pool pump draw 2KW?  seems way over-sized. 
> have a pool here, ~60,000L size, pump is a 3/4HP. draws about 450W when on.

  2KwH - 2 HP pump (72000 Litre) = 1540watts but the power meter shows it consuming 36 cents an hour so the chlorinator must be pulling some power as well. Pump was sized to turn the water over in a shorter time - smaller pump would have to run longer to move the same volume as a bigger pump. 3/4 HP would pull 577 watts thereabouts.

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## barney118

Some good info comming out here, in simple terms I dont understand the measurements here, What does a 1.5Kw system produce, I take it is 1.5kw per hr when the sun is up. Given I use 15-20 Kw per day I am trying to get an understanding of how long it would take for payback on a system. Also my house faces Nth but I have limted roof space and would have to put in on the east side of my roof (21 deg), given I have Mountains in the West and might get more sun in the morning.
Ultimately I havent heard of such a system that could incorporate solar heating for my pool which I dont have yet and they will be competing for roof space, is there such a system?
The latest I have heard too is the sneaky govt are looking at taxing you for the income earnt in the FiT, what a bloody joke.

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## nww1969

Looking at presidents pic's I noticed the brackets into the roof to the rafters keep
the tile lifted and was wondering if anyone has any problems with water leakage from
the bracket. 
Almost had mine installed last week but the rain came as soon as they slid  the 
first tile back, now at the back of the que and as others have mentioned deadline
is approaching 6th July

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## president_ltd

> Looking at presidents pic's I noticed the brackets into the roof to the rafters keep
> the tile lifted and was wondering if anyone has any problems with water leakage from
> the bracket.

  where you can see the tile slightly lifted, its maybe about 4mm lifted  (at most), and the tile is overlapped 50% on the tile (probably ~100mm),  so its not really any issue.
all that the slight lifting of the tile where the bracket means is the  angle of that tile is slightly less.
could be an issue if it was a low roof pitch i guess. 
regardless, i did wonder about that, so i went up in the roof with a torch over the last few days while its been raining in Melbourne.  no water coming in, even though we had quite a big downpour, so all good.   

> Almost had mine installed last week but the rain came as soon as they slid  the 
> first tile back, now at the back of the que and as others have mentioned deadline
> is approaching 6th July

  hmm, if they 'started' the install they should have come straight back to do it.
it was lightly raining here while they were doing it, even when there was slightly more rain (downpours) they just did some of the other work instead, e.g. the laying of DC cables, inverter/switchboard work etc. 
if your $$$ is tied to the $8000 rebate i'd be pressuring them to give you a fixed install time. 
our system wasn't part of above rebate but i still made it conditional on them installing in a prompt manner. 
love that on a day like today in Mebourne (cold, wet and sunny at times), its telling me for 5KW of panels its up around 4.3KWh generation when the sun is out, even when its behind cloud its still >2KWh.
while its not been generating enough to negate our power consumption, its about 2 weeks away from winter solstace so its almost as bad as it gets at the moment and will all be upside soon.

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## MiniSkips

Here is a great solar panel resource Solar Energy, Wind Energy & Renewable Energy Products

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## Smurf

> Some good info comming out here, in simple terms I dont understand the measurements here, What does a 1.5Kw system produce, I take it is 1.5kw per hr when the sun is up. Given I use 15-20 Kw per day I am trying to get an understanding of how long it would take for payback on a system. Also my house faces Nth but I have limted roof space and would have to put in on the east side of my roof (21 deg), given I have Mountains in the West and might get more sun in the morning.
> Ultimately I havent heard of such a system that could incorporate solar heating for my pool which I dont have yet and they will be competing for roof space, is there such a system?
> The latest I have heard too is the sneaky govt are looking at taxing you for the income earnt in the FiT, what a bloody joke.

  Expect somewhere around 1500 kWh per year for a 1.0 kW system in NSW. Closer to 1200 kWh in Tasmania, heading toward 1800 kWh in Queensland / NT. 
Those figures scale - so a 1.5 kW system produces 1.5 times as much as a 1.0 etc. 
These panels produce electricity, not heat. Producing heat for household hot water requires either flat plate or evacuated tube collectors which are entirely different to PV (photovoltaic) panels which produce electricity. Heating for pools usually uses low tech black piping to simply extract heat from the roof - cheap and good enough given that you don't need (or want) to boil the pool.  
These are all separate systems, but there are some companies that are involved with all of them (eg they offer a combined solar HWS and PV deal at a discount if purchased at the same time). And of course they are all competing for the same roof space, potentially an issue if your roof area is limited.

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## Bloss

Confusing ain't it! 
kW (kilowatt) = the measure of capacity or size of a generator. 
kWh (kilowatt hour = the amount of power output generated (or used – that’s how we are billed) over one hour (that is: the size or capacity multiplied by hours of operation from the renewable power source by wind, solar, wave etc). 
A 1kW PV system nominally produces 1000 Watts each hour, a 1.5kW system 1500W each hour – often shown as kWp. That is so long as light is shining on them. But inefficiencies, mainly the impact of heat on cell performance, mean the real output will be around 20% less. 
In Canberra the average daily hours of sunlight is around 7 so a 1kW system would produce ~4.8kWh per day or ~1750kW annually on average (more in summer, less in winter). The attached file shows roughly what you can expect from a 1kW system in Oz capitals. These are conservative estimates.

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## chrisp

> Confusing ain't it! 
> kW (kilowatt) = the measure of capacity or size of a generator. 
> kWh (kilowatt hour = the amount of power output generated (or used – that’s how we are billed) over one hour (that is: the size or capacity multiplied by hours of operation from the renewable power source by wind, solar, wave etc).  *A 1kW PV system nominally produces 1000 Watts each hour, a 1.5kW system 1500W each hour*

  *I'll say it is confusing!* 
The panels produce *energy*.  The unit of energy is *Joule* (J).  The *rate* that the *energy* is produced is *power* (Watts, W).  1 Joule/second (J/s) = 1 Watt. 
Where the confusion arises is that electricity is billed as *energy*, but the unit isn't *Joule* (or Mega Joules), but *kiloWatt-hour* (kWh) pronounced "kilo  Watt  hours".  Note, the product or multiplication - is is not a division or "per" unit (i.e. it is *not* "kiloWatt per hour"). 
1 kiloWatt (kW) = 1000 Joules per second (J/sec) 
1 kWh = 1000 J/s x 1 hour= 1000 J/s x 3600 seconds
= 1000 J/[s]s[/s] x 3600 [s]seconds[/s]   (striking out the 'seconds' in the numerator and the denominator)
= 3,600,000 J
= 3.6 MJ

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## Bloss

All fine, but that's being unnecessarily complicated - just makes it harder to understand for most people IMO. My post was trying to link to how charges and payments will be presented vis-a-vis PVs - not to explain the scientific terms. 
I reckon the the KISS principle applies - anyone looking at anything that uses or consumes electric energy such as a HWS or a heater (ie which adds to their bill) or reduces their bill such as  a PV system or a wind generator will have as their reference the charges on that bill - and maybe I live a sheltered life, but the electricity bills I see use kWhrs ie kilowatt hours. 
So all you need to know is how much your system puts into the grid and what they are going to pay you for it and if you are interested (for example if there is feed-in tariff) how much you are charged for what you use (so you reduce that and get a better financial benefit). 
Most people will see watts and kilowatts mentioned, few (other than on gas bills) will see joules or megajoules mentioned. 
That's why I put the table in - to give a rough indication of what you might expect at one size and a simple way to estimate output other sizes. 
This ain't a science test (already passed mine  :Wink: ) but an attempt to answer questions in a clear and simple way. No doubt some will love Chrisp's  explanation, I don't think it helps - and that it might make people see it as being much harder than it needs to be. 
But that's just me - we can all read and decide for ourselves.  :2thumbsup:

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## barney118

There was an ad in the paper today, stating a 1.5Kw system will produce ~2000kwh /yr say 5.4kw a day, given I use say 20 kwh day, I save approx 25% on my electric bill. Thats a quarter bill of $300 yr saving, if the system costs me $6k after rebates installed its a break even of 20 years to pay back ! not to mention if they class the income from the REC's at my marginal tax rate.
Do you get a 20 yr warranty? what about ongoing maintenance?

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## chrisp

> This ain't a science test (already passed mine ) but an attempt to answer questions in a clear and simple way. No doubt some will love Chrisp's  explanation, I don't think it helps - and that it might make people see it as being much harder than it needs to be.

  Bloss, 
I beg to differ.  I think we need to be clear about units and not cause more confusion:Units of *energy* are Joule and kWh.
Units of *power* are Watts (and kW)."*kWh*" is confusion because it looks like a unit of *power*, but it is actually a unit of *energy*. 
One is *energy* and one is the *rate-of-energy* (aka power).  Apples and oranges.   :Smilie:  
EDIT: Bloss, I greatly appreciate your contributions to the forum.  I'm just being a little pedantic on this as I believe that using units of measurement loosely will only add to the confusion of others. 
BTW, I'm not fully familiar with solar panel lingo, but I would suspect that "kWp" refers to kilo-Watt-peak - i.e. the maximum power from the panel under ideal conditions.

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## Bloss

Chrisp - I fully understand the technical difference and am sympathetic to your view, but our battle for precision is already lost in the wider end-user world IMO. In the electricity marketplace (utilities) the distinction is not maintained except by a few engineers - and for marketing purposes  perceived (correctly or not) as interchangeable. 
The universal measure in PV industry too is kWh or kWhp - and yes it is the rate of energy used (output) - as I said it's what people recognise as what they buy from their electricity supplier (on grid) or in a PV or other renewable system what they get paid for when they send it back into the grid. 
From the owner perspective when they are buying and selling what matters is not what is the nominal capacity of the system, but the measured output for which they are paid or for which they pay - and that is expressed in kWh. 
That notion is also useful when explaining to people too - we had a newspaper article in the ACT in which the author was complaining about the fact that the average size PV system in the ACT was just 1.8kW and he said something like 'barely enough to toast two slices of bread'. Of course a system that size in Canberra will produce enough electricity even on a winter's day to toast many loaves of bread!  :Rolleyes:  
Technical accuracy is a bit like the battle for 'good' English usage (whatever that is) - a battle worth fighting, but realising it is never to be won and that appeasement and compromise is inevitable.  :Frown:

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## peter321

> There was an ad in the paper today, stating a 1.5Kw system will produce ~2000kwh /yr say 5.4kw a day, given I use say 20 kwh day, I save approx 25% on my electric bill. Thats a quarter bill of $300 yr saving, if the system costs me $6k after rebates installed its a break even of 20 years to pay back ! not to mention if they class the income from the REC's at my marginal tax rate.
> Do you get a 20 yr warranty? what about ongoing maintenance?

  I am in the process of getting a 1.5KW system installed (by ecokinetics) and am looking at a 2 year payback, not a 20 year payback.  The high feed in tariff is for 7 years (then who knows).   From Bloss' chart Sydney should give 2250KWH  per year for a 1.5KW system, and when multiplied by 60c gives $1350 per year payback. (providing your supplier has Gross metering)  
In Gross metering the solar system is totally separate from your power usage as it has its own feed in meter which they pay you from.
$6K for a 1.5KW system sounds a bit steep (Ecokinetics is $2K) are you keeping your RECs?

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## Smurf

> Chrisp - I fully understand the technical difference and am sympathetic to your view, but our battle for precision is already lost in the wider end-user world IMO. In the electricity marketplace (utilities) the distinction is not maintained except by a few engineers - and for marketing purposes perceived (correctly or not) as interchangeable.

  Agreed there.  :Smilie:  
From time to time I need to explain technical (mostly but not always electrical) things to the general public as part of my employment. I learnt long ago to always state the facts correctly, immediately followed by a statement that puts it in context. 
"It produces 80 watts, enough to run an old style light bulb" 
"It's 10 kilowatts, that's ten thousand Watts and is about the same amount of power your electric stove would use with all the hot plates and the oven turned on at the same time".  
"The light is from LED's. They're the same thing as the indicator light on the front of your TV, it's just that these are brighter and we're using a lot more of them". 
etc.
And so on.

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## Bloss

> There was an ad in the paper today, stating a 1.5Kw system will produce ~2000kwh /yr say 5.4kw a day, given I use say 20 kwh day, I save approx 25% on my electric bill. Thats a quarter bill of $300 yr saving, if the system costs me $6k after rebates installed its a break even of 20 years to pay back ! not to mention if they class the income from the REC's at my marginal tax rate.
> Do you get a 20 yr warranty? what about ongoing maintenance?

  The Feed-in-Tariff (FiT) in NSW Solar Bonus Scheme for NSW | Industry & Investment NSW pays you a set rate for ALL the power you put into the grid from a PV system at 60c/kWh. So that would give you around $1200 a year. The electricity you buy will be costing you around 21c/kWh. 
In any case with a gross FiT you can effectively ignore what you use (although you do well to reduce it) as you get paid on the total output from the PV system at nearly 3 times the retail purchase price as I said. You should be able to get a 1.5kW system installed by a reputable installer for around $2000-$2500 - if you surrender your RECs (as most do). $6000 sounds like the price including RECs - too high anyway. 
There is no 'income' from RECs or the FiT for that matter - Centrelink Minister clarified that on 14 May although there is still a bit of uncertainty around getting it  paid into a bank account rather than offsetting a bill. The tax ruling is attached. 
Warranty varies - panels usually 25 years, inverters 5 years with extra cost options of 10 and more.  Warranties for 10 or 20 years are really pretty useless given few companies last that long! Who are you going to make the claim against? So main thing is to buy a known good quality brand form a company you know or have good references about. 
Like most things mechanical things are likely to go wrong in the first few months and year. The panels will last 30-40 years if not physically damaged (and they are pretty tough). The inverter is the weak point traditionally, but they too have improved. Heat is their enemy so make sure the inverter is mounted on a south wall if possible or at least inside an airy cabinet that is well vented and provides shade from direct summer sun. 
At most standard roof angles the panels will 'self clean' although might need a hose down after very dry dusty spell or after one of those dust storm which 'rain mud'. Otherwise they simply sit and work - there are no motors or moving parts.

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## Smurf

My main source of heating is wood, using electricity only to supplement it when it's not cold enough to bother with the fire. No air-conditioning and the roof and walls are insulated. Cooktop is gas (electric oven). Hot water is heat pump on off peak. And I have solar panels (1kW) on the roof too. 
Given my electricity bills still amount to $900 a year, I feel genuinely sorry for those stuck with electric everything, no solar and no insulation. That is especially so for those in rental accommodation and on lower incomes - they're quite likely spending more on electricity than they spend on food. 
Getting a bit politcial I know, but these power price hikes are becomming a serious social issue. I can afford solar, gas etc so as to avoid huge power bills but many people have no option to install those things.  
Let's just say I'm not too happy with those who created this situation that is hurting many people. But all that said, if you're able to get solar installed cheaply, which you still can at the moment, then you'd be crazy not to.

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## Bloss

> Let's just say I'm not too happy with those who created this situation that is hurting many people.

  "I have seen the enemy and he is us!" - the whole of the industrialised world are those who created this 'situation' as we burn up fossil fuels in just a few hundred years which took billions of years to be created. 
Funnily enough Thomas Edison was as perplexed in 1910 as I am now when he said:  _This scheme of combustion to get power makes me sick to think of it -- it is so wasteful. You see, we should utilise natural forces and thus get all our power. Sunshine is a form of energy, and the winds and the tides are manifestations of energy. Do we use them? Oh no! We burn wood and coal, as renters burn up the front fence for fuel. We live like squatters, not as if we owned the property._ 
Those 'big polluters' that are easy targets do not do what they do in a vacuum - they do it so we can live the way we do (sure some more than others). If we want to continue living the same way we ALL will need to stop wasting energy and change to renewable sources for the energy we do use. The sooner we do so the easier and cheaper it will be. 
I'll stop now or Admin will flick my post to the 'debating' thread!  :Wink:

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## Johning

> Bloss, 
> I beg to differ.  I think we need to be clear about units and not cause more confusion:Units of *energy* are Joule and kWh.
> Units of *power* are Watts (and kW)."*kWh*" is confusion because it looks like a unit of *power*, but it is actually a unit of *energy*. 
> One is *energy* and one is the *rate-of-energy* (aka power).  Apples and oranges.   
> EDIT: Bloss, I greatly appreciate your contributions to the forum.  I'm just being a little pedantic on this as I believe that using units of measurement loosely will only add to the confusion of others. 
> BTW, I'm not fully familiar with solar panel lingo, but I would suspect that "kWp" refers to kilo-Watt-peak - i.e. the maximum power from the panel under ideal conditions.

  I totally agree with chrisp. My belief is that the energy supply companies perpetuate these units of energy (kWh) to make it difficult to compare the cost of electrical energy with that of gas. I also think that the term power station is a misnomer. They are energy stations. They generate energy. End of my rant. Getting to old to rant. :Doh: .
I agree with Bloss that the fight is probably lost.
Is science not taught in schools anymore?

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