Do you have solar panels?

[Smurf1976]

More panels facing North is out of the question without large frames etc which I am not prepared to install. Firstly for aesthetics, secondly because it wouldn't be the first time that we had winds well over 100 km/h, thirdly because facing E or W will still produce about 88% as much energy over 12 months (most of the loss being in Winter) so there's not a lot to be gained.

As for the inverters:

The first one and 6 x 170 W panels cost me literally nothing. Adding the extra 2 panels results in a production loss due to the capacity limit on the inverter which is trivial, 1 or 2% at most, so there's no point upgrading.

The second inverter cost me all of $400 (brand new, still in the box) and was installed with the intention of only ever connecting 8 x 190W panels (1.52kW). Given that those panels face East, there is a trivial production loss associated with having a smaller inverter.

Then the rules changed to allow systems greater than 3kW and that's where the West facing panels come in. From a purely economic perspective, adding another 1600 kWh of production without the need for an additional inverter stacks up fairly well. Overall, there's a loss of about 750 kWh of production from the E and W facing panels due to the undersized inverter. That is, they produce 3100 kWh of the 3850 that's theoretically available.

In terms of electrical connections, these inverters have only one MPPT (Maximum Power Point Tracker) so yes there are some losses from that too, although the under-sizing makes them of minor consequence since that is the greater constraint. The use of 9 panels facing W is specifically to match the current and voltage profile of the E facing panels as closely as practical.

It's an economic decision to have it this way for the moment. That is, with the uncertainty about future FIT rates it is not necessarily going to be worthwhile to invest further in the system in order to produce another 750 kWh, practically all of which would be exported to the grid. With that uncertainty, pumping out a solid 1.1kW all day, plus the N facing system with it's "normal" production profile, is a lower financial risk proposition.

Suffice to say that I've done the maths on this in considerable detail with the specific aim of doing solar, but only if it's profitable. That has lead to the system I have now. Taking the extra 750 kWh that is available just hasn't stacked up from a cost and financial risk perspective thus far. If I get another inverter, it makes sense to get one that's big enough to take the system all the way to 9.92 kW. But that doesn't stack up financially unless I then actually install the additional panels - which only makes sense if the FIT is high enough. Hence no action until the issue is resolved.

Once there's an announcement about the future FIT for Tasmania then I'll be able to make a decision as to what, if anything, to do next. At the moment it's "wait and see". Heck, we don't even know who will be retailing electricity in this state as of 1 January next year.

In terms of the broader industry shakeup going on down here:

1. Aurora Energy Tamar Valley (AETV), the only large fossil fuel power plant in Tas, was transferred to Hydro ownership on 1st July. Hydro now operates every significant power station in Tasmania, the rest being a few co-generation plants in industry, landfill gas, rooftop solar etc.

2. Aurora Retail will be out of business after 31st December 2013. Who is buying it is unannounced at this point, other than to say that the law prevents Hydro from retailing within Tasmania either directly or via any of its' offshoot companies. So presumably, the new retailers will be AGL, Orign, ERM or someone like that. That's assuming they want to do it of course.

3. Residential solar FIT is under government review in the context of point 2 above with a decision due fairly soon.

4. Aurora Distribution (the "poles and wires" business) will be taken on by Transend Networks (which owns most of the transmission network) in 2014.

All this is of course subject to politics amongst other things and assuming that someone actually wants to buy the Aurora Retail (which is being sold in two halves).

Suffice to say that I'm waiting to see how it all unfolds before investing any more in solar at home.

 

[sptrawler]

The FIT in W.A now is about 8c, which actually means the electrical supply authority is making money.
However the cost of installing a system has dropped considerably.
I recently installed a 1.6kw systm with a 5kw inverter for $2k, which really makes the panels $1/watt, can't be bad.
Now just have to wait for cheap panels.

 

[drsmith]

Then the rules changed to allow systems greater than 3kW and that's where the West facing panels come in. From a purely economic perspective, adding another 1600 kWh of production without the need for an additional inverter stacks up fairly well. Overall, there's a loss of about 750 kWh of production from the E and W facing panels due to the undersized inverter. That is, they produce 3100 kWh of the 3850 that's theoretically available.

How flat is the roof the east and west facing panels are on ?

 

[Smurf1976]

How flat is the roof the east and west facing panels are on ?

Roughly a 30 degree pitch.

 

[drsmith]

Roughly a 30 degree pitch.

Intuitively (without actually doing the math), I do find an 80% efficiency the east/west component of your setup surprising.

One factor could be cloud. On a cloudy day, 3.77kW of panels connected to a 1.1kW inverter in going to be far more efficient on a cloudy relative to inverter size than a system whose max output is rated at or near the max inverter capacity.

A while ago, I did some calculations on adding an extra 0.76kW of panels (4 panels) to my existing 1.52kW system connected to a 1.5kW inverter (max output 1.65kW). Based on the max inverter output figure, some 80% of the electricity generated from the extra 4 panels would feed through. I haven't done it because after discussion with the manufacturer (Growatt), the start up voltage of the panel array would exceed the maximum for the inverter. I purchased only one of the standard off the shelf systems without consideration for expansion at the time. That being said, it was relatively cheap, has proven to be reliable so far and will pay itself off in under 3 years.

The 1.52kW system facing slightly west of north at a roof angle of 22.5 degrees generates about 2500kW/year.

 

[Smurf1976]

Intuitively (without actually doing the math), I do find an 80% efficiency the east/west component of your setup surprising.

One factor could be cloud. On a cloudy day, 3.77kW of panels connected to a 1.1kW inverter in going to be far more efficient on a cloudy relative to inverter size than a system whose max output is rated at or near the max inverter capacity.

On a cloudy day, or even simply during Winter, there is minimal loss due to the inverter capacity. So it's only on a clear day in the warmer half of the year that the losses occur. There can be quite a big loss on a clear day in December, but overall it's not as large as one might expect.

Contrary to popular opinion, generation of electricity from solar is basically a "slow grind" that occurs every day. Even in mid-Winter in Tasmania there is still significant output. But, and here's the point, the vast majority of production will occur at levels well below peak output since "ideal" conditions aren't something that occurs every day. As a rule of thumb, a 2kW system will rarely put more than 1.6kW into the grid, and most of the time it will be quite a bit less than that. So losing peak production due to a small inverter doesn't affect total annual output as much as you might expect.

So far as the technical aspects of over-powering inverters are concerned, it is make and model specific. Some will simply limit their own output to a set level (eg 1.1kW in my case) whereas others will attempt to use whatever the panels can supply and destroy themselves in the process. Don't even think of doing it without checking the technical specifications of the inverter in question.

As for voltages, the issue relates to open circuit (no load) voltage of the panels on a cold day. This will be considerably higher than the normal operating voltage but it it exceeds the input voltage limit of the inverter then most likely the magic smoke will come out. So this needs to be worked out properly before connecting anything.

At this point I should add that rooftop solar wiring operates at a significant voltage (DC) which can easily burn or kill someone. It's not like having a few AA batteries or even a car battery - we're talking 300, 400 or more Volts here and that's nasty stuff. By law, working with this is a job for a properly licensed person and not something that anyone should attempt to DIY.

If you want to DIY for reasons of education etc then get a 12V panel, a regulator and a battery and use it to run some 12 Volt lights or something like that. You won't electrocute yourself and, as long as you don't manage to short circuit the battery, it's reasonably safe. Such a thing is within the capabilities of anyone with basic knowledge who can use hand tools, but messing about with grid-connect systems (or any mains wiring) is definitely not something to consider doing yourself.

 

[drsmith]

In the West, the economic chickens of government subsidies for solar panels are coming home to roost for a second time,

Hundreds of thousands of WA households could be hit with higher electricity prices under a proposed shake-up of bills aimed at recovering the massive cost to the system caused by the popularity of rooftop solar panels.

One suggestion is to raise fixed charges, another is a straight-out levy on householders with solar panels.

The residential feed in tariff is quiet low at about 9 cents per kWhr, but the issue could be more with electricity that is generated by the panels and not fed into the grid thus reducing consumption from the grid itself and hence revenue. If that's the case, applying the feed in tariff to all that is generated from the solar panels (gross as opposed to net) for new installs would help stem some of the financial bleeding from the utility.

It is not known whether the Government would consider a cut in consumption charges to offset any fixed-price move or opt for a straight-out levy on householders with solar panels.

It's not difficult to imagine the other states suffering the same sort of problem.

http://au.news.yahoo.com/thewest/a/-/newshome/17996196/power-supply-shake-up/

 

[sptrawler]

In the West, the economic chickens of government subsidies for solar panels are coming home to roost for a second time,



One suggestion is to raise fixed charges, another is a straight-out levy on householders with solar panels.

The residential feed in tariff is quiet low at about 9 cents per kWhr, but the issue could be more with electricity that is generated by the panels and not fed into the grid thus reducing consumption from the grid itself and hence revenue. If that's the case, applying the feed in tariff to all that is generated from the solar panels (gross as opposed to net) for new installs would help stem some of the financial bleeding from the utility.



It's not difficult to imagine the other states suffering the same sort of problem.

http://au.news.yahoo.com/thewest/a/-/newshome/17996196/power-supply-shake-up/

The big problem is people with 5kw systems, getting $3,000 payments from the government.
I don't think the FIT system was designed for consumers to become private generation companies.
The system should be designed to encourage people to mitigate their own usage.
Not encourage them to make it a money making venture.

 

[Julia]

The big problem is people with 5kw systems, getting $3,000 payments from the government.
I don't think the FIT system was designed for consumers to become private generation companies.
The system should be designed to encourage people to mitigate their own usage.
Not encourage them to make it a money making venture.

All that should have been properly thought out before launching the scheme. Yet another Labor 'initiative' that results in the end in massive inequity.

 

[Smurf1976]

Electricity distributors rely largely on volume consumption to recover fixed costs. That's pretty much how it's always been and, with the exception of Tasmania's highly controversial experiment in the mid-1990's, nobody in Australia has really tried to do anything different.

In short, if your consumption is below average then typically you are paying less than the true cost of supply, subsidised by those with higher consumption. How this comes about, be it using solar, running as much as possible on gas or simply being frugal is irrelevant. It's the net consumption level which counts - and if that's low then you aren't paying the fixed costs of the network.

It's a difficult argument however since charging people $200 a quarter (in 2013 $) before they even switch anything on is a hard sell politically. It stacks up very well from a purely rational perspective, but the mid-1990's attempt in Tasmania was without doubt the most unpopular thing any Australian electricity utility has ever done. Unpopular to the extent that attempts to survey public opinion took quite some time to find anyone who supported it (excluding electricity industry employees and politicians). The opposition was well over 99%, and public submissions to a formal investigation resulted in only one person arguing in favour of it.

And so the attempt to allow an "open access" network where anyone could generate power and the financial imperative to sell as much as possible was abruptly terminated for political reasons. After that, the industry went back to trying to sell as much electricity as possible with a sustained advertising campaign based on unit prices between double and triple the rate they had been before. Oddly enough, consumers were quick to use more of the now far more costly power, to the point that finding ways to generate enough power soon became the new problem.

Rumor has it that most of the big energy companies are now pondering how to implement something very similar to what was tried in Tasmania two decades ago. The industry is now much further removed from political and public influence, and has less need to compete against gas (since the gas and electric companies are largely the same) and wood (which has simply gone out of fashion). Solar is the only real threat now, and introducing such a pricing mechanism creates a "doesn't matter anyway" scenario for distributors.

Amidst all this but sort-of related, there will be a massive shift in generation patterns soon anyway. Gas is being re-priced and effectively becomes uneconomic for baseload generation, hydro production will return to more normal levels as the water runs out, and the various goings on create a greater exposure to the black coal market price as well. So we'll see the brown coal plants in Victoria running flat out 24/7 once again, and that's going to happen with or without a change in the carbon tax with the only differences relating to timing.

 

[Macquack]

The residential feed in tariff is quiet low at about 9 cents per kWhr, but the issue could be more with electricity that is generated by the panels and not fed into the grid thus reducing consumption from the grid itself and hence revenue.

Isn't that the whole concept of solar, to reduce consumption from the grid???

If that's the case, applying the feed in tariff to all that is generated from the solar panels (gross as opposed to net) for new installs would help stem some of the financial bleeding from the utility.

Surely, solar would become completely uneconomical in that case.

 

[Crows]

All that should have been properly thought out before launching the scheme. Yet another Labor 'initiative' that results in the end in massive inequity.

Could have said the same thing when the Libs sold ETSA, well for the most part.

 

[Julia]

What is ETSA?

 

[Boggo]

What is ETSA?

Built by taxpayers, lease sold off by a govt and now run by Spark Infrastructure (SKI)

ETSA UTILITIES: ETSA operates and maintains the electricity distribution network
in South Australia. Services are provided throughout major metropolitan areas,
including the capital city of Adelaide. ETSA operates its distribution network
under a 200 year lease from the South Australian Government, which commenced in
January 2000.

 

[Julia]

Thanks, Boggo.

 

[drsmith]

Isn't that the whole concept of solar, to reduce consumption from the grid???


Surely, solar would become completely uneconomical in that case.

The problem is that subsidies for solar have made electricity more expensive and hence less economical as a whole.

It has been a backward step in terms of overall economic efficiency compounded by governments not moving fast enough to wind back subsidies as the cost of solar hardware has decreased.

In Western Australia, 2,000 households are currently applying to install solar panels every week.

 

[Smurf1976]

What is ETSA?

Electricity Trust of South Australia.

It's the former state-run utility, equivalent to the State Electricity Commission of Victoria (SECV), NSW Electricity Commission or the Hydro-Electric Commission (HEC) in Tasmania. As with the others, it used to do everything required to supply electricity from mining the coal through to running power stations to reading meters and sending out bills to consumers.

Like many former public utilities, it was privatised (or in this case leased although a 200 year lease is for practical purposes the same as an outright sale) and then prices went up, up and up some more.

The point often missed is that there used to be pretty fierce competition between the various state authorities to attract major industrial loads, and between electricity and gas for heating and hot water. Victoria and Tasmania were always the most fiercely competitive, and that put a huge downward pressure on production costs and prices. NSW and Queensland, and to some extent SA, jumped on the bandwagon in the 1970's.

All that is gone now, with the new game being to raise prices rather than reduce them. Competition between the states is gone, and competition between gas and electricity is largely gone too. Prices are thus free to rise relatively unconstrained.

That's a bit off topic so far as solar panels are concerned, but suffice to say that as long as the current industry structure remains then electricity won't be getting cheaper. A token drop here and there perhaps, but we're not going back to the days when everyone could afford a warm home and a hot meal.

 

[DocK]

http://www.goldcoast.com.au/article/2013/07/18/454825_gold-coast-news.html

IT'S the residential "solar farm" fracturing friendships in a quiet Gold Coast street - and the council can't stop one popping up in your suburb.

Despite having 23 solar panels on his roof, Hope Island retiree Graham Drew has caused a furore by erecting a frame along his property to hold a 40 more panels.

At least five neighbouring households have repeatedly raised safety and aesthetic concerns with the council, including Mayor Tom Tate, but it says it is powerless to act as the structure was approved by an independent certifier and the city's planning scheme does not regulate the installation of solar panels.

I just heard this article discussed on the radio - I know I'd be upset if I lived next door to him.

 

[pixel]

http://www.goldcoast.com.au/article/2013/07/18/454825_gold-coast-news.htmlView attachment 53410


I just heard this article discussed on the radio - I know I'd be upset if I lived next door to him.

"Safety concerns"?
And how is a pergola covered with solar panels less aesthetic than one of Colorbond?
Grow up, peeps!

 

[DocK]

"Safety concerns"?
And how is a pergola covered with solar panels less aesthetic than one of Colorbond?
Grow up, peeps!

The concerns about it becoming a giant wind sail do seem credible to me - I assume the weight of solar panels is substantially more than your typical colorbond roof, and we are prone to the odd violent storm here. The glare from the panels would also be much, much more than their neighbours would normally get from a standard pergola roof. I'd be pretty upset if my neighbours were allowed by Council to erect the same structure right on my property's boundary and my home dropped substantially in value as a result - not to mention the eyesore!