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Goth

Subsidies for home solar PV installations

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Personally, in the case of the systems advertised for zero overall cost, I'd be a little bit worried about the quality of the system, since they'd have to be honing the price down quite a bit to get it down to the point where they can pay for it, pay for installation, and still make a profit, just from the $9000 or so in the government handouts.

 

You wouldn't want a shonky system that burns down your house, would you?

Are you saying the "free" systems offered by some companies are likely to burn down your house?

 

The rest of your post around the costs seems fairly logical to me. If I was going to take this up I would only be looking at the zero overall cost options for my place.

 

Are there any components in the system that would prevent electricity from being used in the house if they failed? I'm guessing there'd be a switch that allows fail over to mains power which would need to continue to operate?

 

I was thinking of going with one of the zero overall cost solutions with the idea that when any component fails, the cost of replacement would be cheaper at that time and (hopefully) viable. And if it's not cheaper enough to be worth replacing, the system can stay there/be removed.

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A few thoughts into this excellent topic...

 

1. Scientific America did a study a few years ago and showed the best economics for solar power occurs when you super size the producing farm rather than shrink them to fit on a roof - there's a marked different in viability

 

2. Their is a technology shift approaching with the near commercialisation of thin layer printed plastic instead silicon as the current producing layer. The plastic works - is much cheaper, can produce about 800 metres of cells per day (with a bit more than half of silicon's current producing capability) it just needs to be proven to be durable.

 

3. All new technologies need investment funding for growth and later stage innovation and expansion, the challenging is making sensible decisions on where to start!

 

Matt

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Are there any components in the system that would prevent electricity from being used in the house if they failed? I'm guessing there'd be a switch that allows fail over to mains power which would need to continue to operate?

 

I was thinking of going with one of the zero overall cost solutions with the idea that when any component fails, the cost of replacement would be cheaper at that time and (hopefully) viable. And if it's not cheaper enough to be worth replacing, the system can stay there/be removed.

If the inverter goes kablewy spectacularly and shorts itself, then a fuse, circuit breaker or RCD might trip due to the nature of the fault. It's more likely that if the inverter dies, it'll die quietly and you'll just no longer be pushing energy back into the grid. I would certainly expect the internal fuses and safety circuitry of the inverts to simply remove itself from your circuits, and hence not cause any issues in pulling energy from mains.

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I was reading about this today before I logged onto Atomic (on the nuenergy site) as I had heard the "get this 1Kw system free with the rebate" blurb on the radio last week. I was all set to fill in the online form when I read about the "average savings" was $180 a year - which for us is less than 10%. I just doesn't seem worth the effort! I would dearly love to take a load off the grid and contribute to sustainability but to even make a noticable dint in our bill we would need at minimum a 3Kw system which I have no doubt would cost around 3x more and isn't subsidised.

 

now I have read Goth's OP which backs up my own discomfort about this situation. I'm not sure what is the right thing to do, but I'm not sure that spending $8k of govt money is cash well spent for such a small return.

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I question you need to average this over 24hrs in the day. It's solar - it's clear that it only works in daylight, so doing calculations based on a 24hr average really doesn't make much sense.

It doesn't really make any difference either way. You can say it's 175 W average over 24 hours, or you can say it's 350 W average over the daylight hours (let's suppose that's 12 hours per day for the sake of simplicity), but you get nothing at night, obviously. It doesn't make any difference. It's the same number of kilowatt-hours per day.

 

The data above averages (over days with poor direct sunlight to good full-light days) to around 3.2kWh per day, or around 1200kWh per day - so you're calculations are pretty good here.

That's good, it's always good to have more data to check. Though I can't help but point out that this real-world example gives even less than I expected.

 

That is definitely based on build quality - and you're probably far better off buying a high quality one, but it's definitely worth considering that in 10yrs time, a 1kW inverter is likely to cost far less (maybe 30-50% less) and be far more capable of standing up for a longer period.

True, but the fact is, most people will mostly go for the really, really cheap ones. To get the price down to the point where they can supply "zero cost" systems paid for only by the subsidies and REC, there has to be corners cut somewhere.

 

genuinely giving something back to the Environment and grid as a whole. There are cost savings to be had for what may be a reasonable investment, whilst possibly leading to a situation where the grid isn't in crisis in 10yrs time.

Giving something back to the environment and grid as a whole!? Look, I understand where you're coming from, you're trying to sell these systems, and everyone who tries to sell the systems pushes the hippy party line. But quantitatively, how much of a difference is it? Putting a 1 kW system on the roof of every single household in the country will deliver considerably less energy output than one single coal-fired power station. That's essentially useless, and you can do the same thing, indeed, far far more, for a far, far smaller amount of money.

 

It's not about replacing power stations, but more about a sustainable approach to support growth in the energy industry.

Yes, "sustainable growth in the energy industry" means alternatives that replace coal-fired power stations. "Growth in the energy industry" means more energy generation, and "sustainable" means not more coal stations, but clean alternatives which actually work as alternatives to building more coal-fired stations.

 

but i seem to remember an array of mirrors in a dish that focused sunlight on a small solar cell ..

less money spent on cells while keeping the same theoretical surface area by using the cheaper mirrors...

was wondering if this was viable or the solar cell had to be of higher grade to withstand the increased operating temperatures...

also having a tracking device which follows the sun thought out the day/year cycle gives a substantial increase in power..

any thoughts/further info would be much appreciated :)

Well, larger concentrating solar PV "stations" are far, far more economically viable than rooftop PV panels.

 

http://www.solarsystems.com.au/

 

It's still hugely, hugely expensive compared to wind and nuclear and other things, though.

 

Are you saying the "free" systems offered by some companies are likely to burn down your house?

Not really, but I'm saying they must really be scrimping on the costs to offer these systems, with installation, including the panels and grid-connect inverter, for "free", and only funding them from the value of the subsidies, whilst still making a profit.

 

If I was going to take this up I would only be looking at the zero overall cost options for my place.

 

 

I was thinking of going with one of the zero overall cost solutions with the idea that when any component fails, the cost of replacement would be cheaper at that time and (hopefully) viable. And if it's not cheaper enough to be worth replacing, the system can stay there/be removed.

Well, I think it's a waste of the Government's money, but obviously for the home owner, you don't have anything to lose. (Assuming you're insured against house burning down)

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Are there any components in the system that would prevent electricity from being used in the house if they failed? I'm guessing there'd be a switch that allows fail over to mains power which would need to continue to operate?

I think you'd lose all electricity if the grid-connect inverter blew up, since your whole connection to the grid goes through it, so I would hope there's the means to bypass it.

 

1. Scientific America did a study a few years ago and showed the best economics for solar power occurs when you super size the producing farm rather than shrink them to fit on a roof - there's a marked different in viability

Exactly, these sorts of things, like the Solar Systems work linked above, are far, far more cost effective. But they're still enormously expensive for the same scale of energy output compared to other clean energy alternatives.

 

2. Their is a technology shift approaching with the near commercialisation of thin layer printed plastic instead silicon as the current producing layer. The plastic works - is much cheaper, can produce about 800 metres of cells per day (with a bit more than half of silicon's current producing capability) it just needs to be proven to be durable.

People have been talking about gallium arsenide PVs, and cadmium telluride PVs, and stacked-heterojunction devices, and dye-sensitized titanium dioxide cells, and sliver cells, and all manner of things with respect to advanced solar cells for years and years and years.

 

But none of it is actually on the market being used anywhere. If you go and buy rooftop PV modules for your house, they are all still just old fashioned polycrystalline silicon wafers.

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The best and most effective ways to harness solar power to reduce your power consumption is:

 

  • solar hot water systems
  • passive solar heating, and
  • sun smart home design

When it comes to harnessing the power of the sun, the absolute best way is nuclear fusion (pity it's gonna take decades to get there though...).

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A few thoughts into this excellent topic...

 

1. Scientific America did a study a few years ago and showed the best economics for solar power occurs when you super size the producing farm rather than shrink them to fit on a roof - there's a marked different in viability

 

2. Their is a technology shift approaching with the near commercialisation of thin layer printed plastic instead silicon as the current producing layer. The plastic works - is much cheaper, can produce about 800 metres of cells per day (with a bit more than half of silicon's current producing capability) it just needs to be proven to be durable.

 

3. All new technologies need investment funding for growth and later stage innovation and expansion, the challenging is making sensible decisions on where to start!

 

Matt

A good article on Crystalline vs. Thin-Film PV here

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boondoggle

LOL wut?

 

oh okay boondoggle, yeah...

 

 

My gift to you. A new word for your vocabulary. Use it wisely my son.

 

 

I want these, if only for their badass, super villain look.

Edited by MisterK

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