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Solar Power - Worth the Investment?


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The Ministry of War has been hassling me about getting solar power before the 30th June 2012 to ensure the Government rebate is secured.

My main concerns are about the amount of shade we have falling on the house early and later in the day. The neighbours have about 20 or more massive Tallowoods on a largish block of dirt and which cast a lot of shadows over the house in the afternoon. In winter, we might receive about 5 hours of good solid sunshine with a slightly higher amount for summer, say 6-7.

Considering the cost and the problem when one panel being in shade can affect the efficiency of all panels in the system, you'd have to be wary of the hype from the sales guys.

How many people have been told their system will generate XXX K/Ws per year yet the results are much less.

Assuming we installed a 3 or 4 K/W system (say around ($7K to $11K), it would take many years to ammortise the cost if shade reduces the systems output. I don't like the idea of having to spend twice the amount to have a system that has to generate twice as much power because of the shade. That is just bad economics.

Any there any SNA'er's with some real time figures from their own experience?

Thanks in advance.

Greg

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I feel that it's well woth it

My system is a 1.5 kw system with 8 panels

When I first got my system I was in the black from day one, however prices have gone up since and I am still getting low bills

So my advise is get a 5 kw inverter

16 panels on he roof

And expand if available roof space is available as required

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I should also add that, Solar Hot water will drastically reduce ones power bills

I installed Solar Hot water approx 12 years ago

So the next piece of advice is to get both installed at the same time whle the government subsidy is still available

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Get a survey done by your potential installer. They will look at angles and shade, and how it will change through the year. That said, I am moving shortly and won't hesitate on putting it on my new roof. Power bills are only going one way.

I second looking at hot water, but if you already have instantaneous gas and have a small household, the space might be better used for PV.

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Our hot water bill per quarter is between $28 to $35 so an investment of several $$$$$ for a HWS has less appeal due to the time to amortize the cost.

To reduce our annual bill of $1200 to $1400 has more appeal so long as I am not having to wait 20 years to get my money back by which time the whole system may have failed and would need replacing. The biggest consumer of power at Chez Greg is the pigeon pair of Kelvinators. I am told we consume slightly less power than the average family but then again there's only the wife and me so that stands to reason.

I don't mind being bill neutral but there is also the fact one needs to consider re the amount required to pay back the bank loan (tacked onto small mortgage with redraw)

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There are 3 types of cells: mono crystalline, polycrystalline and amorphous (in descending order or efficiency. Monocrystalline are most common now but despite having the highest power output, have the biggest efficiency loss through both heat and shading. It may be that getting some amorphous crystal panels will not only be cheaper but give you more consistent power generation throughout the day. The pay-off not only depends on the subsidy but also the feed-in tariff, and of course your power consumption. Minimising this is the most cost effective way to go. Another thing to ask your power company is whether they offer ToU metering (Time of Use). If so, and you buy a battery bank, you can sell all your generated power back to the grid during the day at higher prices, and buy power from the grid at night at lower prices to recharge the battery bank.

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Full Range is right. I have a 4.5 kw system and some shade in the morn with 80% of system facing west and 20 north. Also solar HW. No changes to the way in which we use power in the house.. 4 in the house and a teenager still at home with 5000 watts of stuff plugged in plus we have 2 fridges, 3 plasmas, 2 pcs etc (note Gas and wood heating) ....last year my electricity bill was $100.00...down from $ 2000, Need I say any more!

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There are 3 types of cells: mono crystalline, polycrystalline and amorphous (in descending order or efficiency. Monocrystalline are most common now but despite having the highest power output, have the biggest efficiency loss through both heat and shading. It may be that getting some amorphous crystal panels will not only be cheaper but give you more consistent power generation throughout the day. The pay-off not only depends on the subsidy but also the feed-in tariff, and of course your power consumption. Minimising this is the most cost effective way to go. Another thing to ask your power company is whether they offer ToU metering (Time of Use). If so, and you buy a battery bank, you can sell all your generated power back to the grid during the day at higher prices, and buy power from the grid at night at lower prices to recharge the battery bank. It's likely that you'd need to reduce your 2 Kelvinators to 1 efficient fridge.

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Get a survey done by your potential installer. They will look at angles and shade, and how it will change through the year.

We had a guy quoting from Brisbane using some newish online tool that is apparently much more detailed than Google maps. It looks at all aspects of your house and using 5 overhead satellite passes taken throughout the previous year, it gives a good indication of shade at frequent times.

He was able to suggest we chopped down the Poinciana tree at the front of the house (very detailed images) and ask the neighbours to trim theirs. (He even suggested we replaced one of the roof screws that looked rusty !!!)

We're getting another quote on Wednesday so it will be interesting to see how honest their assessment of the shade is.

One issue my brother mentioned was that it is his belief that energy credits are a form of income and would be subject to tax. I'm not sure of the ruling for this but his logic is sound based on what I know of the tax act. His potential installer was not able to confirm or deny his fears about the tax so he abandoned the install.

After checking all the issues, he reluctantly gave us a quote but included a caveat re the shade. I appreciated his honesty.

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I work in the solar industry, though nothing to do with PV. We considered and thoroughly investigated it as an option which was dismissed chiefly due to the lack of profit margin in superior quality panels. We just couldn't see a profitable enterprise unless the panels were sourced from China, with an average life expectancy of 20 years, after which the consumer has to start again. Worth considering in your calcs.

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So my advise is get a 5 kw inverter

16 panels on he roof

And expand if available roof space is available as required

We could look at putting some panels on the north facing roof as well as some on the rear pergola colourbond roof which seems to receive slightly more sun that the front now that the neighbours have removed 3 large palm trees on the eastern side.

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Re the credits - you need to have the gear installed by 30 June to get the federal government purchase credits (3 times REC's), not just ordered.

I am unsure what the status of the state government feed-in tariff is in Queensland.

I would be wary of significant shade issues - I don't have solar but have seen some places with perhaps 50% output because of shade. If you are able to trim your neighbours trees, can you trim them again in two years when they have grown back? What if your neighbours move and the new neighbours like their trees.

My suggestion is, if you are happy with the output with the trees, then go ahead. If you are relying on ongoing maintenance of neighbours trees, then don't kid yourself.

Benje

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Have a look at pvoutput.org, you should be able to find a system with a similar aspect and you can look at realtime figures.

Been checking out this site. Very good concept with some great results for Queensland being one of the best producers.

Thanks for the link.

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Re the credits - you need to have the gear installed by 30 June to get the federal government purchase credits (3 times REC's), not just ordered.

Benje

This is one of the more important issues we face now as more people try and book an installation before the cut off date. The govt may introduce a concessional period of time for the balance of units to be completed but I wouldn't bank on it.

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Can anyone answer what may end up being a few dumb questions.

If we consume around 17K/W per day (average is 20), and we install a 3 to 4K/W unit that produces around 15K/W per day then at a FIT price of around $0.44 to $0.52 per K/W hour then our system would need to be very inefficient (due to shade) for this to not pay off. Assuming:

15KW x $0.44 at 50% efficiency = $3.30 per day

Consuming 17K/W at around $0.22 per K/W Hour = $3.74 per day.

Net annual cost of power =$3.74 less $3.30 = $0.44 * 365 = $160.60

If that FIT price is locked in until 2018, this bad boy could be paid off quite quickly, particularly in the summer months.

If we spent a net price of $10,000 this would cost us roughly $750.00 in interest to pay back to the bank and would reduce each year.

Substituting a bank payback of $750 to $800 per year compared to $1,200 to $1,400 and rising for power starts to make a lot of sense even though I have been a bit dubious about output figures and the efficiency of some of these systems. I could throw some of my own funds into the ring to reduce the payback to the bank but I might just hang onto that for a while. If I factor in principal and interest, the bank payback will be about the same for the first year or so.

Perhaps I should bite the bullet after all.

In our case, now that I am out of work, I don't see we have much choice as I can't see power bills getting cheaper any time soon.

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This is one of the more important issues we face now as more people try and book an installation before the cut off date. The govt may introduce a concessional period of time for the balance of units to be completed but I wouldn't bank on it.

I believe you get 2 REC's for post 30 June instals as opposed to 3 REC's for a pre 30 June instal. Things change though. Quite quickly sometimes.

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The first thing I would be looking at is whether there is anywhere you could install the panels which gets less shade. Can they be put on a shed, on another part of the roof or the like?

Our experience is that we no longer have electricity bills. We have a 1.88KWh system in Melbourne. We use about 5KWh per day in summer and 15KWh a day in winter and we do have a teenage daughter (and I have a valve amp :D ).

The reason we don't get bills is that we have the higher feed in tarriff which was dramatically lowered by the present Liberal government, since our installation was before the feed in tarriff was lowered we get the old rate. What this means is that while we don't generate more than we use (in summer we do, but far short in Melbourne winter), but we get paid more for the excess we generate at any time (during the day when power is expensive) and pay when we use more than we are generating (at night when power is cheap). We are currently owed money by the power company and I think we will be about break even. Given power prices are only going to go up, carbon tax or no carbon tax, this gives us a measure of certainty we would not otherwise have.

Our reasons weren't just financial, we would have done this for environmental reasons whether there were subsidies or not. That aspect is for you to decide.

As an aside, do you have a tiled roof? The one problem we had was broken tiles after the installation. They should have said something before installing. 2 blokes carrying heavy solar panels across a tiled roof will break tiles, you just can't be that careful when negotiating a roof with a heavy solar panel. If you have a tiled roof get about 30 spares and when they install tell them to replace the broken tiles with your spares.

DS

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Good advice David.

Thankfully our roof is zincalume (recently resprayed) and I just replaced a 15 year old polycarbonate roof on our rear pergola with a new zincalume one which captures about 50 square meters (for water harvesting in a new tank). This seems to receive slightly more sunlight than the front as the shade from the western and eastern neighbours is a bit more pronounced.

It could be possible to have a dual array panel system that can have some panels on the front (north facing side) with say 6 to 10 on the pergola roof with some racks to elevate the south end of the panels.

I'm getting 3 or 4 quotes to see what they all advise so hopefully we'll have some idea soon.

I'm not confident they all could guarantee an install by 30th June 2012 however.

Cheers,

Greg

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The reason we don't get bills is that we have the higher feed in tarriff which was dramatically lowered by the present Liberal government, since our installation was before the feed in tarriff was lowered we get the old rate. What this means is that while we don't generate more than we use (in summer we do, but far short in Melbourne winter), but we get paid more for the excess we generate at any time (during the day when power is expensive) and pay when we use more than we are generating (at night when power is cheap). We are currently owed money by the power company and I think we will be about break even. Given power prices are only going to go up, carbon tax or no carbon tax, this gives us a measure of certainty we would not otherwise have.

DS

Could you not put that higher feed in tariff arrangement you have to even better use by installing more panels and a stronger / additional inverter? That way you'd still be locking in at the rate you arranged years ago (I assume) and just need to finance a few more panels and the extra cabling / hardware?

On second thoughts, methinks someone would have thought of and blocked that possibility already

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just going through the whole thing now. its quite a mine field. gas boosted solar hot water went in last week. and is pretty amazing. to give you numbers government subsidy is around $2.5k and out of pocket should be under $3k still quite a slab of cash. and if have an old hot water service 10 years or older worth it I think. no its not an investment as such. a lot of it is also you just want to use less energy. well thats why am doing it. if gas goes up significantly then it might pay its self off. in performacne the 2 x solar collectors pointing north feeding a 215 L tank. even in autumn cold conditions have solar return temps of 50+ deg C which means we are hardly using any gas now for heating water which we want in the house at 50 deg C

solar electricity a huge minefield. you never will know I dont think what return is till installed and monitored for a year ! we're going a 3kw system am banking that will not quite cover our bill but make a good dent in it. in installation of panels I imagine everyone will have some compromise in installation but will still have some return.

I've gone through AGL for solar hot water and electric panels. because big company so have someone who is still around in the 25 years or so the warranty goes for. I also taking advantage of their interest free terms for 2 years, figuring helps the financials ! origin energy another big company also does interest free. when getting quotes check if they can install by june 30. otherwise you will pay $900 more after that for a 3kw system. overall for both solar hot water and electric panels we are looking for under $10k installed which is about as far as comfort level is in spending on this kind of stuff :)

nearmap is pretty good to look at house from above and many angles. its what most of the companies are using to check out over the phone. a site visit is a must though to settle on details and finalise. let you know how our installtion goes this friday for the electric solar panels. hopefully weather is good !

Edited by :) al
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Could you not put that higher feed in tariff arrangement you have to even better use by installing more panels and a stronger / additional inverter? That way you'd still be locking in at the rate you arranged years ago (I assume) and just need to finance a few more panels and the extra cabling / hardware?

On second thoughts, methinks someone would have thought of and blocked that possibility already

The feed in tariff rates only apply to the panels installed at the time. Officially you have to notify them of additional panels.

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