Solar Panels

[Quickstatus]

Who is your electric retailer?

Best conditions for solar array is a Cool sunny day

 

[NM]

Who is your electric retailer?

Origin using their Solar Boost plan.

Best conditions for solar array is a Cool sunny day

Cool is relative, of course. Up here, 25 degC is considered cool (the temp at which the panel's nominal power output is measured). Peak air temp today was around 28 degC. Hotter days generally also means longer generation window (i.e. summer vs winter). The Power Temp Coefficient of the panels is -0.35%/degC, so drop in efficiency with increasing temp is fairly minimal.

 

[Deleted member 29185]

Enjoy the new panel benefit too. Panels will usually give better than their claimed wattage when they are brand spankers! That'll drop back after a little while.

 

[cove]

WA Government just raised electricity pricing by 7% commencing July1st because they can.

 

[NM]

Enjoy the new panel benefit too. Panels will usually give better than their claimed wattage when they are brand spankers! That'll drop back after a little while.

The panels I bought quote one of (if not the) lowest degradation rate over time for domestic panels. They come with a full 25 year product warranty as well as a 25 year power performance warranty. While most panel manufacturers offer a 25 year performance warranty, product warranty from most is 10 years, with LG now offering 15 years and SunPower 25 years. SunPower claims 35% higher generation after 25 years compared with "conventional" panels (compared with the top 15 manufacturers in 2015). The Power (performance) warranty is to achieve at least 95% of rated generation for the first 5 years, then -0.4%/year to 25 years. So at 25 years, they are warranted to be generating at least 80% of nominal power. While the performance warranty is -0.4%/year for 25 years, they claim that in practice it is -0.25%/year compared with conventional panel degradation rate of 1.0%/year (reference: Campeau, Z. et al. "SunPower Module Degradation Rate." SunPower white paper, Feb 2013; Jordon, Dirk "SunPower Test Report" NREL, Q1-2015.). In fact, SunPower claim their panels are manufactured for a 40 year useful life due to the use of a solid copper foundation being virtually impervious to corrosion and cracking that are the factors that cause degradation in conventional panels. But the price also reflects these performance claims. Time will tell.

 

[samh004]

Signed up for 17c/kWh FIT and 5% discount on the regular 24.51c/kWh usage tariff (making it 23.285c/kWh to purchase back from the grid. In today's market, 6.285c/kWh difference between FIT and consumption tariff is the best I could find.

Will speak to you over the weekend!

 

[RB]

The panels I bought quote one of (if not the) lowest degradation rate over time for domestic panels. They come with a full 25 year product warranty as well as a 25 year power performance warranty. While most panel manufacturers offer a 25 year performance warranty, product warranty from most is 10 years, with LG now offering 15 years and SunPower 25 years. SunPower claims 35% higher generation after 25 years compared with "conventional" panels (compared with the top 15 manufacturers in 2015). The Power (performance) warranty is to achieve at least 95% of rated generation for the first 5 years, then -0.4%/year to 25 years. So at 25 years, they are warranted to be generating at least 80% of nominal power. While the performance warranty is -0.4%/year for 25 years, they claim that in practice it is -0.25%/year compared with conventional panel degradation rate of 1.0%/year (reference: Campeau, Z. et al. "SunPower Module Degradation Rate." SunPower white paper, Feb 2013; Jordon, Dirk "SunPower Test Report" NREL, Q1-2015.). In fact, SunPower claim their panels are manufactured for a 40 year useful life due to the use of a solid copper foundation being virtually impervious to corrosion and cracking that are the factors that cause degradation in conventional panels. But the price also reflects these performance claims. Time will tell.

Thanks for the posts of the last couple of days-we are currently building and your posts have got me doing more reading. I noticed that there was a lot of discussion of replacement panels no longer being eligible for RECs- seems that this would mean it would be now more economical to buy quality up front rather than expecting to replace "lesser" panels down the track

 

[Deleted member 29185]

Thanks for the posts of the last couple of days-we are currently building and your posts have got me doing more reading. I noticed that there was a lot of discussion of replacement panels no longer being eligible for RECs- seems that this would mean it would be now more economical to buy quality up front rather than expecting to replace "lesser" panels down the track

What's a lesser panel? The biggest trouble I had when deciding upon my choice of panel was neither REC nor warranty, it was simply how to pick a good panel. Price has nothing to do with it. There are cheap Chinese panels that work well with no more indication of "shoddiness" than the expensive panels.

When I was purchasing my 30kW worth of panels, I came to the conclusion that the initial manufacturing warranty had some value (only as good as the company that you buy from however) and that the 25year output warranty was valueless as how does one prove a less than 80% output on a 25 year old panel? It would require NATA testing. That testing would likely cost more than the panels are worth and even then, you are still at the mercy of trying to claim against an international warranty in a foreign country. Good luck with that. The Chubb warranty (which was regularly claimed to be a silver bullet against all issues) was not even applicable to end-user residential type installations and meant basically nothing.

The RECs were (and still are) important, but to be honest, I didn't think a faulty panel replacement would receive a new lot of RECs as the initial REC calculation was not fulfilled and the replacement would be exactly that, no more RECs regardless.

My decision came down to price, research and a calculated gamble. Simple as that. I was speaking to a well know solar distributor/installer and he was desperately trying to sell me "his" preferred brand (supposedly European made) as they were far superior to any "lucky Dragon" panels. That was his favourite term to describe Chinese panels and in his infinite wisdom, there was no such thing as good Chinese product. At that stage I had been dealing in Chinese electrical products for a number of years and I had learned there was the complete gamut of quality available out of China, from absolute cough to really good stuff. The problem was how to work out which were which with solar panels. I had been quoted (from memory) about $1.60/W for the non-lucky-dragon panels and I have no doubt they were quality panels (which however, could still fail and need the warranty), as opposed to the ones I finally chose which were BLD at about $0.53/W which had a potential saving to me of about $32 000. I researched BLD. In Europe, they were sold as quality European panels ... no they weren't, they were Chinese, but hey, why let the truth stand in the way of a good sales pitch! At that point, they had been sold in Europe and Great Britain for about 5 years and I could not find any negative comment about them anywhere. I decided that it was worth the risk to spend the $16 000 and see how they go. It was a gamble, no doubt.

The guy I mentioned previously was scathing in his comments on line about me, even bringing in personal insults with regard to myself, my career and my knowledge, regardless of the fact he essentially did not know me. The really amusing part is, not long after, he started to import and sell "lucky-dragon" cough himself and justified it as being quality because he had personally tested it on his "wall of death"! His testing consisted of buying a product, overdriving it way beyond all it's specs and if it didn't smoke up, it must be quality gear! He appeared to quite genuinely believe that was a sound method of testing, but the desperation shown made me actually quite relieved I didn't listen to his hyperbole to start with!

I have no idea if my panels will actually last in excess of 25 years, but 5 years in without any failure of panels, no visible degradation and an output possibly a bit better than I had expected, is comforting.

 

[Deleted member 29185]

The panels I bought quote one of (if not the) lowest degradation rate over time for domestic panels.

I just realised NM, that you were replying to my post. That sounds great, but I was actually referring to the "burn-in" time rather than heat degradation. Most panels will show a better than expected initial output that makes you go "wow". That will drop back to the expected output after the shortish burn-in period. I can't remember how long my burn-in period lasted, but I was very impressed! Just sit back and enjoy the excess FiT!

A quick edit here. I notice the output warranty you say is claimed -0.4% per annum. Like all my photography, my photographic memory is flawed, but I think somewhere in this report they say the average is running at -0.08% per year which would make all those output warranty claims to be meaningless. I'm just about to go out (a reunion with some of my London buddies from 1986, so it will be messy tonight), so I can't check at the moment, but feel free to browse the report.

 

[Quickstatus]

I don’t have an array but when I do, the invested capital will be amortised over 10 years irrespective of any warranty

In this case at 5% quarterly to match electric bill period, the cost of the array would be about 11-12c/generated kWh

 

[Deleted member 29185]

I don’t have an array but when I do, the invested capital will be amortised over 10 years irrespective of any warranty

In this case at 5% quarterly to match electric bill period, the cost of the array would be about 11-12c/generated kWh

Not the same thing, but REC's or more correctly now STCs were based on the amount of electricity that can be generated over a 15 year lifespan. Unfortunately, they have now capped this at 2030 (12 years) so each year, the STC rebate is reducing. Don't leave it too long to invest!

 

[Quickstatus]

Yes. I always take a conservative approach . 10 years seems a fair balance

My final hurdle is this:

15kw planned
NE and NW roof orientation
Trees to the west blocks sun after 2pm in June, after 5pm in December
Option 1: 15kW on NE roof
Option2: 10kW on NE roof, 5kw on NW roof

NE roof can only accomodate 15kW
NW roof can only accomodate 10kW

Solar shop says NW roof will start generation a bit later in the morning
But both NE and NW array will be blocked by 2pm in June.

In Summer option 2 will be superior (total kW generated)
In Winter option 1 will be superior

Should I go option 1?

 

[cove]

I was thinking about a chainsaw trimming of a couple of those trees to make it an easier decision.

 

[Quickstatus]

I was thinking about a chainsaw trimming of a couple of those trees to make it an easier decision.

60m high x 35 trees

 

[cove]

Wow it is like a forest out there in NSW country. Do you have a picture?
Are you woken by birds singing?
We chose option two at our Perth home but we upsized the number of panels to cover the power the pool heat pump uses in winter.

 

[Quickstatus]

Wow it is like a forest out there.

2.5 acres of a 5 acre block
Looking NW . April Sun at 3pm

June Sun at 2pm would be at top right hand corner

 

[Deleted member 29185]

Option 1: 15kW on NE roof
Option2: 10kW on NE roof, 5kw on NW roof

NE roof can only accomodate 15kW
NW roof can only accomodate 10kW

Should I go option 1?

To get a NE and NW roof face, do you have like a V shaped house?
Is there a reason why you'd cap it at 15kW? Go 20kW (not a huge additional investment) and get the best of both worlds!

 

[Quickstatus]

Right angles to NE = NW.
House is rectangular.

Mistake spotted NW roof can accomodate 5kw (not 10kW)

Could go and max out the NE and NW roof area with panels but waste of capital as most of the kWh would only be exported at 13c/kWh.

Though I agree that going to 20Kw from 15kw would be a lower marginal cost

My issue has always been that the solar array will never cover the high cost period of 1400-2000hrs except perhaps 1400-1700 in summer.

The 15kw should cover this seasonally

 

[Deleted member 29185]

I am tired at the moment, but if the house is rectangular with (I assume) a pitched roof and let's say one side facing NE, isn't the other side facing SW?

 

[Quickstatus]

Pitched on all 4 sides