Energy Matters Forums

[val]

The system has past it's one year date 25/2/11. I took a reading on the 366th day. Operating hours 4100, productivity 3215 kw. an average of only 8.78kw/day. miserable

My neighbour (opposite) has just installed a 1.65kw system and not only does it proportionally outperform mine by about 4-6%, it also operates at its maximum capacity during the middle of the day where mine can barely reach 1900w.

I have now heard of a recently installed local system (5+kw) that is considerably underperforming. It would seem the inverter is too small for the systems output. Like mine, this inverter gets too hot. Coincidentally this also has been installed by Solar Newcastle.

[cw nsw]

Val, given the historically cloudy 9 month period that most of coastal eastern Australia has experienced, your results are not necessarily way below par.

Equally, the output rates you were led to expect were somewhat unrealistic. 'Over the top' is a phrase that comes to mind - & a good many companies could be considered 'guilty' in this regard. Have a look at the CEC consumer information guidelines to see their average system output rates for the major cities.

http://www.cleanenergycouncil.org.au/ce ... arPV-guide

Sydney 3KW system = 11.7 kWh, 2KW system = 7.8kWh, which would imply 9.8kWh for a 2.5KW system, all things being equal.

[Russell Moore]

val, my system (5.04kW) has just passed a year as well, first full day of operation was 4/3/10, on the 4/3/11 the average for the year was 18.7kWh/day. So for a 2.5kW system that would be 9.35kWh/day average. Not all that more than your system is getting. I am in western Sydney.

Are you getting full sun ALL day? The best I can get now that I have had my large tree to the NE removed is full sun from 8am to 5pm most days, remember this will vary from season to season. Any shade will kill output, have you noted just how much shade you get? My system gets creamed on the pvoutput.org site from local systems that have no shade problems at all. (I still have neighbours trees to the east of me that block the sun early in the morning.

I have a Fronius IG40 inverter, and 28 180w Suntech panels.

[val]

i live in nsw, about 1 hr north of newcastle. the systems i am comparing it with are local to me so we all share the same weather. there may be some variances such as degree north, pitch of roof, etc. i experience some mid winter shading from neighbouring trees but comparisons have been made during summer months. comparisons by hour or day have not been favourable. my neighbour (opposite) has a 1.65kw system which currently produces 75% of my output. Next nearest neighbour (around corner) has 2kw system which seems to produce 90% of my output. both theirs are monocrystalline systems. is my system inferior or is it not working to capacity?

are the suggested average daily figures by region a 'minimum' ?

thanks for all the comments.

[Gordon-Loomberah]

How do your instantaneous outputs compare on a cloudless (so no local edge effect peaks) day at midday?

[cw nsw]

Val, the numbers in the CEC table are just 'average', & based on the following points.

Data Source: PV-GC spreadsheet based on the CEC GC Design Guidelines PV Array 1kWp facing true north and a tilt angle of 20° with an average inverter / wiring efficiency – 0.92, using long term average solar irradiation and temperature data from the Australian Solar Radiation Data Handbook

you may find it helpful to look at http://pvoutput.org for a broader range of comparisons - both in terms of your area & specific technology. some of us here input our data on a daily basis.

[Joey]

Val , very few systems will average more that 4kw per 1kw of installed panels averaged over a year , forget all the claims , huge summer figures and very low winter figures , 90% of rated output is very good but closer to 80% appears to be more common , there are many threads here that verify these figures.

I have 4.2KW of panels on a 4kw inverter , my average over 12 months is 16.6kwh per day , despite getting up to 31kwh per day in December and down to 7kwh per day in July it's only the average over the year that tells the real story.
Considering the below average weather in the east and some shading ,your system appears to be producing what I would reasonably expect.
I big misconception is that hot summers days are great for solar , this is wrong ,, The long days are great but long clear cool days ( the cooler the better ) are when solar is at it's best. A Solar panels worst enemy is Heat.

In your case I think your expectations are based on what sales people wanted you to think , not on the reality of Solar Production.

[val]

thanks Joey.
my 2.5kw system is 59.52% the size of your 4.2kw system yet it is producing only 52.89% of your output. same old story. i appreciate the many comments that have suggested my system is performing as well as could be exppected but that still does not explain why other systems are performing better. my neighbours 1.65kw system is 66% the size of mine but produces 75% of my output. Next neighbour 2kw system is 80% the size of mine but produces 88% of my output. not performing as well as i would have liked is one thing but being outperformed by smaller less expensive systems is a huge disappointment.
val

[Russell Moore]

Val,

Are you comparing inverter outputs or actual meter reading outputs? My Fronius inverter over reads by about 6% in comparison with the actual meter readings, and it is the actual meter readings that I use in my output figures as quoted.

My average daily output for mid Nov to mid Feb was 23.150kWh, so for you that would be 11.575kWh per day. As I have said I am in western Sydney, so I am not exactly next door!

If I was to be upset every time a local system out performed me, I would be a basket case, as I constantly get creamed by them. Not everyone has the same solar input, even if they are just down the road.

[cw nsw]

Russell - absolutely

Solar output is a bit like the Melbourne Cup, not everyone can be in the placings! Sounds like Val is in that big mid-field bunch - where most of us are. As with the Cup, pedigree & price are not always reliable performance indicators either.

Coming into my 'weakest' 4 months, I know of an identical system that is going to 'cream' me too! Then in spring when La Nina has disippated & there is less cloud cover, the numbers will make me smile again, even though they won't be in the placings.

on the +ve Val, your system has generated more than $1900 value in 12 months, & will continue so for a number of years ...