Matas. The Solar tracking array is a simple one that works as I have seen it in operation. The photovoltaic cell when exposed to sunlight closes the circuit and only when it is in shadow does it activate the device. At night is automatically goes back to the original position waiting for the morning sun. Cost is a big factor in solar so anything simple and easy is a better alternative.
Tracked Array
(54 posts) (12 voices)-
matas
MemberAlso IAEA, I have found the website PVOutput an excellent way to compare your system output to others around Australia, and especially in the same area.
http://pvoutput.org/list.jsp?p=1&f=output_date&v=20100919&o=gss&d=desc
Its quite amazing all the sorting (eg by postcode) and graphing that can be done.
Posted Monday 20 Sep 2010 @ 6:32:42 am from IP # -
matas
Memberthatmosis,
Sounds like a good system.
Simplicity is definitely desirable.I think that is the method this guy used for a controller -
http://www.briery.com/solar/solar_tracker.htmlThe website gives a detailed account of how to build a tracker.
Not sure if it is still working though.Posted Monday 20 Sep 2010 @ 7:00:29 am from IP # -
IAEA
MemberBenny writes...
<I'm in Perth, Lat 32deg and currently getting 7kWh from a 1.5kW array on a completely fine day. Average over last 6 months 4.9kWh or 3.2kWh/kW. System faces NE though.>
On 2nd. Nov., this 1.5kW tracked array did - 14.98kW. This is 9.986666kWh/kw. This is the highest it has been since the 5th. Feb. 2010
There would be very few, if any fixed/tilt array systems that could even come close to the performance of this 1.5kW sys. at Lat. -36. It has beaten consistantly systems at Latitudes further north of its present location.
Can anybody beat this fig. for one days output. To be consistant, shall we say that, that day be the 2nd. Nov.
Posted: Thursday, 4th November 2010
IAEA
Posted Thursday 4 Nov 2010 @ 8:42:10 am from IP # -
IAEA
Member"Solar Data: 2010
Last Power Reading: 0 W
Total 60W Bulbs: 0
Daily Yield: 11.97 kWh ....... Achieved: 2010-Feb-6
Total Yield: 5728.4 kWhPosted: 2010-Feb-7, 2:27 pm"
On the 6th Feb., 2010 a 1.5kW sys. yielded 5,728.4kWh total since commissioning. Today its output was 8353.78 kWh total since commissioning.
This is a difference of 2625.38kWh from 6 Feb. 2010 to 31 Jan. 2011. This is 7.3130362kWh per day.
This then calculates out to 4.875kWh/kW/day from the 6th. Feb. 2010 to 31st. Jan. 2011.
A truly fantastic achievement. I have kept detailed records of six different systems on the Eastern seaboard, four North of this 1.5kW array and one South of this system.
Suffice it to say that this 1.5kW array absolutely devours all that I stack against it as far as kWh/kW is concerned, and not total output.
As an eg: a 29.7kW fixed angle sys. had it performed at the rate this 1.5kW sys., it would have earned for its owner a staggering AUD$37.94 extra just for today. I do not think that one can sneeze at this extra amount, can one?
I have taken the FiT as being AUD$0.60/kWh.
IAEA
Posted: Monday, 31 January 2011 8:44 PM
Posted Monday 31 Jan 2011 @ 9:44:10 am from IP # -
IAEA
Member"Solar Data: 2010
Last Power Reading: 0 W
Total 60W Bulbs: 0
Daily Yield: 11.97 kWh ....... Achieved: 2010-Feb-6
Total Yield: 5728.4 kWh".................................
Solar Data
2011
Last Power Reading: 0 W
Total 60W Bulbs: 0
Daily Yield: 9.38 kWh
Total Yield: 8388.87 kWhA difference of 2660.47kWh. Not bad from a 1.5kW twin axis tracked array for 1 year.
IAEA
Posted: Monday, 7 February 2011 12:10 AM
Posted Sunday 6 Feb 2011 @ 1:10:27 pm from IP # -
IAEA
Membermatas writes...
"IAEA, this tracked system is interesting.
Can you give us some information about it."http://www.wssc.vic.edu.au/Index.aspx
Right hand side, near top of Home page.
IAEA
Posted: Monday, 7 February 2011 8:02 PM
Posted Monday 7 Feb 2011 @ 9:02:49 am from IP # -
IAEA
Memberhttp://meiwebcast07.eventbrite.com/
LIVE WEBCAST - The Future of Solar Power in Australia
Wednesday, November 16, 2011 from 6:00 PM to 7:30 PM (GMT+1000)
Carlton Victoria.LIVE WEBCAST
The Future of Solar Power in Australia
Click the green Register button above to watch the FREE live webcast of this seminar. You will then see a confirmation page containing the webcast link. The webcast will begin at 6pm on Wednesday 16th November.
Ultimately, all our power comes from the sun, but converting solar radiation to electricity directly using photovoltaics, or less directly through solar thermal power is still relatively expensive compared with the processes that convert the solar energy stored in coal and natural gas into electricity. But the cost is rapidly dropping. What are the prospects for photovoltaics and solar thermal? At what point do they become competitive and what might be the implications for the broader energy generation system?
Chair
Mr Tony Wood
Director, Energy Program
Grattan InstitutePanel
Mr Tristan Edis
Energy Research Fellow
Grattan InstituteDr David Jones
Program Coordinator - VICOSC
Bio21 Institute
University of MelbourneSpeakers
Mr Andrew Dyer
Non-Executive Director
BrightSource EnergyMr Stefan Jarnason
Technical Director
Suntech Power AustraliaProf Mike Sandiford
Director
Melbourne Energy InstituteMelbourne Energy Institute
University of Melbourne
T: +61 3 8344 3519
W: http://www.energy Grattan Institute
T: +61 3 8344 3637
E: info@grattan.edu.au
W: http://www.grattan.edu.auIAEA
Posted Tuesday 15 Nov 2011 @ 11:37:22 pm from IP # -
IAEA
MemberWSSC Solar Data
2011
Last Power Reading: 0 W
Total 60W Bulbs: 0
Daily Yield: 15.01 kWh
Total Yield: 10.5 MWhToday a 1.5kW dual axis tracker in the NE Vic. put up 15.01kWh.
This calculates out to 10.006666kWh/kW.
What an amazing performance from this sys.
I keep track of various sys. across Australia and had a 29.7kW fixed array in the ACT performed to this standard, it would have earned AUD$76.96 extra for its owner just for today. A truly stunning performance.
That bottom fig. of 10.5MWh is its total output since Aug. 2007.
IAEA
Posted Thursday 1 Dec 2011 @ 11:26:56 am from IP # -
TAZ
MemberI have just finally finished installing my dual axis tracker that I built myself and as of today I have had my highest output of 19.40kWh from a 1.9kw system which comprises 10 190watt sun-tech panels and a SMA 3000watt inverter. I have been averaging 7.2kWh a day since the 22 of June so am expecting this to go up to over 10 kWh a day now that I have my tracker operational.Since the 15 of January I have generated 88.40kWh so a average of 11.05kWh per day for this period.
I obtained the controller from dave@axetracka.com Dave is excellent to deal with and is willing to make sure you get what you require. The actuators came from Melbourne satellite Services these are rated as 36 volt but I am running them at 24volt using two 20amp SLA batteries which are charged by two 5 watt panel, they handle the job with ease, cheers TAZPosted Sunday 22 Jan 2012 @ 9:51:28 am from IP # -
IAEA
MemberTAZ states:
.....my highest output of 19.40kWh from a 1.9kw system which ......The 1.5kW dual axis sys. put up 13.88kWh today. This is 8.955kWh/kW. Your production is outstanding from a Lat as you are situated in Tasmania.
Look fwd. to see some excellent summer production figs. from your sys. compared to those other fixed angle jobs that proliferate.
You maybe interested in PVOutput in being able to log your daily results and to be able to compare with others?
IAEA
Posted Sunday 22 Jan 2012 @ 12:14:42 pm from IP # -
photonthief
MemberTrackings systems are great fun, and are certainly capable of increasing energy yield for a given number of panels. I do not in any way wish to discourage enthusiasts from increasing yield using trackers.
From a strictly economic point of view though, it seems to me that trackers have become an obsolete technology, given the dramatic fall in the price of PV panels. In the 'old days' when panels were really expensive, it made economic sense to squeeze every last drop of energy from our very-high-cost panels, by investing money in tracking systems.
However, with the cost of panels now ~$1/watt, I strongly suspect that the most economical solution is simply to install a greater number of panels, all at a fixed angle. When the complexity and maintenance of a tracking system is considered, the case for a larger number of fixed panels becomes even stronger.
At first glance, it seems that one disadvantage of the 'brute-force-more-panels' approach would be that a greater area is required to accommodate the larger number of panels. Actually though, that is not true. The amount of sunlight energy falling on a given area of ground is a constant, from which it follows that for a given energy yield, the overall area occupied by the installation is always the same, regardless of whether the panels are fixed or tracking. In a tracking installation you get a greater yield per panel, but the tracked panels (or tracked arrays of panels) need to be spaced further apart to prevent shadowing of adjacent trackers in the morning and afternoon, with the result that the total area occupied is no less (and frquently more) than would have been occupied by fixed panels producing the same yield.
Posted Sunday 22 Jan 2012 @ 9:47:10 pm from IP # -
TAZ
Memberhi photonthief, the shadowing and spacing of the panels are more of problem on single axis tracking sytems, you do not have to space the panels any further a part on a dual axis sytems than if you where mounting them on a roof.
I am actually only taking up the area of a 1.9kw system,however going on my output since the installation of my dual axis tracker my installer as informed me that I am actually achieving the same output as a 3kw system but with the foot print of as I said a 1.9kw system.
As far as maintenance goes I can't see that I will have any maintenance to perform, the pivots that I have used are trailer axle stubs and hubs and the actuators are have no serviceable parts in them so apart than the washing of the panels I see little maintenance required.
Yes I could had increased the amount of panels to acheive the same results but in my view doing this can create a eye sore as you require a greater area to mount the panels which in it self can present problems.
cheers Simon
Posted Monday 23 Jan 2012 @ 12:35:03 am from IP # -
photonthief
MemberHi Simon, You are having fun and getting great results, which is all that matters.
Purely for academic interest I still insist that in general (or more precisely, when there are a significant number of trackers) it is not possible to obtain more power from the same ground area by using any type of tracking system.
To illustrate the idea, consider a large commercial installation, covering a flat area of 100m x 100m, 10,000 sqm total. At a particular time of day, say 10AM, the intensity of sunlight falling on this area might for example be 1kW/sqm (measured on a square meter of flat ground), so the total power available is 10,000kW, or 10MW if you prefer. At 10AM the sun will not be overhead, and for simplicity assume that the sun's rays are at an angle of 30 degrees with respect to the horizontal.
One option would be to cover the entire area with horizontal panels, like a tiled floor with no space between adjacent panels. For simplicity, let each panel have an area of 1.0 sqm, so you would need 10,000 such panels to cover the entire are in this way. Clearly this arrangement would catch every single incident photon, and it is not possible to do better. The total power incident upon the panels would be 10MW, and the electrical output would be 10MW multiplied by the efficiency of the panels.
Now, if you think about it, you cannot possibly cach any more photons (in total) by tilting the panels, or by mounting them on single axis trackers, dual axis trackers, or any tracker you wish to dream up. There is only 10MW of power available within the footprint area of 10,000 sqm, and that is all there is to it.
In this example, I said that the sun's rays are 30 degrees with respect to horizontal. Of course, you could tilt all 10,000 panels so that the suns rays were perpendicular to the surface of each panel, and that would increase the yield, wouldn't it? No, absolutely not. All that would happen, is that the panels would shade one another, such that the total power actually landing on unshaded parts of the panels was still 10MW. However, what you could do (and what real large-scale installations do do) is to tilt the panels optimally, and leave a space between adjacent panels, so that fewer panels are required.
Taking the argument a step further, you could also mount the panels on trackers but, try as you might, you will not get any more than 10MW from the same footprint area. However, what the trackers will allow you to do is to get close to the available 10MW with significantly fewer panels, spaced substantially further apart to prevent shading from adjacent panels.
Thus I repeat what I said previously, in the certain knowledge that it is correct for large installations.
"At first glance, it seems that one disadvantage of the 'brute-force-more-panels' approach would be that a greater area is required to accommodate the larger number of panels. Actually though, that is not true. The amount of sunlight energy falling on a given area of ground is a constant, from which it follows that for a given energy yield, the overall area occupied by the installation is always the same, regardless of whether the panels are fixed or tracking. In a tracking installation you get a greater yield per panel, but the tracked panels (or tracked arrays of panels) need to be spaced further apart to prevent shadowing of adjacent trackers in the morning and afternoon, with the result that the total area occupied is no less (and frquently more) than would have been occupied by fixed panels producing the same yield".
Are there any situations for which this reasoning does not hold true?
Yes, sort of, in some small intallations. My lunchtime is over, so I'll continue in a later posting.
Posted Monday 23 Jan 2012 @ 2:32:08 am from IP # -
IAEA
MemberTAZ states:
washing of the panelsI would encourage that you pay religiously to this task and put in place a weekly regime to maximise your ROI.
If it is possible to park your DA tracker overnight so no to little dew forms encouraging dust to accumulate on the surface, this will go a long way to offer you as clean dust free surface for insolation generation between panel cleaning.
Can you put up daily values your sys. does for all to see please?
Cheers,
IAEAPosted Monday 23 Jan 2012 @ 2:45:01 am from IP # -
IAEA
Memberphotonthief states:
you cannot possibly cach any more photons (in total) by tilting the panels, or by mounting them on single axis trackers, dual axis trackers, or any tracker you wish to dream up.Are you able to address this please?
The DA 3.00kW Tracker has been compared to a 4KW fixed tilt array at the same Lat.
Test performed Sept. 2008.
Cheers,
IAEAPosted Monday 23 Jan 2012 @ 2:57:57 am from IP # -
photonthief
MemberHi IAEA, You have quoted out of the context of the example that I gave. Please read the the example carefully, for the sentence that you quoted is most certainly true within the given example, for a GIVEN TOTAL FOOTPRINT.
Please also read my first paragraph:
"... I still insist that in general (or more precisely, when there are a significant number of trackers) that it is not possible to obtain more power from the same ground area by using any type of tracking system."The tracker performance that you ask me to address refers to a single tracker, not a large array of trackers as in my example.
I also said (right at the end) that the general principle that I described 'sort of' does not hold true for some small installations, and that I would continue the post.
Please be patient, and all your objections will be answered.
If you think that anything is wrong re the specific example that I gave for a large installation of fixed total footprint, please get back ASAP so we can thrash it out before I continue.
Posted Monday 23 Jan 2012 @ 3:33:30 am from IP # -
photonthief
Memberphotonthief said:
At first glance, it seems that one disadvantage of the 'brute-force-more-panels' approach would be that a greater area is required to accommodate the larger number of panels. Actually though, that is not true. The amount of sunlight energy falling on a given area of ground is a constant, from which it follows that for a given energy yield, the overall area occupied by the installation is always the same, regardless of whether the panels are fixed or tracking. In a tracking installation you get a greater yield per panel, but the tracked panels (or tracked arrays of panels) need to be spaced further apart to prevent shadowing of adjacent trackers in the morning and afternoon, with the result that the total area occupied is no less (and frquently more) than would have been occupied by fixed panels producing the same yield.Are there any situations for which this reasoning does not hold true?
Yes, sort of, in some small intallations.
To continue, one obvious example where the above is NOT true is for a single tracked panel, or a single tracker holding an array of panels. For simplicity consider the case of a single tracked panel. Ignoring the mechanicals of the tracking mechanism itself, the footprint of the panel is arguably no larger than the footprint of a single panel mounted at a fixed tilt. Well, sort of. If the shadow that is cast by the tracked panel is taken into consideration, then the 'effective' footprint, including the area shadowed, most certainly is bigger than for the fixed panel. This simply has to be the case, as was (hopefully) shown beyond doubt in the example of my last posting. By definition, the tracker tilts the panels to almost vertical in the early morning and late afternoon, which produces a longer, larger shadow than for the fixed panel which is less vertical.
If there is only one tracker, or only a small number of trackers, then it may be possible to locate the panels+trackers such that the shadows created do not fall on panel(s) from an adjacent tracker, in which case it could be claimed that the overall footprint is about the same as if the panels were fixed. However, the effective footprint when the shadows that are cast are considered most definitely IS larger for tracked panels, just as the effective footprint of fixed-tilted panels is larger than for horizontal panels. While you might get away with this for a small number of panels, for a large installation with a large array of trackers, you fundamentally cannot obtain a higher yield, relative to the overall footprint. In other words, in a large installation with trackers, the spacing between panels from adjacent trackers needs to be greater that if the panels were fixed, to prevent shading.
I apologize for making what is actually a simple concept, sound complicated. It is one of those things where, once you 'get it', you thereafter think it is obvious.
Finally, for anyone who doubts the example given in the previous posting, here is a useful analogy. Consider sunlight to be photons raining down, just like raindrops. The panel is like a shallow rectangular bucket, any photon (raindrop) that lands on the top of the bucket is captured. Throughout the day, the raindrops beat down at different angles, nearly horizontal rain in the early moring and late afternoon, and falling almost vertically at midday. For any given area on the ground, say 100m x 100m, who would doubt that the total volume of water that falls on that area is a constant, and that you can put your 10,000 buckets at any angle you like, and even 'track' the angle of your buckets throughout the day, but you fundamentally cannot collect a greater volume of water than would otherwise have landed on the ground. That, in turn, means that for any given total footprint area on the ground, tracked panels cannot gather more energy than fixed tilted panels, or more than fixed horizontal panels exactly covering the entire area.
Of course, tracked panels do give a higher yield per panel - that is why people do it.
Posted Monday 23 Jan 2012 @ 5:03:11 am from IP # -
dubbo teacher
MemberIAEA says
"The 1.5kW dual axis sys. put up 13.88kWh today. This is 8.955kWh/kW. Your production is outstanding from a Lat as you are situated in Tasmania."
Just remember IAEA that this time of year the further south you are the more sunlight hours you have. For example Hobert on 15 Jan would have 15 hrs, Sydney 14:10;
and Darwin 12:47. The opposite applies in winter.
So Tasmania should do well in summer at generating power but comparatively poorly in winter.
In fact I'd say tracked arrays are more of an advantage in the southern locations whereby just about anything'll do in summer but winter and the shoulder seasons are the issue and that's when sunshine is least available/most needed.Posted Monday 23 Jan 2012 @ 6:08:44 am from IP # -
wlb
MemberThere is one situation where a tracker does come into its own and can't be surpassed by fixed panels unless their number is very much greater, and that is for off-grid use.
When you are running a battery system, it isn't just the kWh total for the day that matters, but how early in the day the batteries are returned to full charge and how late in the day they remain full and on float.
Posted Monday 23 Jan 2012 @ 12:23:49 pm from IP # -
photonthief
Memberwlb said:
There is one situation where a tracker does come into its own and can't be surpassed by fixed panels unless their number is very much greater, and that is for off-grid use.When you are running a battery system, it isn't just the kWh total for the day that matters, but how early in the day the batteries are returned to full charge and how late in the day they remain full and on float.
Yes, it is not just the raw number of kWh produced that matters, but how that yield is distributed during the day, and a tracker is unsurpassed in that respect. It ain't just raw size that matters, but quality.
19kWh from a 1.9kW system is very impressive Taz, and all the more so because the system produces good power in the early morning and late afternoon.
On a cloudless day in Canberra at this time of year I get ~55kWh, which is not particularly good for 44x190W = 8360W of panels, though the inverter is only 6kW. However, I can't match the beautiful shape of Taz's output curve, which produces a greater proportion of the power when it is needed, in the early morning and late afternoon.
My output curve is enhanced by having half the panels facing NE, and the other half facing NW, but a tracked output curve is still better. An 8kW system certainly punches out the power, but does so through brute force and ignorance.
For off-grid applications, the 'add-more-panels' approach does have the advantage of outperforming a smaller tracked system on cloudy days. I can't recall ever having had a day when I produced less power than I used, and I use ~10kWh per day. When it is cloudy, you can't beat raw surface area.
In many cases, the superior performance of a tracked system may not be fully realised due to shading by trees etc, and I have plenty of them, though a tracked system is always superior for same number of panels.
A tracked system gives the best utilisation of the rated inverter power, beacause the additional yield is not achieved through a significantly higher peak power, but through increasing power at the start and end of the day. The result is that an existing system that is upgraded by adding tracking would rarely need the inverter to be upgraded. The same is somewhat true of my method of flattening out the power curve by having half the panels face NE, and half NW, which helps me get away with a 6kW inverter on 8.4kW of panels, but the inverter utilisation in a tracked system is still better.
Although academic, the rate of light induced degradation will presumeably be higher in a tracked system. For example, for a typical degradation rate of 0.7% per year, fixed panels will have degraded by 7% over 10 years, while a tracked system producing 30% more power per panel will have degraded by 9.1%. Not worth worrying about. However, the energy payback time will be shorter for a tracked system.
Personally I lean towards the 'add-more-panels' approach, but there are definitely advantages to the 'put them on a tracker' approach as well, especially for off-grid use.
Posted Monday 23 Jan 2012 @ 12:56:56 pm from IP #
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