Solar The Solar Panel Thread

Bellbirdweb

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Jan 24, 2014
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When i individually tested my cheapo dodgy 250w Ebay panel through the Victron MPPT controller i found shading one cell almost completely knocked out the entire panel
Yeah the shading example is a good one.

Most people think it will just drop it down a little but it almost kills it.

That’s why on my home system I’m getting micro inverters under each panel to protect against shading.
 

Macca_75

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Aug 3, 2016
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Morning all,

Interesting time to come across this thread. I just got back from 5 days away off grid yesterday and we had a bit of a play around with my cousins van as a comparison (he runs a 6kW inveter, a bank of batteries, small wind turbine, etc. All the 240V off grid you could want).

Aside from that, we noted at 1 point in the day I was getting around 2.5 - 3A in from the panel (confirmed by the standard PWM (I assume) controller). I have the *upgraded* 150W panel from factory.

I hooked up a Kings 120W blanket with it's standard MPPT controller to the Anderson lead on the van and got another 4A (as displayed on the Sewatec controller - so around 7 in total). The blanket was laying flat on the ground. This is when we started discussing the MPPT vs. PWM (I have never heard of it before).

So I am looking at changing the standard solar controller supplied by Jayco to a MPPT style one to try and get more value from the panel I have. Is it a start swap out? He has a unit like this

dba9af48-717b-416b-94b8-d39d609c85b6.jpg


and considers it pretty good value for money.

That's physically to large for a straight swap so I am thinking maybe something like this (maybe with the Bluetooth dongle or a connected display)

https://www.victronenergy.com/solar-charge-controllers/mppt7510#pd-nav-image

Is it as easy as a straight swap out?
 

mikerezny

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Sep 11, 2016
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Mount Waverley, VIC
Morning all,

Interesting time to come across this thread. I just got back from 5 days away off grid yesterday and we had a bit of a play around with my cousins van as a comparison (he runs a 6kW inveter, a bank of batteries, small wind turbine, etc. All the 240V off grid you could want).

Aside from that, we noted at 1 point in the day I was getting around 2.5 - 3A in from the panel (confirmed by the standard PWM (I assume) controller). I have the *upgraded* 150W panel from factory.

I hooked up a Kings 120W blanket with it's standard MPPT controller to the Anderson lead on the van and got another 4A (as displayed on the Sewatec controller - so around 7 in total). The blanket was laying flat on the ground. This is when we started discussing the MPPT vs. PWM (I have never heard of it before).

So I am looking at changing the standard solar controller supplied by Jayco to a MPPT style one to try and get more value from the panel I have. Is it a start swap out? He has a unit like this

dba9af48-717b-416b-94b8-d39d609c85b6.jpg


and considers it pretty good value for money.

That's physically to large for a straight swap so I am thinking maybe something like this (maybe with the Bluetooth dongle or a connected display)

https://www.victronenergy.com/solar-charge-controllers/mppt7510#pd-nav-image

Is it as easy as a straight swap out?
Hi,
I have a couple of observations before you go buy a new controller.
That seems like a significant difference in performance between panels. Did you check that the roof top panels were clean?
A 150W panel should be capable of delivering about 7A at 20V in good sunlight. Probably a little less since the panels are horizontal and thus not optimally aligned. A PWM controller should convert this to 7A into the battery. A MPPT controller will convert the entire 150W (less converter losses of maybe 5-10%)
So, about 135W into a battery at about roughly 13,5V would be 10A. Note, very roughly!

It is unlikely that the controller on the Kings panels is actually an MPPT. There are a lot of so called MPPT controllers that are just ordinary PWM.

cheers
Mike
 

Macca_75

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Aug 3, 2016
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Hi,
I have a couple of observations before you go buy a new controller.
That seems like a significant difference in performance between panels. Did you check that the roof top panels were clean?
A 150W panel should be capable of delivering about 7A at 20V in good sunlight. Probably a little less since the panels are horizontal and thus not optimally aligned. A PWM controller should convert this to 7A into the battery. A MPPT controller will convert the entire 150W (less converter losses of maybe 5-10%)
So, about 135W into a battery at about roughly 13,5V would be 10A. Note, very roughly!

It is unlikely that the controller on the Kings panels is actually an MPPT. There are a lot of so called MPPT controllers that are just ordinary PWM.

cheers
Mike
Thanks Mike. During the day I do see values pushing around 6A from the controller so given the panel is never perfectly aligned, a small amount of dust would be present (yes it was clean before we headed off but would not have been perfect at the time). I am happy with the 6A value given it is less that 100% perfect conditions (also was a hot day so panel would have been hot).

BUT

at the same time, same conditions, the 120W blanket outperformed m 150W panel. The blanket was on the ground near flat as well. Same light. I agree with Kings you get what you pay for and was surprised to see it outperform my panel, however going by the readings on the Sewatec Drifta panel that's what I saw.

My setup does seem to be working OK (peaks of 6A are close to 7A you note given environmental conditions, etc) , I am just curious as to if it could be better with a few extra $$$. 10A with a MPPT sounds better that 7A, especially if it can also charge for a longer period of the day. On a normal sunny day we don't have an issue but throw in a few overcast days and I will struggle.

If I get caught out there is always an option of connecting and running the car - that seemed to put 5A in.
 

mikerezny

Well-Known Member
Sep 11, 2016
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at the same time, same conditions, the 120W blanket outperformed m 150W panel. The blanket was on the ground near flat as well. Same light. I agree with Kings you get what you pay for and was surprised to see it outperform my panel, however going by the readings on the Sewatec Drifta panel that's what I saw.
Hi,
If you have seen 6A from your rooftop, that would probably be about as much as you can reasonably expect from a roof top 150W panel and PWM controller in good sunlight.
Out of curiosity, what is the maximum current you have seen from the Kings panel?

As regards upgrading the controller, you will certainly get an improvement by moving to a real MPPT controller. The advantage is that you get this extra power without adding extra weight. The alternative, of adding extra panels on the roof is more complex and adds weight.
In my opinion, a combination of roof top solar (which works whilst driving) and portable panels to boost as necessary and to cover the times when the roof top is in the shade is the way to go. A portable panel setup optimally should always outperform a roof top panel mounted horizontally, covered in dust and occasionally bird droppings. Certainly portable panels are easier to keep clean!

I have an anderson plug to alligator clips which I use on my portable panel to top up the car crank battery when camped for long periods since we almost never start the car until we leave. With all the opening of doors etc over a week or so, we flattened the crank battery.

Regardless of what your setup is, the most important part is understanding what you have and monitoring its performance and you are well on top of that! I am interested to see what improvement you get by upgrading to an MPPT controller.

cheers
Mike
 
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Macca_75

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@mikerezny - Looking at the Victron MPPT 100/20 SmartSolar. 20A will give me ~ 300W of panels (with a minor clipping if I achieve close to 100% efficiency). Would love to jump to the 30A model but that's another jump in price. With the 20A "if" I decide to add another panel in the future I am covered. Went SmartSolar over BlueSolar model as it has Bluetooth built in. I can add the separate MPPT Controller later if I need to have a constant display and can't be bothered with the phone - for an extra $120 doubt I'll add that.

I can't say what the max Amps from the blanket was, but at the same time (comparing the built in Jayco controller to monitor 1 x 150W panel only and the Drifta showing a combination of panel + blanket (minus usage which was at near 0 as I turned everything off for the test) the fixed panel was around 2.5A (peaking towards 3). The combined value of the blanket and panel was around 7.5A - peaking at 8 (so I can only conclude I was getting ~4A from the 120W blanket, laying flat on the ground in the same sun). Based on panel position it was a fair comparison. Dust on the fixed panel would be the only difference. Time was late-mid afternoon.

I have a dual battery in the car so I can un-isolate the 2 and jump start my own car - unless I flatten both (hasn't happened yet - but there is always a first time). The Anderson to alligator clips seems like a lightweight cheap insurance policy.

Going to be hard to compare 1 controller to the other unless I get a clear day and do a quick reading, swap and read. Honestly, that will only happen if it's a clear day when I fit the new one ;)
 

Drover

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Just play with 60% of bench efficiency @Macca_75 that will be a roughy of what you will probably achieve over the day in camp, unless you watch and move panels and be a bit anal....but then amount of storage and how much you drag out overnight comes into it......I find my 120w portable has nearly juiced them up by 1000 when the 200w roof top starts to come to life, the 120 is pointed at sunrise the night before with position and angle changes during the day, laptops, phones and cams get plugged in usually about 1100 to 1400, though the arvo internet session the laptop runs off tug aux , has its own solar....well that's how mine runs for days on end, 3 days of black clouds means the LRPS gets a run.
 
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Boots in Action

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Mar 13, 2017
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Morning all,

Interesting time to come across this thread. I just got back from 5 days away off grid yesterday and we had a bit of a play around with my cousins van as a comparison (he runs a 6kW inveter, a bank of batteries, small wind turbine, etc. All the 240V off grid you could want).

Aside from that, we noted at 1 point in the day I was getting around 2.5 - 3A in from the panel (confirmed by the standard PWM (I assume) controller). I have the *upgraded* 150W panel from factory.

I hooked up a Kings 120W blanket with it's standard MPPT controller to the Anderson lead on the van and got another 4A (as displayed on the Sewatec controller - so around 7 in total). The blanket was laying flat on the ground. This is when we started discussing the MPPT vs. PWM (I have never heard of it before).

So I am looking at changing the standard solar controller supplied by Jayco to a MPPT style one to try and get more value from the panel I have. Is it a start swap out? He has a unit like this

dba9af48-717b-416b-94b8-d39d609c85b6.jpg


and considers it pretty good value for money.

That's physically to large for a straight swap so I am thinking maybe something like this (maybe with the Bluetooth dongle or a connected display)

https://www.victronenergy.com/solar-charge-controllers/mppt7510#pd-nav-image

Is it as easy as a straight swap out?

Hi @Macca_75 , there are plenty of proper MPPT controllers better and smaller than the MakeBlue Sky above. That is a very large unit and uses slots in the casing for heat distribution when operating. The more modern ones have heavy aluminium mountings with fins to act as heat sinks and also have air flow behind unit. And they are a straight swap into the same position of the poorer Jayco (Topray Solar??) Be aware though that a lot of controllers call themselves MPPT but are really only cheap PWM type.
If you are considering a good and genuine MPPT controller, you do not have to buy one which needs a separate display screen and blue tooth/dongle. The Victron and Epever may be good units, but are pricey and need ancillary equipment to operate/monitor/adjust settings properly. If you are right into separate computer display screens, passwords, dongles etc, (and wish to spend extra money), then they are for you.

However, I have a LDSOLAR MPPT 30A unit which has ALL the bells and whistles of the others and has it all on a display screen on the unit itself. User adjustable LVD and LVR, charge voltage setting, float voltage setting, remote temperature sensor, continuous logging and more for around $150.00. I recommend you have a look at this controller as it is a GENUINE MPPT controller. I have had mine now for nearly 2 years and it is the real McCoy!!
The links for two sellers on Ebay are below.

https://www.ebay.com.au/itm/30A-MPP...?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc%
https://www.ebay.com.au/itm/LDSOLAR...rms=aid=111001&algo=REC.SEED&ao=1&asc=2016090

Here is a picture of my unit fitted in my Penguin where it is always clearly visible and there is no need for a separate display screen , blue Tooth/dongle. In any case, when I go off grid , I am often in places where there is no internet/phone reception or service.. Regarding output from panels, I have 1 X 180w panel and 1 X 200w panel (both portable) connected in SERIES and have achieved charging currents of more than 20A at times, but easily reach 16 to 18A when my single 120ah AGM is down a little. @mikerezny calculations are pretty accurate. Conversion losses (from DC to AC and back to DC - which is how a MPPT controller achieves max current especially in dull and cloudy conditions) is now only 2% and fast tracking of max power point is 99.5% on my unit. Whatever you buy, make sure you connect the LOAD through the solar controller so that you can display what is going OUT.

I hope this helps your decision making and maybe save you some dollars!!
 

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Macca_75

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Hi @Macca_75 , there are plenty of proper MPPT controllers better and smaller than the MakeBlue Sky above. That is a very large unit and uses slots in the casing for heat distribution when operating. The more modern ones have heavy aluminium mountings with fins to act as heat sinks and also have air flow behind unit. And they are a straight swap into the same position of the poorer Jayco (Topray Solar??) Be aware though that a lot of controllers call themselves MPPT but are really only cheap PWM type.
If you are considering a good and genuine MPPT controller, you do not have to buy one which needs a separate display screen and blue tooth/dongle. The Victron and Epever may be good units, but are pricey and need ancillary equipment to operate/monitor/adjust settings properly. If you are right into separate computer display screens, passwords, dongles etc, (and wish to spend extra money), then they are for you.

However, I have a LDSOLAR MPPT 30A unit which has ALL the bells and whistles of the others and has it all on a display screen on the unit itself. User adjustable LVD and LVR, charge voltage setting, float voltage setting, remote temperature sensor, continuous logging and more for around $150.00. I recommend you have a look at this controller as it is a GENUINE MPPT controller. I have had mine now for nearly 2 years and it is the real McCoy!!
The links for two sellers on Ebay are below.

https://www.ebay.com.au/itm/30A-MPPT-Solar-Panel-Regulator-Charge-Controller-12V-24V-Auto-Focus-Tracking-LCD/122480174080?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc%
https://www.ebay.com.au/itm/LDSOLAR-MPPT-Tracer-Solar-Controller-Charge-Regulator-30A-Caravan-Solar-12v-24v/183394172144?_trkparms=aid=111001&algo=REC.SEED&ao=1&asc=2016090

Here is a picture of my unit fitted in my Penguin where it is always clearly visible and there is no need for a separate display screen , blue Tooth/dongle. In any case, when I go off grid , I am often in places where there is no internet/phone reception or service.. Regarding output from panels, I have 1 X 180w panel and 1 X 200w panel (both portable) connected in SERIES and have achieved charging currents of more than 20A at times, but easily reach 16 to 18A when my single 120ah AGM is down a little. @mikerezny calculations are pretty accurate. Conversion losses (from DC to AC and back to DC - which is how a MPPT controller achieves max current especially in dull and cloudy conditions) is now only 2% and fast tracking of max power point is 99.5% on my unit. Whatever you buy, make sure you connect the LOAD through the solar controller so that you can display what is going OUT.

I hope this helps your decision making and maybe save you some dollars!!

Thanks - after more time on the internet yesterday I found the Victron SmartSolar 100/20 (100V/20A) for around $200. 20A would be more than enough for me I think. The SmartSolar has built in blue tooth (no display by default) so I can connect smartphone for free if I want to check point in time. Seems to have the same bells and whistles as yours above (I will check the links out now in more detail). I currently have 1 x 150W and MAY add a second of the same size - at 20A there may be a trivial time of day where I will get some clipping but how often are ideal conditions reached?

I am only interested in doing it right the first time.

The sample one above was what I saw running, not what I was looking at buying.

Off to check your links out now. Thanks
 

Moto Mech

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For those considering flexible solar panels, think again.
Our experience
2x 250w flexible panels, near $700ea.
Failed at 3yrs old, had worked very well up intil we experienced 40+ deg weather on a 12mth round Australia trip.
These panels were glued straight to roof of van(asked seller if it needed air gap who intern asked manufacturer and reply was no air gap needed) These were one of the first thin panels available.
3rd panel- $300 250w panel mounted on a frame as a portable unit. Lasted around 2yrs.
4th panel
200w $200 panel, lasted 2 months.
Was mounted to sq section laser lite(to allow air flow)
5th panel
200w (replacement for above panel)
Lasted 9 mths(van was stored over winter so actual use was 3 mths in sun)
Last two panels suffeted ‘heat spots’, lost most output.

So thats it for us, never touching flexible panels again.
06A0E8B8-F8D8-41F7-9D27-07375C91CE84.png
 
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Boots in Action

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Mar 13, 2017
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For those considering flexible solar panels, think again.
Our experience
2x 250w flexible panels, near $700ea.
Failed at 3yrs old, had worked very well up intil we experienced 40+ deg weather on a 12mth round Australia trip.
These panels were glued straight to roof of van(asked seller if it needed air gap who intern asked manufacturer and reply was no air gap needed) These were one of the first thin panels available.
3rd panel- $300 250w panel mounted on a frame as a portable unit. Lasted around 2yrs.
4th panel
200w $200 panel, lasted 2 months.
Was mounted to sq section laser lite(to allow air flow)
5th panel
200w (replacement for above panel)
Lasted 9 mths(van was stored over winter so actual use was 3 mths in sun)
Last two panels suffeted ‘heat spots’, lost most output.

So thats it for us, never touching flexible panels again.
View attachment 62625

With those sort of experiences @Moto Mech , no one could blame your thinking on the thin flexible solar panels. At first I thought you had been a little unlucky maybe or badly set up, but NOT 5 times. I have been following your bad experiences on this forum and sad to see your failures even if you are trying to do the right thing. Confirms what I have seen on an earlier posting about heat on solar panels and the vital need to have a good air gap and more importantly a good air flow at the rear of the panels . It seems that the thin panels are not able to disperse the heat build up anywhere near as well at the fixed glass covered panels, be they fixed or portable. I will look back on some of these posts and send you the link about heat and the openness of portable panels for reducing the heat generated. I have had my two portable panels for three years now and yes, in good old sunny (bluddie hot!) Queensland, the back of the panels get very hot, but have never failed. Maybe later technology will sort out these problems with the thin panels?? Cheers.
 

Boots in Action

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Mar 13, 2017
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With those sort of experiences @Moto Mech , no one could blame your thinking on the thin flexible solar panels. At first I thought you had been a little unlucky maybe or badly set up, but NOT 5 times. I have been following your bad experiences on this forum and sad to see your failures even if you are trying to do the right thing. Confirms what I have seen on an earlier posting about heat on solar panels and the vital need to have a good air gap and more importantly a good air flow at the rear of the panels . It seems that the thin panels are not able to disperse the heat build up anywhere near as well at the fixed glass covered panels, be they fixed or portable. I will look back on some of these posts and send you the link about heat and the openness of portable panels for reducing the heat generated. I have had my two portable panels for three years now and yes, in good old sunny (bluddie hot!) Queensland, the back of the panels get very hot, but have never failed. Maybe later technology will sort out these problems with the thin panels?? Cheers.

Hi @Moto Mech , found this link about other people having trouble with failed flexible solar panels, so you are not the only one. The following link is very good, and certainly would not make me even consider a flexible solar panel, but then I do not have to consider the weight problem. For those considering flexible solar panels, this is essential to see and consider before buying IMHO. Note in this video, there are no solar controllers with panels, so the controller must be inside the van and separate.

 

Boots in Action

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Mar 13, 2017
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@mikerezny - Looking at the Victron MPPT 100/20 SmartSolar. 20A will give me ~ 300W of panels (with a minor clipping if I achieve close to 100% efficiency). Would love to jump to the 30A model but that's another jump in price. With the 20A "if" I decide to add another panel in the future I am covered. Went SmartSolar over BlueSolar model as it has Bluetooth built in. I can add the separate MPPT Controller later if I need to have a constant display and can't be bothered with the phone - for an extra $120 doubt I'll add that.

I can't say what the max Amps from the blanket was, but at the same time (comparing the built in Jayco controller to monitor 1 x 150W panel only and the Drifta showing a combination of panel + blanket (minus usage which was at near 0 as I turned everything off for the test) the fixed panel was around 2.5A (peaking towards 3). The combined value of the blanket and panel was around 7.5A - peaking at 8 (so I can only conclude I was getting ~4A from the 120W blanket, laying flat on the ground in the same sun). Based on panel position it was a fair comparison. Dust on the fixed panel would be the only difference. Time was late-mid afternoon.

I have a dual battery in the car so I can un-isolate the 2 and jump start my own car - unless I flatten both (hasn't happened yet - but there is always a first time). The Anderson to alligator clips seems like a lightweight cheap insurance policy.

Going to be hard to compare 1 controller to the other unless I get a clear day and do a quick reading, swap and read. Honestly, that will only happen if it's a clear day when I fit the new one ;)

Hi @Macca_75 , this has been explained by me in earlier posts, but now KickAss has made a video on how to bypass or move the regulator on the back of the movable solar panel. Should make it a lot easier to understand how it is done. Hope this helps those a bit frightened to make this modification.

 
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Moto Mech

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Jul 18, 2012
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Mole Creek, Tasmania
Pulled flexible panel off top of van yesterday(mounted to laserlite sheet) and boy, dont muck around with fancy sikkaflex’s, just use good old roof and gutter silicone.
I really struggled to first, pull panel off laserlite and then even harder, pull laserlite off roof.
Anyway, Ive now fitted a 300W glass panel and is charging beautifully.
5E16BD5B-C2B5-4AC9-A5BF-225951E67F4A.jpeg

746DD225-6EE1-43D7-8CAF-292F303B34A3.jpeg
528B7B92-1AB2-495D-A3AF-5A086B6F9271.png
 
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Crusty181

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Crusty181

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Feb 7, 2010
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Mentone, VIC
This was the last one that failed about a month ago.
5th time bitten, learnt my lesson
Wow, Ive been postponing installing more panels because framed are just too heavy, and I desperate;y wanted flexi to be the answer. Your long list of reoccurring flexi failures has now permanantly cured me of that ..... bugger the weight.

On a positive note, before see you panel removal pics I was concerned about the strength of mounting with polyurethane or polymer adhesives
 
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Drover

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I always was concerned about the heat generated by them, mate used to throw his over bonnet or windscreen and the metal or glass just gets blisteringly hot, he has actually gone to slinging it like a tent fly off van or ute for air flow as worried they would self destruct.
 
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Boots in Action

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Pulled flexible panel off top of van yesterday(mounted to laserlite sheet) and boy, dont muck around with fancy sikkaflex’s, just use good old roof and gutter silicone.
I really struggled to first, pull panel off laserlite and then even harder, pull laserlite off roof.
Anyway, Ive now fitted a 300W glass panel and is charging beautifully.
View attachment 62895
View attachment 62896View attachment 62897

Good luck with the newer GLASS panel/s now @Moto Mech . Just make sure a hail stone bigger than 25mm fallingat terminal velocity does not hit the panel, or a tree branch! You have had more than your share of solar problems!!