The calculator allows country and town selection and will calculate optimum panel angle for each month or the year. *NB* the angle it calculates is that from the vertical plane whereas most of us think of the angle from the horizontal plane (the ground) so you must subtract the calculated number from 90 in order to find the angle from the ground.
I did a few calculations for Australia, roughly every 5d of latitude from Melbourne to Darwin as follows (angles are from the ground):
----
Melbourne, -37.8
Nov - Jan Feb - Apr May - July Aug - Oct
14d 38d 62d 38d
Bendigo, -37d
Nov - Jan Feb - Apr May - July Aug - Oct
14d 37d 60d 37d
Port Macquarie, -31d
Nov - Jan Feb - Apr May - July Aug - Oct
8d 31d 54d 31d
Bundaberg, -25d
Nov - Jan Feb - Apr May - July Aug - Oct
2d 25d 48d 25d
Townsville, -19d
Nov - Jan Feb - Apr May - July Aug - Oct
0d 19d 42d 19d
Darwin, -12d
Nov - Jan Feb - Apr May - July Aug - Oct
-12d 12d 36d 12d
----
There is a greater spread of angles that I expected, indeed the support leg for a panel in Bendigo over the year needs to vary between 200mm and 700mm.
It's very hard to find good information on panel losses due to angle but a test done in India suggests around 10%.
I've cut some 200mm legs from fallen branches but next time I'm in Melbourne it's down to Bunnings for 20x10mm box section aluminium in which I can drill a few holes so I can change the panels angle over the year.
Edit: Corrected the link.
-- Edited by Mike Harding on Monday 15th of November 2021 12:15:45 PM
Whenarewethere said
01:05 PM Nov 15, 2021
A styrene rectangular block will provide 3 heights for low angles, weight next to nothing & pack within the folding panels.
Peter_n_Margaret said
02:19 PM Nov 15, 2021
Earlier fixed panels had trackers on them to optimise the angle during the day and from month to month. These days, it is cheaper to simply add additional panels and suffer some inefficiencies. This tracker on a Pilbara cattle station was broken. I fixed the panel position to face north at the best angle.
The first panels I fitted to the OKA had hinges that allowed adjustment. It was too hard and it was easier to simply add another panel.
The effective collection of a panel at the wrong angle is equivalent to the effective area presented to the sun. Flat is typically undesirable because they collect more crap and don't self clean as well when it rains. In Norway we noticed many panels standing vertically facing south. This also stopped the build up of snow.
With the 4x80W portable panels for my previous MH i strapped them on top of 'gear box' on the back for driving. So I made some plywood spacers to protect them. as they evolved they were rectangular, shorter than the panels and as wide as them. I cut notches, so the panel edges would sit into them when angled on the ground. So had some two height props, medium and steeper, using the ply spacers. That worked OK and was probably enough of a variation IMHO.
When we were chasing power i set them steep facing the early east sun, as best as possible, then mid day north flatter, then later to the west steeper. That worked OK if we had the open area to do it. I did have an extension cord for the panels so they could be moved a good distance away if needed. Also a SS cable and locks. Often I just used a fence if there was one around.
Good Luck, Jaahn
Whenarewethere said
03:28 PM Nov 15, 2021
At old Halls Creek, automatic tracking back in the 1970s. A tank on each side painted black, the sun would heat up the tank & make that side lighter & the panel would track the sun.
The cost of panels back then tracking the sun would be worth every watt you gained.
peatop said
01:30 AM Nov 16, 2021
I built my first solar tracker back in the late 80's which use a rotisory grill motor and worked using an LDR to detect the light source.
Watching the YouTube channel offgrid garage the guy on there uses a SPAT lol forget what it means but basically it's a drink can lol you place it on the panel and you move the panel to remove the shadow, simple best to drink the beer before doing the setting or it may become warm
Rob Driver said
10:20 AM Nov 16, 2021
I saw a bloke in a camp with a panel and he had a piece of 3/8 bar fitted on the top of the panel frame.
From memory it extended a few inches above the edge of the panel at right angles and he used to adjust his panel about every hour to ensure that the shadow cast by the rod was just disappearing into the shadow of the panel and frame. He would orient the panel ESE to WNW. We were in North Queensland.
I guess it worked for him otherwise why would he bother.
My experience with solar is what I have had bolted to the roof of the last two vans I have owned. They worked as they should but I dont know of their exact efficiency.
Mike Harding said
12:25 PM Nov 17, 2021
Rob Driver wrote:
My experience with solar is what I have had bolted to the roof of the last two vans I have owned. They worked as they should but I dont know of their exact efficiency.
My caravan, as standard, came with a 120W panel on the roof - I wouldn't say it's useless but I wouldn't say much else about it either.
Until I recently bought 4 x 200W panels I have been using 160W of freestanding panels and having these on a angle and moving them two or three times a day ensured they *far* out-performed the caravan panel.
peatop said
01:44 PM Nov 17, 2021
Although my experience with solar is not limited most of it is old, back when I built my house (off grid) I put my panels on the roof facing north at the recommended angle and just left them at that. I also had a diesel home lighting plant which was demand start and used mainly for washing (2 babies using lots of nappies) so this was run a few days a week also connected to a 50A battery charger so the efficiency of the solar output was not a lot of concern, I guess what I'm saying or trying to say is that the efficiency of your panels is not really the issue until you depend on their output.
If my 2 x 145W panels produce enough power to run my system then do I need to adjust the angles? No. But if it's overcast, raining or cloudy for a few days, what then? do I adjust them or do I just setup more panels? I think to adjust the panels might just use more energy than the return I get from doing so, which would require me to eat and drink more ok that was a joke!
I guess it comes down to do you have the room to store more panels in/on your unit and are you bothered to adjust them several times a day, if you are struggling to get enough charge into your batteries then I guess it then becomes a must do rather than might do. When I was thinking about my off grid setup it was all about generating more power than required so if/when the cloudy days arrive I would have minimal issues, currently I have 2x145W, 1x100W and a 200W blanket (only as backup) I am tempted to buy 2 more of those 145W panels and give the 100W away but at the moment I just don't know that they are needed and hey I can buy more anytime.
Mike Harding said
08:42 AM Nov 18, 2021
peatop wrote:
used mainly for washing (2 babies using lots of nappies)
I wonder how many of today's "Save the Planet" generation know how to wash a nappy...?
peatop said
10:51 PM Nov 18, 2021
Mike Harding wrote:
peatop wrote:
used mainly for washing (2 babies using lots of nappies)
I wonder how many of today's "Save the Planet" generation know how to wash a nappy...?
They just buy disposables no washing needed, but if they do Hmmm I wonder if they use biodegradable soap? lol My spouse asked me if she could buy disposables for when we went shopping my response was why you asking me? which she replied well you want me to use cloth nappies no I want you to be aware of what you use and how the disposal of the waste affects us, as much as I hated disposable (anything) it was ultimately the choice of the user to determine what best suits them and the situation we had to store our rubbish for however long before we did a tip run and I would hate to think what things would look like if disposable nappies were included in that but I did say that it was a good idea to use disposables while out for extended periods as using reusables was not car friendly when away from home upto 12 hrs shopping lol we always tried to find ways to repurpose everything and a trip to the tip was always a retreaval rather than a dump. I built all my machinery from repurposed equipment whenever possible.
But yeah your right, one greenie (and this is what I call them) would collect waxed milk cartons but let them blow around in the wind. another used to use disposables, and let there waste flow down a water course, Im not the best and probably shouldn't pock sticks but it was just funny that they called themselves green when they were red'r than me lol
Called Xpanse Solar Awning there are several sites displaying them other than the one I have pasted here.
The cost given is around $10,000 US dollars and so far I don't know of any being imported into Australia. But once someone introduces something others will also start one cheaper and better.
The main advantage I can see is that the van roof is kept free. Other advantages are easy storage and higher output. The main disadvantage is that it is not waterproof (at this time).
Pete, was yours a pre order special at maybe $500 ?
Tony LEE said
09:24 PM Dec 9, 2021
The makers of the panels I have just installed on the Volvo have solved the water pooling problem on panels mounted flat. They cut a small channel across the frame on each corner - works perfectly.
Can also get plastic clips that fit on each corner that supposedly drain the water by capilliary action
Recent threads got me thinking about solar panel directions and angles so I've done a little research and this is a good site for data:
Solar panel angles calculator
The calculator allows country and town selection and will calculate optimum panel angle for each month or the year. *NB* the angle it calculates is that from the vertical plane whereas most of us think of the angle from the horizontal plane (the ground) so you must subtract the calculated number from 90 in order to find the angle from the ground.
I did a few calculations for Australia, roughly every 5d of latitude from Melbourne to Darwin as follows (angles are from the ground):
----
Melbourne, -37.8
Nov - Jan Feb - Apr May - July Aug - Oct
14d 38d 62d 38d
Bendigo, -37d
Nov - Jan Feb - Apr May - July Aug - Oct
14d 37d 60d 37d
Port Macquarie, -31d
Nov - Jan Feb - Apr May - July Aug - Oct
8d 31d 54d 31d
Bundaberg, -25d
Nov - Jan Feb - Apr May - July Aug - Oct
2d 25d 48d 25d
Townsville, -19d
Nov - Jan Feb - Apr May - July Aug - Oct
0d 19d 42d 19d
Darwin, -12d
Nov - Jan Feb - Apr May - July Aug - Oct
-12d 12d 36d 12d
----
There is a greater spread of angles that I expected, indeed the support leg for a panel in Bendigo over the year needs to vary between 200mm and 700mm.
It's very hard to find good information on panel losses due to angle but a test done in India suggests around 10%.
I've cut some 200mm legs from fallen branches but next time I'm in Melbourne it's down to Bunnings for 20x10mm box section aluminium in which I can drill a few holes so I can change the panels angle over the year.
Edit: Corrected the link.
-- Edited by Mike Harding on Monday 15th of November 2021 12:15:45 PM
A styrene rectangular block will provide 3 heights for low angles, weight next to nothing & pack within the folding panels.
Earlier fixed panels had trackers on them to optimise the angle during the day and from month to month.
These days, it is cheaper to simply add additional panels and suffer some inefficiencies.
This tracker on a Pilbara cattle station was broken. I fixed the panel position to face north at the best angle.
The first panels I fitted to the OKA had hinges that allowed adjustment. It was too hard and it was easier to simply add another panel.
The effective collection of a panel at the wrong angle is equivalent to the effective area presented to the sun.
Flat is typically undesirable because they collect more crap and don't self clean as well when it rains. In Norway we noticed many panels standing vertically facing south. This also stopped the build up of snow.
Cheers,
Peter
Hi Mike
With the 4x80W portable panels for my previous MH i strapped them on top of 'gear box' on the back for driving. So I made some plywood spacers to protect them. as they evolved they were rectangular, shorter than the panels and as wide as them. I cut notches, so the panel edges would sit into them when angled on the ground. So had some two height props, medium and steeper, using the ply spacers. That worked OK and was probably enough of a variation IMHO.
When we were chasing power i set them steep facing the early east sun, as best as possible, then mid day north flatter, then later to the west steeper. That worked OK if we had the open area to do it. I did have an extension cord for the panels so they could be moved a good distance away if needed. Also a SS cable and locks. Often I just used a fence if there was one around.
Good Luck, Jaahn
At old Halls Creek, automatic tracking back in the 1970s. A tank on each side painted black, the sun would heat up the tank & make that side lighter & the panel would track the sun.
The cost of panels back then tracking the sun would be worth every watt you gained.
I built my first solar tracker back in the late 80's which use a rotisory grill motor and worked using an LDR to detect the light source.
Watching the YouTube channel offgrid garage the guy on there uses a SPAT lol forget what it means but basically it's a drink can lol you place it on the panel and you move the panel to remove the shadow, simple
best to drink the beer before doing the setting or it may become warm 
From memory it extended a few inches above the edge of the panel at right angles and he used to adjust his panel about every hour to ensure that the shadow cast by the rod was just disappearing into the shadow of the panel and frame. He would orient the panel ESE to WNW. We were in North Queensland.
I guess it worked for him otherwise why would he bother.
My experience with solar is what I have had bolted to the roof of the last two vans I have owned. They worked as they should but I dont know of their exact efficiency.
My caravan, as standard, came with a 120W panel on the roof - I wouldn't say it's useless but I wouldn't say much else about it either.
Until I recently bought 4 x 200W panels I have been using 160W of freestanding panels and having these on a angle and moving them two or three times a day ensured they *far* out-performed the caravan panel.
Although my experience with solar is not limited most of it is old, back when I built my house (off grid) I put my panels on the roof facing north at the recommended angle and just left them at that. I also had a diesel home lighting plant which was demand start and used mainly for washing (2 babies using lots of nappies) so this was run a few days a week also connected to a 50A battery charger so the efficiency of the solar output was not a lot of concern, I guess what I'm saying or trying to say is that the efficiency of your panels is not really the issue until you depend on their output.
If my 2 x 145W panels produce enough power to run my system then do I need to adjust the angles? No. But if it's overcast, raining or cloudy for a few days, what then? do I adjust them or do I just setup more panels? I think to adjust the panels might just use more energy than the return I get from doing so, which would require me to eat and drink more
ok that was a joke!
I guess it comes down to do you have the room to store more panels in/on your unit and are you bothered to adjust them several times a day, if you are struggling to get enough charge into your batteries then I guess it then becomes a must do rather than might do. When I was thinking about my off grid setup it was all about generating more power than required so if/when the cloudy days arrive I would have minimal issues, currently I have 2x145W, 1x100W and a 200W blanket (only as backup) I am tempted to buy 2 more of those 145W panels and give the 100W away but at the moment I just don't know that they are needed and hey I can buy more anytime.
I wonder how many of today's "Save the Planet" generation know how to wash a nappy...?
They just buy disposables no washing needed, but if they do Hmmm I wonder if they use biodegradable soap? lol My spouse asked me if she could buy disposables for when we went shopping
my response was why you asking me? which she replied well you want me to use cloth nappies 
no I want you to be aware of what you use and how the disposal of the waste affects us, as much as I hated disposable (anything) it was ultimately the choice of the user to determine what best suits them and the situation 
we had to store our rubbish for however long before we did a tip run and I would hate to think what things would look like if disposable nappies were included in that 
but I did say that it was a good idea to use disposables while out for extended periods as using reusables was not car friendly when away from home upto 12 hrs shopping lol we always tried to find ways to repurpose everything and a trip to the tip was always a retreaval rather than a dump. I built all my machinery from repurposed equipment whenever possible.
But yeah your right, one greenie (and this is what I call them) would collect waxed milk cartons but let them blow around in the wind. another used to use disposables, and let there waste flow down a water course, Im not the best and probably shouldn't pock sticks but it was just funny that they called themselves green when they were red'r than me lol
Just noticed this on the Internet.
https://www.motor1.com/news/545603/rv-awning-solar-panels/
Called Xpanse Solar Awning there are several sites displaying them other than the one I have pasted here.
The cost given is around $10,000 US dollars and so far I don't know of any being imported into Australia. But once someone introduces something others will also start one cheaper and better.
The main advantage I can see is that the van roof is kept free. Other advantages are easy storage and higher output. The main disadvantage is that it is not waterproof (at this time).
Murray
I have a mini version :)
Works when down too.....
Cheers,
Peter