solar panel - Page 2 - Motorhome Forums, Motorhome Discussion, Motorhome Chat

User Tag List

 5Likes
Reply
 
LinkBack Thread Tools
post #11 of 20 (permalink) Old 13-01-2019, 09:54
EJB
Senior Member
 
EJB's Avatar
 
Join Date: Aug 2007
Location: Suffolk (By choice)
My Motorhome: Burstner Nexxo t620G
Posts: 4,269
Thanks: 33
Thanked 136 Times in 126 Posts
This is the best real world example of solar panel efficiency on motorhomes I have seen.
It gives figures as a percent so very easy to adjust to any particular installation.

It compares two motorhome setups:-

https://motorhomer.com/threads/admin...hootout.37952/

Ted.
I try and state simple facts in a nice way.
EJB is offline  
Sponsored Links
Advertisement
 
post #12 of 20 (permalink) Old 13-01-2019, 10:15
Senior Member
 
Mrplodd's Avatar
 
Join Date: Mar 2008
Location: Weymouth
My Motorhome: A Caravan of all things !!
Posts: 9,430
Thanks: 116
Thanked 535 Times in 456 Posts
Quote:
Originally Posted by EJB View Post
This is the best real world example of solar panel efficiency on motorhomes I have seen.
It gives figures as a percent so very easy to adjust to any particular installation.

It compares two motorhome setups:-

https://motorhomer.com/threads/admin...hootout.37952/
The thing to remember about the information in the above link is that firstly both vehicles have pretty substantial solar panel arrays fitted and secondly, and MUCH more importantly, the panels were angled so the sunlight fell as near as vertically on them.

In the “real” world situation we live in MH solar panels are flat on the roof, so sunlight falls on them at a VERY oblique angle during the winter months.

My house panels are at about 30° and on a sunny day I can (and frequently do) watch their output increase as the sun rises in the sky and the sunlight falls at a decreasingly oblique angle. At this time of year, even in bright sunlight their peak output is substantially less (like 50% less) due to the low angle of the sun (as well as many less hours of it of course)

To go back to original question a 25w panel would possibly produce 25w at mid day on the equator. In winter in England, even in bright sunshine?? Bugger all

Andy

Its not the destination that matters.

It's who you share the journey with (even if like me, it’s in a caravan!)
I am very fortunate to have Mrs Plodd to share mine with
Mrplodd is offline  
post #13 of 20 (permalink) Old 13-01-2019, 12:45
EJB
Senior Member
 
EJB's Avatar
 
Join Date: Aug 2007
Location: Suffolk (By choice)
My Motorhome: Burstner Nexxo t620G
Posts: 4,269
Thanks: 33
Thanked 136 Times in 126 Posts
Andy one vehicle has fixed (flat) panels!

Ted.
I try and state simple facts in a nice way.
EJB is offline  
 
post #14 of 20 (permalink) Old 13-01-2019, 13:04
Senior Member
 
powerplus's Avatar
 
Join Date: Oct 2014
Location: berkshire
My Motorhome: swift sundance 620fb
Posts: 1,277
Thanks: 11
Thanked 129 Times in 123 Posts
hi

i have just been playing with my solar here in the algarve

the sun is bright but quite low in the sky my 100w panels are each giving around 2a each with all the lighting in the van switched on

i have seen them up around 5.5a when the sun is a lot higher later in the spring

so answering the original question would a 25w panel be enough well if it was used here i would expect it to be giving around 0.5a at the moment and that is with nice and clear sky

barry
powerplus is offline  
post #15 of 20 (permalink) Old 13-01-2019, 15:14
Senior Member
 
JanHank's Avatar
 
Join Date: Mar 2015
Location: East Germany, I can see Poland from my windows.
My Motorhome: I drive...Auto Trail Navajo
Posts: 12,288
Thanks: 493
Thanked 643 Times in 585 Posts
Personal Aire
You do know your talking amongst yourselves again don't you.
Penquin likes this.

I'm Jan
We learn something new every day.
JanHank is online now  
post #16 of 20 (permalink) Old 13-01-2019, 15:25
Senior Member
 
Penquin's Avatar
 
Join Date: Oct 2007
Location: Aquitaine
My Motorhome: Swift Kontiki 615
Posts: 20,918
Thanks: 935
Thanked 810 Times in 725 Posts
Personal Aire
Hi Barry,

One other thing that would need to be factored in is the angle of incidence of the sun on the panel - this is indicated by the latitude - the measurement north of the Equator. At the Equator the angle of incidence of the sun's rays would be 90 degrees at noon.

In the U.K. where the latitude is around 55 degrees north the incidence at noon would be 25 degrees whereas in Portugal (assumed latitude 39 degrees) it would be 51 degrees. In other words more of the sun's energy will enter the solar panel in Portugal than in the U.K. That reduction in the input is why Portugal feels comfortably warm at present whereas the U.K. is decidedly cool....

So your possible 0.5amp output is likely to be reduced by around half.... so 0.25 amp in the U.K. at noon (if that is when your input was measured).

Or as Paul Daniels used to say "Not a lot"....

.

Any typo that I make means the errorists win.

Any comments above are only MY OPINION and should be read as that.

http://www.leslezards.co.uk
Penquin is online now  
post #17 of 20 (permalink) Old 13-01-2019, 17:24
Senior Member
 
Pudsey_Bear's Avatar
 
Join Date: Sep 2008
Location: Keighley, Still in Gods County.
My Motorhome: 2002 Bessacarr E745.
Posts: 37,553
Thanks: 1,534
Thanked 973 Times in 913 Posts
Send a message via AIM to Pudsey_Bear Send a message via Yahoo to Pudsey_Bear
Quote:
Originally Posted by JanHank View Post
You do know your talking amongst yourselves again don't you.

Stop pointing out everyone's mistakes and errors, it's very annoying after a while.

This thread is interesting on a technical level, repetition isn't a problem if it was all forums would have about 100 posts to cover every subject, job done, close it down to new members.

Now!! don't you have a cake to burn or something Gerty
Pudsey_Bear is offline  
post #18 of 20 (permalink) Old 13-01-2019, 17:48
Senior Member
 
powerplus's Avatar
 
Join Date: Oct 2014
Location: berkshire
My Motorhome: swift sundance 620fb
Posts: 1,277
Thanks: 11
Thanked 129 Times in 123 Posts
hi

penguin

i do agree with you and youdid explain it so much better

i did say i was in the algarve and the sky was nice and clear but i forgot to say that in the uk it would not work so well as the sun would
be even lower

i suppose a 25w panel in the hight of the summer and pointed directly at the sun might possibly give around 15 to 20w but in the uk
i think a bigger panel might be a better option


barry
powerplus is offline  
post #19 of 20 (permalink) Old 13-01-2019, 22:36
Senior Member
 
Join Date: Jun 2007
Location: Belfast
My Motorhome: Hymer Exsis-i 504
Posts: 9,145
Thanks: 193
Thanked 482 Times in 458 Posts
Quote:
Originally Posted by raynipper View Post
They sell small dash solar battery maintainers for about £30 to £40 but only 25w.
These are usually pretty ineffective unless full sun all and every day. At best they might just keep a disconnected battery maintained.


Ray.
I know I'm rubbish at electrics Ray but I'm struggling to figure how a disconnected battery could be maintained?!?

Jean
jiwawa is offline  
post #20 of 20 (permalink) Old 13-01-2019, 22:36
Senior Member
 
Join Date: Jun 2007
Location: Belfast
My Motorhome: Hymer Exsis-i 504
Posts: 9,145
Thanks: 193
Thanked 482 Times in 458 Posts
Ah, sorry.... Disconnected from any load....
raynipper likes this.

Jean
jiwawa is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Motorhome Forums, Motorhome Discussion, Motorhome Chat forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in










Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page



Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome