Comparing Solar Power In Summer And Winter ..........

Tilting as said makes a significant difference to what can be produced assuming soc of battery actually needs it.
This is mine in Winter mode and the current on that particular day increased by about 500%.

In a Finland the sun is so low they mount their panels on the sides of their houses rather than on the roof
Do you have to climb up to adjust your panel ?
 
Very interesting thread. Thanks for posting Colin.
Out of interest when angling the solar panel could you use mirror deflection on to the solar panel to enhance performance? Has anyone tried this?
Cheers. David.

The idea works and you'll occasionally see this kind of set up, David.
The main problem is that the mirrors need to be moveable in order that, when reflecting sunlight onto the solar panel at one time of the day, they are not shading the solar panel at another time of the day.
In the UK, for instance, in order to reflect sunlight onto the panel in the morning the mirror needs to be sloping up from the horizontal on the west side of the panel and facing east. That means that later in the day as the sun is in the west, the mirror is shading the solar panel.
Now that the cost of solar panels is falling rapidly, it's generally considered more cost effective to install more panels than mirrors - unless the installation is highly specialised and there is no other technical solution.
There's a huge system using mirrors in Spain where an enormous array of steerable mirrors focus sunlight onto a 'furnace' on a tower. It can be seen from kilometres away and as I cycled past it some years ago I was astounded by it:


It should always be remembered that adding any technological complexity (e.g. moving parts, actuators, electronics) to a system adds cost, extends pay-back time, reduces reliability, increases weight etc, etc.
This applies to the system in Spain as much as it does to tilting solar panels on Mohos. It may be worth doing on a Moho if there's no other solution (for instance the power requirement cannot be reduced and/or there isn't sufficient space for static solar panels).

Colin 🙂🙂🙂
 
Last edited:
I think the sun here in Dorset only gets to about 62* elevation. So if the sun rises from ~0* and climbs to 62*, why would you mount a solar panel horizontally? Is 31* from vertical better?
 
I started this thread because I thought it would be interesting to compare a theoretical consideration of winter/summer solar panel output with the anecdotal advice often given for the UK. I then extended this for winter/summer solar panel output at various latitudes.
The thread has now expanded somewhat and my feeling is that I have little else to contribute to the current discussion.
I'll therefore drop out now and leave you guys to enjoy the thread in your own way.
On balance I'm pleased with the feedback on post #1 so when I get time I'll have a go at extending the work I initially posted.

Colin :):):)
 
I started this thread because I thought it would be interesting to compare a theoretical consideration of winter/summer solar panel output with the anecdotal advice often given for the UK. I then extended this for winter/summer solar panel output at various latitudes.
The thread has now expanded somewhat and my feeling is that I have little else to contribute to the current discussion.
I'll therefore drop out now and leave you guys to enjoy the thread in your own way.
On balance I'm pleased with the feedback on post #1 so when I get time I'll have a go at extending the work I initially posted.

Colin :):):)

Colin,
It was a great idea of yours and from what has been said in the replies hopefully it makes others think.
 
How many watts of panel do you have?
I have six 100watt panels, but since adding the last two each side of a roof hatch it’s become very directional. They are connected in series down each side then paralleled. So if one is in shadow I loose the string. Another charge controller would sort it out, but Murky is destined for sale. The Betty build has six panels in pairs, each pair having their own controller.
 
Any recommendations on solar panels? Or, of course, brands to avoid?

I installed a 300W Panasonic solar panel with Victron control and display equipment about two years ago and am delighted with the performance.
It's not cheap but my view is that I only want to do this once and I want the installation to be 'fit and forget' - and that's what it's been.

Colin :):):)
 
Fascinating. Yet to get any panels, which we never did when we lived on a narrowboat either. This whole conversation has been most useful & I will follow it up.

Ian
 
Any recommendations on solar panels? Or, of course, brands to avoid?
The general recommedation I would make is unless you have an overwhelming reason to fit flexible panels, don't! Stay with glass panels.
After that point, work out what size (physically) you want/can install and then see what is available in that size. For example, in the sizes that will fit on my roof where I want to install, I have found Victron Panels the only ones that will maximize the roof space in my particular case (800mm x 2000mm)
 
I have a flexible 140watt. I chose that as it was lighter and at the time of fitting not that much more than a glass version. I also thought I could remove it and use it on the side of the M/H if I wanted. It gave me an easy option to move around, It was before tilting them became the fashion.
 
Last edited:
I’m going to get a couple of 100 watt semi flexible panels to mount on the side with suction cups. These will have their own mppt controller.
 

Users who viewed this discussion (Total:0)

Back
Top