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

[jagmanx]

I must keep up . Thanks
So a flat panel works ok in summer. Tick /

Yes !

 

[xsilvergs]

I must keep up . Thanks
So a flat panel works ok in summer. Tick /

Possibly not at full power and not all day.

How long was your 'Longest Day'?

Today (June 21st) is meant to be the longest day, and curious to know how long your own Solar Harvesting day was? For those who can tell (e.g. @St3v3 , @RAW and maybe others), post the time your MPPT Controller turned on this morning and went off this evening - and your location (to get an...

motorhomer.com

 

[SquirrellCook]

If you’re really worried about the inclination of your solar panels and you don’t want to spend lots of money. Just put all the packing you can find under the tyres on one side of your van to lean it towards the sun. There will be other problems to address, but now you’re expecting to much!

 

[Exwindsurfer]

Like you say Rae it makes a big differance.

 

[jagmanx]

Yess tilting will make a big difference especially in winter...
You may also benifit from a 3 position strategy. regarding horizontal orientation

• facing SE in Morning
• Due south middle of the day
• SW later in the evening

In the depths of winter the orientation will not be of much extra benefit but if the sun angle is low eg 25 deg....try to get the panels at 65 deg.
Yes the spraycan method works AKA a sundial

 

[jagmanx]

Yes that is good. And as you say if overcast dropping the panels is effective as the solar energy is not as much like a point source.

 

[wildebus]

Here is a bit of info folks on this thread might find interesting?

So the graphs below show the sunlight level at the English-Scottish Eastern Border in the last year, showing irradiation and UV Levels.
This should tell you what you could expect to harvest on your solar panels when angled and facing south (like the little panel on my weather station is). This is bearing in mind that the Wattage quoted for a panel assumes a irradiation level of 1000watts/m2 received (so less than that, less power; more, more power. Ignoring heat effects on PV Panels)

This is for the week following the longest day in 2020


And similarly, the week following the shortest day in 2019


A rather big difference!
The combination of a greatly reduced level of Solar Radiation, combined with a significantly shortened Solar Day means PV Harvesting in winter is dramatically curtailed*

*waste of time?

 

[Full Member]

Here is a bit of info folks on this thread might find interesting?

So the graphs below show the sunlight level at the English-Scottish Eastern Border in the last year, showing irradiation and UV Levels.
This should tell you what you could expect to harvest on your solar panels when angled and facing south (like the little panel on my weather station is). This is bearing in mind that the Wattage quoted for a panel assumes a irradiation level of 1000watts/m2 received (so less than that, less power; more, more power. Ignoring heat effects on PV Panels)

This is for the week following the longest day in 2020
View attachment 56617

And similarly, the week following the shortest day in 2019
View attachment 56618

A rather big difference!
The combination of a greatly reduced level of Solar Radiation, combined with a significantly shortened Solar Day means PV Harvesting in winter is dramatically curtailed*

*waste of time?

Thanks David, that's very useful information.
I guess the data is from about latitude 55.6° ? And the panel is facing south at a fixed angle of about 35° to the horizontal?

Colin

 

[wildebus]

Thanks David, that's very useful information.
I guess the data is from about latitude 55.6° ? And the panel is facing south at a fixed angle of about 35° to the horizontal?

Colin

Good Guess
Station is located at Location is 55.65 °N ; And Elevation is 161 ft (so closer to the sun than at sea level )
Not checked the angle, but looks maybe a bit more angled? It is fixed however, so doesn't compensate for time of year.
I am sure that if the solar panels on the Motorhome/Campervan were flat the difference between summer and winter would be larger than in those graphs with the lower sun

 

[Clunegapyears]

Being a technical numpty ... I got several things from Colin's post ...
Not all sun is equal. Can now understand why we weren't replenishing batteries as well as Scotland compare to down south!
Marrakesh is desirable but not wanting to get stuck over there, unrealistic.
Thank you

 

[nabsim]

Can I mention the G word?

 

[Exwindsurfer]

Can I mention the G word?

NO lolol

 

[nabsim]

NO lolol

Notice how I asked first though lol

 

[Geraldine]

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.

 

[Exwindsurfer]

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.

David i think it would be much easier to tilt the panels lolol

 

[Wully]

There are some Really clever people on here I’ve just read this all the way through wow ma heeds pickled. But not as much as Colin’s when I ask him to work this one out what if there are two suns...1..2 should keep you Busy for a while. More pencils please. Joking aside I’m impressed with the work you’ve put into this subject.

 

[CriftinsCampers]

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

 

[xsilvergs]

Due to the low elevation of the sun for most of the year, here in the UK, I have consider mounting panels to the sides of the trailer.

 

[Exwindsurfer]

Don’t understand why more people don’t tilt them

 

[xsilvergs]