Solar panel positioning

[Higgs]

 

[doratheexplorer]

2 minutes ago, Alan de Enfield said:

 

Bimble are now selling similar panels to the ones I bought some years ago (but 110v instead of 120v and 165w instead of 170w)  but they are still being called 'low light' panels

 

Solar Frontier BLACK 165W CIS solar panel - higher performance in low light - No Shading Issues - SF165 - Very Rare - Last Stock in Europe - Very Limited Stocks - MPPT with input 110v above only (bimblesolar.com)

 

These panels do not have shading issues like other panels.  Shade only affects the actual amount shaded, unlike crystalline panel.  Great for boats or campers where partial shading can often happen.

These CIS thin film panels out perform Crystalline panels in lower light levels.  We have done side by side tests in winter and found that with winter sun these panels will give a decent about of additional power over crystalline panels.  In cloudy conditions they both perform the same, with very low output, but then the low powered winter sun does shine the CIS panels out perform the crystalline panels with upto double the power from the same sized array. 

 

 

 

 

Now you know, you can challenge Bimble with the 'science' if you are inclined.

I can totally see how a panel's structure might work better when the sunlight is at a low angle.  It's not quite the same as 'low' light though.  For example, if you're moored under trees, there's no getting around that.

[Alan de Enfield]

25 minutes ago, doratheexplorer said:

I can totally see how a panel's structure might work better when the sunlight is at a low angle.  It's not quite the same as 'low' light though.  For example, if you're moored under trees, there's no getting around that.

 

 

Sorry, I thought I had explained that in my previous post :

 

I was fortunate to stumble on some panels that Bimble had for sale that were designed for 'high latitudes' in Scandinavia and were called 'low-light' panels as they were designed (not for low light levels) for low angles of incidence so they produce a better output in Spring / Autumn when the Sun is low in the sky.

 

This is again reinforced by the info I have just posted (above) from Bimble :

 

These panels do not have shading issues like other panels.  Shade only affects the actual amount shaded, unlike crystalline panel.  Great for boats or campers where partial shading can often happen.

These CIS thin film panels out perform Crystalline panels in lower light levels.  We have done side by side tests in winter and found that with winter sun these panels will give a decent about of additional power over crystalline panels.  In cloudy conditions they both perform the same, with very low output, but when the low powered winter sun does shine the CIS panels out perform the crystalline panels with upto double the power from the same sized array. 

 

More technical Info on CIS panels :

 

What is CIS? (solar-frontier.eu)

 

The higher energy yield compared with conventional crystalline silicon modules is one of a number of significant advantages offered by the Solar Frontier PowerModules. Solar Frontier’s CIS technology is also more efficient than other thin-film modules such as tandem, amorphous or microamorphous modules.

Many model calculations for solar power installations based on conventional module technologies assume optimum conditions, with the sun high in the sky, no clouds, a clear atmosphere, no shadows, moderate temperatures. But for how many hours in a year are these conditions really present? With the CIS PowerModules from Solar Frontier higher power yields can be obtained more than with rival products, even in shadow, under cloudy skies, low light or high temperatures – thanks to the remarkable properties of CIS technology:

 

Another advantage, not only in comparison with crystalline modules but also with other-thin film technologies, such as cadmium tellurite, is the low environmental impact of CIS technology. Solar Frontier modules are free from lead and cadmium, and thus satisfy the requirements of the Restriction of Hazardous Substances (RoHS) directive. The substantially lower percentage of raw materials required for manufacturing Solar Frontier’s CIS PowerModules highlights the more environmentally friendly nature of the technology and its production processes. 

 

 

 

 

Highest yields – even with foggy outlook.

Mornings, evenings, fog, diffuse light, overcast skies – the sun rarely shines full force. And yet, it is precisely in the midst of these daily adversities that, thanks to their good low-light performance, the CIS PowerModules by Solar Frontier produce more power than others.

The spectral irradiation power density changes with the Air Mass factor (AM). The Air Mass factor corresponds with the distance the sunlight has to travel through the Earth’s atmosphere: AM = 1 means vertical irradiation of the Earth’s surface (midday at the equator), AM >> 1 means a low angle of incidence (sunrise or sunset). As  AM increases, the absolute value of irradiation intensity increases, but at the same time the energy shifts towards longer wavelengths (sunrise and sunset-red).

As Solar Fontier’s CIS technology has much higher sensitivity for these longer wavelengths, even reaching the infrared bandwidth, the relative energy yield of Solar Frontier’s CIS modules at this time of the day is much higher. This is particularly advantageous in the early morning and the late evening hours. Also in misty weather, in the case of clouds or contamination this property of CIS modules proves its value, resulting in significantly higher output levels than other technologies. 

 

Good low-light behaviour (solar-frontier.eu)

 

 

 

Highest yields – even in the shade.

Thanks to their high shadow tolerance, PowerModules are very efficient even when shadows are cast over the modules or their surfaces are partly covered.

The reason for this can be found in the different cellular structure. The square silicon cells in the module are connected in substrings. On the other hand, the long, very narrow thin-film cells are connected in series.

 

 

The entire c-Si module stops working as soon as a small area, a single cell, for example, is covered or shadowed. In contrast, the CIS module continues working, only the covered or shaded area stops producing energy. The results are higher yields even in the shade.

This has the advantage that some shadowing is acceptable in designing the system, in order to achieve the highest yields. If defined shadows are to be expected, (for example: horizontal shadows in the morning or evening cast by a shed roof, or in a field system), then energy production can be optimized: in this case, the CIS modules must be installed with the cell perpendicular to the cast of the shadow. If shadowing of a module or a module row of x% occurs, there is still energy production of 100-X%.

The cell structure of the modules and the associated shadow tolerance has the added advantage that the distance between module rows can be reduced in free-field installations and on industrial flat rooftops, so more generating power, expressed in Watt-peak, can fit in a given area.

Edited May 13, 2021 by Alan de Enfield

[doratheexplorer]

1 hour ago, Alan de Enfield said:

 

 

Sorry, I thought I had explained that in my previous post :

You had.  I was just agreeing with you.  Scary, I know.

[IanD]

1 hour ago, Alan de Enfield said:

 

 

Sorry, I thought I had explained that in my previous post :

 

I was fortunate to stumble on some panels that Bimble had for sale that were designed for 'high latitudes' in Scandinavia and were called 'low-light' panels as they were designed (not for low light levels) for low angles of incidence so they produce a better output in Spring / Autumn when the Sun is low in the sky.

 

This is again reinforced by the info I have just posted (above) from Bimble :

 

These panels do not have shading issues like other panels.  Shade only affects the actual amount shaded, unlike crystalline panel.  Great for boats or campers where partial shading can often happen.

These CIS thin film panels out perform Crystalline panels in lower light levels.  We have done side by side tests in winter and found that with winter sun these panels will give a decent about of additional power over crystalline panels.  In cloudy conditions they both perform the same, with very low output, but when the low powered winter sun does shine the CIS panels out perform the crystalline panels with upto double the power from the same sized array. 

 

More technical Info on CIS panels :

 

What is CIS? (solar-frontier.eu)

 

The higher energy yield compared with conventional crystalline silicon modules is one of a number of significant advantages offered by the Solar Frontier PowerModules. Solar Frontier’s CIS technology is also more efficient than other thin-film modules such as tandem, amorphous or microamorphous modules.

Many model calculations for solar power installations based on conventional module technologies assume optimum conditions, with the sun high in the sky, no clouds, a clear atmosphere, no shadows, moderate temperatures. But for how many hours in a year are these conditions really present? With the CIS PowerModules from Solar Frontier higher power yields can be obtained more than with rival products, even in shadow, under cloudy skies, low light or high temperatures – thanks to the remarkable properties of CIS technology:

 

Another advantage, not only in comparison with crystalline modules but also with other-thin film technologies, such as cadmium tellurite, is the low environmental impact of CIS technology. Solar Frontier modules are free from lead and cadmium, and thus satisfy the requirements of the Restriction of Hazardous Substances (RoHS) directive. The substantially lower percentage of raw materials required for manufacturing Solar Frontier’s CIS PowerModules highlights the more environmentally friendly nature of the technology and its production processes. 

 

 

 

 

Highest yields – even with foggy outlook.

Mornings, evenings, fog, diffuse light, overcast skies – the sun rarely shines full force. And yet, it is precisely in the midst of these daily adversities that, thanks to their good low-light performance, the CIS PowerModules by Solar Frontier produce more power than others.

The spectral irradiation power density changes with the Air Mass factor (AM). The Air Mass factor corresponds with the distance the sunlight has to travel through the Earth’s atmosphere: AM = 1 means vertical irradiation of the Earth’s surface (midday at the equator), AM >> 1 means a low angle of incidence (sunrise or sunset). As  AM increases, the absolute value of irradiation intensity increases, but at the same time the energy shifts towards longer wavelengths (sunrise and sunset-red).

As Solar Fontier’s CIS technology has much higher sensitivity for these longer wavelengths, even reaching the infrared bandwidth, the relative energy yield of Solar Frontier’s CIS modules at this time of the day is much higher. This is particularly advantageous in the early morning and the late evening hours. Also in misty weather, in the case of clouds or contamination this property of CIS modules proves its value, resulting in significantly higher output levels than other technologies. 

 

Good low-light behaviour (solar-frontier.eu)

 

 

 

Highest yields – even in the shade.

Thanks to their high shadow tolerance, PowerModules are very efficient even when shadows are cast over the modules or their surfaces are partly covered.

The reason for this can be found in the different cellular structure. The square silicon cells in the module are connected in substrings. On the other hand, the long, very narrow thin-film cells are connected in series.

 

 

The entire c-Si module stops working as soon as a small area, a single cell, for example, is covered or shadowed. In contrast, the CIS module continues working, only the covered or shaded area stops producing energy. The results are higher yields even in the shade.

This has the advantage that some shadowing is acceptable in designing the system, in order to achieve the highest yields. If defined shadows are to be expected, (for example: horizontal shadows in the morning or evening cast by a shed roof, or in a field system), then energy production can be optimized: in this case, the CIS modules must be installed with the cell perpendicular to the cast of the shadow. If shadowing of a module or a module row of x% occurs, there is still energy production of 100-X%.

The cell structure of the modules and the associated shadow tolerance has the added advantage that the distance between module rows can be reduced in free-field installations and on industrial flat rooftops, so more generating power, expressed in Watt-peak, can fit in a given area.

So they have extra diodes in to help when the panel is partially shaded -- well, so do many other panels nowadays, nothing special about that. Higgs' "Series vs. parallel" link makes exactly the same point, but shading is nothing to do with having "higher output at lower light levels" which is physically impossible -- unless the panel resistance is high (rubbish panel) so the output drops at high light levels, which makes them even worse compared to conventional mono panels.

 

"These CIS thin film panels out perform Crystalline panels in lower light levels." -- which they do, compared to flexible panels without diodes which have lousy efficiency. You can make anything look good by comparing it to something which is rubbish to start off with, it's a standard marketing tactic. If they do have better response for long wavelengths in autumn/winter then they also have poorer response to short ones in summer, otherwise the overall efficiency would be higher -- and it's not, its lower...

 

"Solar Frontier’s new SF165 module offers the highest conversion efficiency of any mass-produced thin-film module - up to 13.8%." Which means that's the *best* efficiency they can offer. And they cost 125 quid for 165W.

 

So let's compare them to a conventional "not-special-low-light" mono panel, like this:

 

https://www.bimblesolar.com/solar/large-panels/380W-JA-solar

 

20.3% efficient, "low shading effect" (meaning, smaller panels and added diodes), 135 quid for 380W.

 

In other words, all the "low-light" claims are marketing BS, a conventional modern mono panel is cheaper and higher output at all light levels (panel output power is pretty much proportional to incident light in all panels). Which explains *why* these are the "last stock in Europe"...

 

Before arguing further, go and do some research, I'm not going to bother repeating the same *facts* (as opposed to marketing BS) again... ?

Edited May 13, 2021 by IanD

[IanD]

Conclusion for boats : flat-mounted high-output mono panels like these are the best bet for high output and bang-for-the-buck:

 

https://www.bimblesolar.com/solar/large-panels/380W-JA-solar

 

If you have lots of them, consider how to connect them for the best immunity to partial shading -- some ways are better if a whole panel is shaded, others if part of all the panels is shaded. YMMV.

Edited May 13, 2021 by IanD