Hi All,

As I continue my solar research, I came across the bifacial panel option and I want to sound  board my thinking. 

Traditionally convention dictates a north facing install. Now, as I am installing a Goodwe ES with 2 MPPTs, I was thinking:

- Install 1 string of 4 panels (350-400W) north facing on the roof (traditional racking)

- Install 1 string of 4 panels facing West. This will help optimising production during my peak usage (Western Cape and late sunny evenings) 

BUT - seeing that this will be on a flat roof section, which will then require a tilting racking system I am wondering whether Bifacial panels will not be a great option here as I should then get very good production during the morning when it hit the back of the panel?

(for discussion assume no shading issues)

Secondary question

Can one do 2 west and 2 east on the same string and MPPT? (See snippet from article attached)

Secondary question

Assuming a VMP of 50V, what wire thickness do I need for a string of 4 and 15m cable length. Online calculators give me different answers of 4 and 6 mm2.

 

11 hours ago, daniemare said:

Can one do 2 west and 2 east on the same string and MPPT? (See snippet from article attached)

No. Not in the same string. But when you make 2 strings out of it and parallel them on 1 MPP tracker that's no problem.

Interesting topic, do you have an example of such a panel?

10 hours ago, RikH said:

But when you make 2 strings out of it and parallel them on 1 MPP tracker that's no problem.

That was my intention.

see attached for example

Also full article of idea https://www.ee.co.za/article/bifacial-solar-pv-modules-give-increased-power-output-potential.html#.XncAKyWxUlR

Canadian_Solar-Datasheet-BiKu_CS3K-MB-FG__IEC1500V__v5.57_EN.pdf

Did you end up installing bifacial panels vertically? It's really interesting and I'd love to know how it turned out

I designed and implemented another solution for this Problem. I have what you see in the video in operation for more than a year, working perfectly.

https://youtu.be/lLozeLOEaW4

Bifacial factor for panels available in SA at the moment is around 70 to 80%, but will go up when N Type panels arrive later in the year.

It's an interesting topic and I've been thinking about how I'd test it out at home as well, based on articles I've been seeing about the positive performance of vertical PV systems and Agrivoltaics. You would need to separate your MPPT strings into at least 3 for maximum solar capture: North facing, East facing, West facing. That will allow you to maximise your power output curve. I saw a graph of this yesterday where the vertical mounting gives you a double hump output graph alongside your single hump of the North facing panels.

https://www.pv-magazine.com/2022/07/11/the-stabilizing-effect-of-vertical-east-west-oriented-pv-systems/
 

On 2020/03/21 at 10:21 AM, daniemare said:

Hi All,

As I continue my solar research, I came across the bifacial panel option and I want to sound  board my thinking. 

Traditionally convention dictates a north facing install. Now, as I am installing a Goodwe ES with 2 MPPTs, I was thinking:

- Install 1 string of 4 panels (350-400W) north facing on the roof (traditional racking)

- Install 1 string of 4 panels facing West. This will help optimising production during my peak usage (Western Cape and late sunny evenings) 

BUT - seeing that this will be on a flat roof section, which will then require a tilting racking system I am wondering whether Bifacial panels will not be a great option here as I should then get very good production during the morning when it hit the back of the panel?

(for discussion assume no shading issues)

Secondary question

Can one do 2 west and 2 east on the same string and MPPT? (See snippet from article attached)

Secondary question

Assuming a VMP of 50V, what wire thickness do I need for a string of 4 and 15m cable length. Online calculators give me different answers of 4 and 6 mm2.

 

In the Western Cape those panels not facing North will be extremely ineffecient in Winter.

If anyone has access to Helioscope, could you do a vertical mount model to see what the results are? I'm fascinated by this topic 

12 hours ago, I84RiS said:

In the Western Cape those panels not facing North will be extremely ineffecient in Winter.

can you please elaborate this as I am in process of applying for the building plan approval in the WC where the house is facing east-west side

regards 

Edited August 3, 20223 yr by ibiza

Try a free trial of some solar design software like this, then you'll see what sort of output you can get from a system mounted on your roof. Your architect might even be able to do it for you actually, they should be doing light simulations for your home design anyway.

www.helioscope.com