Reflection of the sun's rays

[frankz66]

Hi everyone, I wanted to have some advice on the arrangement of the solar panels. Coe from attached my panels are facing south evenly, producing during the day in a constant way. I noticed that in the late afternoon around 17 pm, the sun goes in the direction of the sunset, so it lowers intensely irradiating the first 4 panels and a little less the other 4 panels to follow. The red arrow roughly indicates the direction of the sun's rays and I realized that being inclined by force of things, nothing can be done. I write this, because at 17 pm I see that the power of the regulator fluctuates slightly from 190 w to 250 w. Moreover, in that precise moment for about 15 minutes I find myself a very slight oscillating shadow due to the presence of a palm tree. If you look closely at the photo we are talking about small darkenings for a few ten minutes ... Being 8 panels 2s2p then the first 4 in series and to follow the second four to follow and then go down to the regulator in parallel. I wanted to have your opinion, whether it is appropriate to configure the blocking diodes or not. Finally, I wanted to point out that in the morning the opposite phase happens, the sun rises in the east, so the situation is reversed, the first four due to the inclination of the sun are radiated a little more than the others. I think all this is normal, but I still wanted your opinion. The panels have a total of 1450 kwp, they work well and I have also seen from the software monitor of power peaks equal to 1350 kwp. Also having a system with agm at 48v 110 amps, even if the house is not manned 24h/24 I arrived at the producer in the hours of the day so from 7 am to 19 pm 4.5 kwh. Thank you all .

 

[DIYrich]

At those time of day, the watts produced are probably not worth the hassle of optimizing. Spend your money on another panel if you need more power.

 

[frankz66]

At those time of day, the watts produced are probably not worth the hassle of optimizing. Spend your money on another panel if you need more power.

Hi and thank you, I don't need more power, I have enough. I was asking if it is a nuisance as you define it, or considering the solar movement and its inclination, it is normal that I have verified these small fluctuations.

 

[Supervstech]

Sounds normal to me.
Good sluthing.

 

[frankz66]

Sounds normal to me.
Good sluthing.

Thank you, right now I have updated the situation of the state of light at 17.30 PM when the sun starts to set and then gets dark at 20:00 PM. As you can see from this image I think it is physiological due to the inclination of the sun that the light now hits the first 4 panels to the west and in the morning the opposite phase for the first 4 to the east. These are 2 strings of 4 panels that descend in parallel . I don't use blocking diodes ..... I don't know if they are necessary ... I am also attaching the state of production today. I remember that I am a beginner and I have been learning for just over a year ... In addition, the system is in a partially manned house during the day.

 

[DIYrich]

Shading is the problem in the picture.
Instead of looking at total production for the day, look at the graphs of production during the day. You will likely see a typical production curve (hump), with production just starting/ending (minimal production) at the times you mentioned.

 

[frankz66]

Shading is the problem in the picture.
Instead of looking at total production for the day, look at the graphs of production during the day. You will likely see a typical production curve (hump), with production just starting/ending (minimal production) at the times you mentioned.
View attachment 213636

The graph was only summary, but the shadow I think is physiology, as written before when the sun rises to the east it is normal because of its angle that hits the first panels that are in the shadow at 17, vice versa for the other four that receive more light around 17 because of the angle. But I ask you, does this involve anomalies to the system or not? Do I need to put blocking diodes if necessary or not? In case it would be appropriate to put them I have 2 MC4 of 25 amps. Thank you .

 

[DIYrich]

The graph was only summary, but the shadow I think is physiology, as written before when the sun rises to the east it is normal because of its angle that hits the first panels that are in the shadow at 17, vice versa for the other four that receive more light around 17 because of the angle. But I ask you, does this involve anomalies to the system or not? Do I need to put blocking diodes if necessary or not? In case it would be appropriate to put them I have 2 MC4 of 25 amps. Thank you .

If the shading is during the day, an optimizer (what you call a blocking diode) may help. If it is at the beginning or end of day, the optimizer won't add much.

 

[frankz66]

If the shading is during the day, an optimizer (what you call a blocking diode) may help. If it is at the beginning or end of day, the optimizer won't add much.

Thanks rich, I know well what an optimizer is, yes the shadow is necessarily in the morning and in the evening respectively on the opposite sides.

 

[DIYrich]

If your panels have bypass diodes, what would be the purpose of the blocking diode?

 

[hwy17]

If the panels are all on the same plane then the sun's angle is identical on all panels at all times. Well, technically it's 99.99999999999999999% close to identical.

The only factor to consider here is the shading. And if you ask me the answer to the question of adding extra diodes to arrays the answer is nearly always no. Diodes introduce forward losses.

 

[frankz66]

If your panels have bypass diodes, what would be the purpose of the blocking dio

If your panels have bypass diodes, what would be the purpose of the blocking diode?

Always taking into account my skills as a beginner, the block diodes (the one in the photo), should be installed between the two strings to prevent one from becoming passive with respect to the other. In my system the strings are separated but they are cointed in parallel, so I always remain doubtful about how and if they should be installed. Be patient but my degree of knowledge at the moment stops here. The system is fine and I'm happy about it.

If the panels are all on the same plane then the sun's angle is identical on all panels at all times. Well, technically it's 99.99999999999999999% close to identical.

The only factor to consider here is the shading. And if you ask me the answer to the question of adding extra diodes to arrays the answer is nearly always no. Diodes introduce forward losses.

The panels are installed as shown in the photo with the same inclination and angle .

 

[DIYrich]

Oh, I get it. String-to-String difference. I wouldn't worry about it. Again, it is during a low production part of the day.