What's that diode in a solar panel for?

Click For Summary
SUMMARY

The discussion focuses on the function of diodes in solar panels, specifically addressing their necessity in configurations with multiple panels versus single panels. A diode, as illustrated in diagram A, is essential when multiple panels are used, particularly if one panel is shaded, as it allows current to continue flowing. In contrast, the diode in diagram B is only relevant if there is a risk of reverse current from the powered device, which is particularly important at night when batteries could drain through the panels. For single panels, the diode is not required unless reverse current is a concern.

PREREQUISITES
  • Understanding of solar panel configurations
  • Knowledge of current flow in electrical circuits
  • Familiarity with the concept of blocking diodes
  • Basic principles of photovoltaic systems
NEXT STEPS
  • Research the role of blocking diodes in solar energy systems
  • Learn about the effects of shading on solar panel performance
  • Explore the differences between series and parallel solar panel configurations
  • Investigate the impact of battery voltage on solar panel operation at night
USEFUL FOR

Solar energy enthusiasts, electrical engineers, and anyone involved in the installation or maintenance of solar panel systems will benefit from this discussion.

John1397
Messages
189
Reaction score
18
Solar panels come with a diode like in diagram A what does this accomplish as I always hook them up like in diagram B
 

Attachments

  • panel.PNG
    panel.PNG
    3.1 KB · Views: 552
Engineering news on Phys.org
The diode in diagram A is useful when you have multiple panels and one is covered by clouds. This allows current to keep flowing in that case. For a single panel it is not required. It doesn't hurt to be there except for extremely small panels when working in the micro-amp range.

The diode in diagram B is only useful if there is a chance that the powered device may produce a current. You don't really want to feed current through you solar panel. If that condition is not possible it is best to leave it out.

BoB
 
  • Like
Likes   Reactions: engnrshyckh
rbelli1 said:
The diode in diagram B is only useful if there is a chance that the powered device may produce a current. You don't really want to feed current through you solar panel. If that condition is not possible it is best to leave it out.

This condition exists at night when the batteries connected to the solar panels have a voltage that can cause the panels to drain the battery through the panels. So unless you disconnect your battery at night you need a "blocking diode".in series with the panel.
 
gleem said:
So unless you disconnect your battery at night

Or have no battery.

BoB
 
rbelli1 said:
The diode in diagram A is useful when you have multiple panels and one is covered by clouds.
And in that case, the ground symbol goes away, and the diagram shows multiple panels.
 
  • Like
Likes   Reactions: rbelli1

Similar threads

Solar panel conundrum -- Not enough power?
  • · Replies 7 ·
Replies
7
Views
2K
Reverse-Flow Protection Mosfet Control?
  • · Replies 10 ·
Replies
10
Views
2K
Solar panel with circuit inside a PC box -Not working
  • · Replies 3 ·
Replies
3
Views
2K
Do personal PV panels make sense considering the grid "cleanliness"?
  • · Replies 14 ·
Replies
14
Views
2K
Is it possible to run a pond filter using a solar panel?
  • · Replies 13 ·
Replies
13
Views
4K
How do copper oxide solar cells work?
  • · Replies 2 ·
Replies
2
Views
2K
Switching between parallel and series connections (solar)
  • · Replies 31 ·
2
Replies
31
Views
5K
Could you use Solar to power a DC to AC Inverter? (Description below)
  • · Replies 6 ·
Replies
6
Views
4K
Net metering - hybrid solar inverter system question
  • · Replies 9 ·
Replies
9
Views
1K
With two DC charging sources, are blocking diodes required?
  • · Replies 6 ·
Replies
6
Views
3K