Does Solar PV affect the Power Factor?

Case Study: Solar PV vs.Power Factor

Location:  A Manufacturing Facility

The origin of this article began when a factory received information suggesting that the newly installed solar PV system might have an impact on the power factor. This raised concerns among the stakeholders, leading the factory to also seek greater visibility into the performance of the solar system itself. In this case, Truewatts stepped in to support both the factory and the investor/EPC by analyzing the data to provide clearer insights into these concerns.

While many experts have previously discussed the topic of solar PV and its impact on power factor, this article aims to offer an additional perspective, helping readers better understand the situation through actual measurement data.

To understand the theoretical reason why a solar PV system can affect the power factor, it’s helpful to first understand the concept of the Power Triangle. This link provides a clear and detailed explanation of the concept.

In cases where a solar PV system is installed, the active power (P) typically decreases, while the reactive power (Q) remains unchanged. This alters the geometry of the power triangle, which in turn leads to a reduction in the power factor.

At this particular site, a PQube3 Power Quality Meter (PQM) had already been installed. This meter can simultaneously monitor two three-phase systems. During the system commissioning phase, the factory and EPC agreed to measure at two points:

1. the Main (recommended by the utility), and

2. the Solar connection point.This dual monitoring setup allowed both the investor/EPC and the factory to clearly see the system’s overall behavior.

The graph below clearly shows how the energy reduction at the Main point aligns with the operation of the solar system. Additionally, it can be seen that the power factor at the Main also correlates with the time periods when the solar system is active.

For any facility that has a Power Quality Monitoring system installed alongside its solar PV system, it’s highly recommended to download and analyze the data. As often said, you may discover “hidden insights” within the information. In some cases, you might find opportunities to improve even further—beyond the savings already achieved from solar—whether by enhancing efficiency or identifying underlying issues early on.

For facilities using PQube3, simply open the daily report email automatically sent by the device. No matter where you are in the world, you can easily access the data without traveling to the site—saving time, travel costs, and potentially preventing operational losses that might otherwise go unnoticed.

Lastly, the author personally believes that installing a solar system remains one of the most effective solutions for significantly reducing electricity costs.

(If the graphs presented in this article did not fully cover the discussed points, I sincerely apologize in advance.)

E: info@truewatts.co.th

W: www.truewatts.co.th