Power factor - impact of solar self-consumption

The integration of solar production can have a negative impact on the overall power factor

The integration of solar production can have a negative impact on the overall power factor (PF) of the electrical installation and may lead to penalties if corrective measures are not taken.

In fact, because the solar system is producing and providing active energy only, less active energy is required from the grid for the same amount of reactive energy. Thus, the power factor at the point of grid connection is reduced accordingly.

To learn more about the impact of solar integration on power factor and see a practical example, watch “How to avoid power factor penalties due to photovoltaic production.”

How to avoid power factor degradation due to the integration of solar production?

There is an easy way to avoid power factor penalties when integrating solar production which does not require installing additional power factor correction equipment.

By regulating the inverter’s set point, the solar inverters can provide not only active but also some reactive power. Therefore, controlling the inverters' set point to choose the right balance of active/reactive power they inject in the electrical installation, makes it possible to improve the global power factor of the electrical installation to the expected value.

To see a practical example, watch “How to avoid power factor penalties due to photovoltaic production.”

Fig. P48 – Example of electrical installation

• 

  without solar production

• 

  with solar production providing active power only (by default)

• 

  with solar system with an appropriate set point value of the solar inverters to avoid power factor penalties

The power factor regulation through solar inverters can be implemented with power measurements at the photovoltaic installation and at the connection point to the grid, together with a control system that calculates and communicates the appropriate set point to the inverters.

Fig. P49 – Power factor correction through an appropriate set point value of the solar inverters

This method is very well adapted in terms of compensating power factor degradation generated by the PV system itself, and with high accuracy.

However, it is not efficient to compensate the power factor degradation due to the loads, for 2 reasons:

• firstly, because solar production is only available during the day,
• and secondly, because the inverters are limited in the reactive energy they can provide.