Indeed next DG inverters will be able to command not only active power but also reactive power. However, this cannot be generalized. We should see the application we are talking about. What is clear is that for low voltage ride through features it is necessary to command reactive power both positive and negative sequences, regarding three phase or single phase faults.

In my opinion, we should define firstly the function of inverter. If we want the inverter works to inject active power only, so inverter must work at near of unity PF. If we want the inverter works to compensate reactive power, the inverter can work at non-unity PF.

Indeed next DG inverters will be able to command not only active power but also reactive power. However, this cannot be generalized. We should see the application we are talking about. What is clear is that for low voltage ride through features it is necessary to command reactive power both positive and negative sequences, regarding three phase or single phase faults.

Depends on what the generator is paid for. If it's paid for active and reactive power it can generate both otherwise it's waste of money. For instance, in micro FIT (Feed-In-Tariff) the small generators are paid for active power only so what's the point to generate both? You would waste the resources (and invested money) to generate something you are not paid for. Therefore in micro FIT the generators work at the unity power factor. Not sure about FIT though.

I guess the previous answers are right. It makes more sense to generate active power from DG.

I might add though; the statement in the question is right, if it was talking about the power factor contributed by harmonics/distortion. It is necessary that DG inverter produces very low harmonics content, i.e. near unity power factor.

Hi to all

While discussing about the DG , we should also consider the fluctuations they would add into the sources when connected to a grid

So in my opinion the inverter depends upon the DG technology, that either active power or reactive power is to be supplied

In Germany inverters of PV systems have to be able to fee in reactive power. This feed in can reduce the voltage raise in a distribution grid. If the voltage raises to much an harm the upper 10% border of the nominal voltage (standard EN 50160) the grid operater have to reinforce his grid to avoid this.

The PF factory could be varible from around 0.85 to 1.