Power factor impact on grid-tie inverters

[Jordi]

Dear all,

Here a noobie trying to understand the effects of power factor on a grid-tie inverter.

I am about to receive a grid-tie inverter from Aliexpress that I will connect to a 100W solar panel and there are 2 claims in the product specifications:
1) Efficiency = 86% approx.
Which I assume is the conversion efficiency from DC to AC (apparent power).
2) Power factor = >98%.
Which I believe is the percentage of produced AC (apparent power) that can produce work at the destiny load (real power).

Link inverter: https://www.aliexpress.com/item/32918257215.html?spm=a2g0o.cart.0.0.2e523c00XFgg1Y&mp=1

I assume therefore that when using this inverter at home I will produce 0,86 x 0,98 = 0,84 (84%) real power and almost 2% reactive power from the DC feed (panel or battery).
Since my production is quite low compared to what my house consumes I expect that all reactive power (the 2%) will be consumed on-site.

BUT, If that was not the case, what would happen to the reactive power? Would it be sent to the grid? Would I be financially compensated for that?

I read that households pay for apparent power and therefore my logic says I should be also compensated for reactive power not consumed or even the excess sent to the grid under the concept of apparent power. Is that correct?

I also have another question regarding the quality of the inverter based on product reviews. Say that the power factor is much lower than advertised (eg. 74% instead of 98%). Is that a reason to open a dispute on Aliexpress? What kind of compensation should I ask? I do not fully understand the consequences of a lower power factor when dumping electricity to the net. I do understand that for an off-grid inverter a low power factor would mean not being able to run certain devices due to insufficient real power while apparent is enough.

Could the power factor of the inverter be related to my connection to the grid? Like a factor differing per building, province, country,...

Please I very much appreciate plain answers, this reactive power thing is still quite abstract to me.

 

[time2roll]

At 98% the inverter is power factor corrected and for the intended use the power factor is a non issue.
If by some miracle there is actual power sent back to the grid, the compensation is based on kWh regardless of power factor.

 

[Jordi]

At 98% the inverter is power factor corrected and for the intended use the power factor is a non issue.
If by some miracle there is actual power sent back to the grid, the compensation is based on kWh regardless of power factor.

Thank you time2roll , By kWh you refer to apparent power, right?

When the fridge motor stops my house only takes 5W, so eventually I may be sending something to the net. Shortly, could you please name a couple situations where the power factor could cause a limitation/problem? Learning.

 

[time2roll]

By kWh I mean actual power pushed back into the grid. Power factor describes how efficient the produced power can be utilized by the load. So I believe the inverter will match 98% with the utility sine wave and push 98% into the grid when the house loads are zero. Usually power factor is described as the utilization efficiency of the load to use the entire curve of the sine wave. Some items like a microwave primarily use power from the peaks and have a lower power factor or utilization of the available power. This requires more available power than what is utilized. The full available power is the apparent power. This is part of the reason modified sine wave does not work well on some items.... the curve is distorted and there is a lower peak voltage. Motors and microwaves can run poorly or run hot on modified sine wave.

Xantrex white paper on power factor