Is Solar power dirty?

[Jeroen3]

Would putting several tens of microfarads directly across the output of a solar inverter help reduce any high frequency noise going out into the AC line?

You only put capacitors on the grid to compensate for inductivity.

If you are experiencing harmonics issues after installation this can be because the part of the grid you are on has a "high impedance". This could mean the transformer you're on is small, or the lines are long. You can't do anything about this except lowering inverter output, storing energy in batteries, or even installing your own transformer or line reactor. Or just take more load.

[SeanB]

Typical thing to reduce noise is to put in filtering, generally the power companies have LC filters across the phases, and also have harmonic traps in series with the phases, typically tuned to the third harmonic so that the current is more likely to approach a sine wave. The distribution transformers though tend also to be part of the filtering, simply because they are also inductors in the path, though some utilities also deliberately include a bypass capacitor across primary and secondary of the transformers ( tuned to resonate at a predetermined frequency) to pass through the power line control signalling used to control things like power switching, line taps and street lighting, without having to run any extra communications cabling.

[DougSpindler]

Even if solar inverters produce "dirty" power, don't consumers back-feed dirty power with the devices they connect to it?  Such as motors?