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Romy,

If you didn't have children I'd suggest a new forum topic devoted to solar power quality and Audio.

There are lots of technical papers on solar inverter output quality, especially related to harmonic distortion levels (additive in the case of individual panel microinverters) excessive EMI and square wave forms affecting voltage, and how these problems can limit the amount of solar that can be acceptable in a single distribution system. There are, of course, as many inverter quality levels as there are solar providers. In such a competitive market cost is primary - thus quality is secondary. Solar buyers are not usually aware that such a thing as power quality exists - so they don't take the care you did in looking at inverter specs.

A lot of this is poor filter design. Inverters have more than one frequency to deal with (PWM carrier wave frequency, IGBT switching frequency) - along with EMI. They need carefully designed LC filtering and snubbers to deliver reasonable levels of noise and THD.

I read one ad from one of the better solar inverter suppliers touting their THD levels as "comparable" with some UPS systems - not a promising claim.

We recently installed 3 PurePower 3000's in a solar powered home with in-panel 240 volt micro-inverters with good results and no problems. Our recent experience with our unhappy audiophile is no doubt a resonance problem between a high THD solar installation and our input EMI filter coil - not a component we ever hear from in the normal world. In fact in 14 years of PurePower installations we have never had a case of input filter noise. All past instances of reported coil noise involved output filters and were load dependent.

It is pretty clear that many, if not most, solar installations result in poor power quality that would detract from audio system performance. In my humble opinion there is a simple remedy. A PurePower regenerator will cure the low voltage, high THD and noise while delivering more instantaneous current and better dynamics from the audio system and thanks to recent experience, we can avoid any resonance problems.>>

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