Excellent sustainable move Steve, sounds like hopefully both economically and environmentally good return on investment. To get the sustainability trifecta ensuring no downsides with SROI (social return on investment) would be the go. That is making sure your music (social value) is as good or hopefully better than ever.
I do remember reading a thread on an audio board some years ago where potential impacts of the inverters in PV (ie solar) systems was discussed in some depth.
From memory a group of the guys that used to listen to each other’s systems regularly (a bit like the Boston guys here) noticed in one session that the system they were all familiar with that often really delivered the music and magic just didn’t do it at all sudden.
After some head scratching the lights went on for the guy who owned the setup (stressful moment I’d imagine having your mates around and then your pride and joy goes cactus on you) and so he went out of the room and when he came back a few minutes later put the tunes back on and voila the system was delivering the music as magic again. Apparently he had just installed a solar hot water system and so he wondered if that was the issue so he went out and without saying what he was doing just switched off the inverter.
So the guys tried the experiment a few more times on and off with the solar inverter and it was decided to be the culprit. Zero clue if this was double blind test but they probably were drinking anyway so some level of cloud over the science here and if then this is just another bit of audiophile folklore that took hold ie inverters are bad for the audio setup.
From memory as the discussion progressed a few salient points came to light. The first of which was that the quality and kind of noise generated varies quite a bit between different quality inverters and that cheaper hot water systems tended to utilise cheaper inverters with possibly greater attendant THD and RFI noise being fed back into the system.
So here assuming the kind of the level of research that Steve would do plus his drive towards doing it always in the best way that his PV system would also be highest grade and that the inverter would likely be of similarly high spec.
Just floating another possibility for some of the variances in experience with an inverter making noise an in audio system might also potentially be the way the system itself is set up.
When I had the Anima horns here for a few months I found the various system tweaks that I found so critical with the 20.7 Maggies just didn’t seem as obviously necessary for the horns. Lesser cables, lesser electrical and mechanical isolation was needed to get what the horns could deliver than was necessary for the ribbons.
I have put this down to the difference in perceptual experiences created and their specific ingredients. In short, the ribbon panels do sonics really well and then require sources that do music naturally and convincingly to then deliver sound and music and so rely on a different mix of resolutions than did the Anima horns setup with 300B amps and preamp used and where the focus on resolution was essentially/fundamentally different. With the few horns I tried then the key feature for me was the uninterrupted experience of the flow of the music as the ultimate and essential ingredient of the horn SET experience.
However I’d imagine the kind of highly shielded cable solutions that your setup runs Steve might obviate the kinds of potential noises that an inverter might add especially the kind of PV setup you have with likely a better engineered inverter.
DDK’s setup has never been as reliant on tweaks and highly engineered ancillaries beyond the core components (the source with the amps) to make it’s magic so the cables are simpler and likely less shielded so these might just be more vulnerable to a significant noise issue that an inverter in the circuit might bring and so his very different experience with the outcome of trialling an inverter.
One other point made in the thread by one of the posters was that the quality that they noticed when comparing with and without inverter switched on was that it wasn’t so much an overtly noticeable sonic issue but rather a loss of connection to flow in the experience which is more a holistic appreciation and someone even commented that a system that trades in its capacity to portray natural flow (like perhaps a horn SET system) might be most vulnerable to this as the flow is one of their most essential qualities.
All anecdotal, all subjective, so just floating these as potentials for discussion rather than suggesting any of these are the answers though. My next setup of horns and SET will be added here shortly but I’ll be going instant gas water heater over solar hot water just in case.