Off Grid Solar Question

[Silgalias]

Hi there. I have a question a about power signals. Would an off grid solar system provide cleaner or noisier power than from the grid?
I would of thought cleaner as it's a closed system. But what about the inverter?

 

[staticV3]

It literally does not matter with modern AC-powered electronics: https://www.audiosciencereview.com/...ac-distortion-noise-on-audio-equipment.25501/

Your inverter could be outputting the dirtiest, nastiest AC sine wave you can imagine and your audio hardware would not care.

 

[Silgalias]

Thank you. Excellent article.

 

[Owl]

We have all seen the stair stepped sine wave depiction of music that the Hi-res audiophile world has advertised. This depiction is incorrect with music, but that is exactly what a, DC to AC invertor sine wave looks like. I lived off grid for many years and used a couple of different in invertors, as with any product, some are better than others. The only concern I had was that the invertor buzzing was carried to the end component. If you placed your ear next to the power supply transformer, be it TV, fluorescent light fixtures, audio amplifier, you could hear the same frequency buzz that the invertor was producing. I don't think it effected audio quality, but it was a concern of mine with appliance longevity.

 

[RayDunzl]

We have all seen the stair stepped sine wave depiction of music that the Hi-res audiophile world has advertised. This depiction is incorrect with music, but that is exactly what a, DC to AC invertor sine wave looks like. I lived off grid for many years and used a couple of different in invertors, as with any product, some are better than others. The only concern I had was that the invertor buzzing was carried to the end component. If you placed your ear next to the power supply transformer, be it TV, fluorescent light fixtures, audio amplifier, you could hear the same frequency buzz that the invertor was producing. I don't think it effected audio quality, but it was a concern of mine with appliance longevity.

Couldn't you send the AC through a big choke to smooooooth it out a little?

 

[mhardy6647]

Heck, I've thought, more than once, about pullin' B+ right off the panels for a vacuum tube amplifier!





Yeah -- I guess it wouldn't work great at night. Need batteries.

In (some) seriousness -- I have never looked at the AC produced by our inverters*, but my guess is that it's pretty clean. Low THD.

I mean, @amirm could test inverters, you know? We'll get him some thick rubber gloves and rubber-soled safety boots.[/URL]

I do know that our Honda inverter generator produces good quality AC (and its pricetag reflects that 'assurance').
______________

* Ours - so far - is configured as a net metering system. I.e., we make juice for our own real time use, and the excess goes back to the grid, spinning the meter backwards (so to speak). We've got about 6kW of PVs on the roof currently. Our daughter & son-in-law recently had a tracker installed to augment their PV system, and now I'm gettin' the urge to put on in, too. We have a relatively unobtrusive site in our west field that has good 'access' to clear sky and wouldn't much impact our "viewshed" nor anyone else's.

EDIT:
A partial view of the field to the west of the house.

 

[mhardy6647]

Couldn't you send the AC through a big choke to smooooooth it out a little?

BIG choke

 

[JeffS7444]

My knowledge on such matters is pretty out of date, so I did a quick survey of current product offerings, and in the case of the Conext XW Pro, think that using it with A/V equipment would be a non-issue, with it's rated <5% THD output spec. In the old days (pre-Y2K), "true sine wave" output was a premium feature, but judging by how hard it Is to find info about inverter output in 2023, and how common grid-tied systems are, would expect "utility-grade" output to be pretty much the standard for house-sized inverters.

You might still find modified sine wave inverters, particularly from older units, or inexpensive, portable ones. And even those would work fine on devices using SMPS for power. Linear power supplies might buzz a bit, and AC synchronous motors may run slow.

 

[DVDdoug]

An inverter is similar to a class-D amplifier so it's possible for the output to be clean.

 

[JeffS7444]

Heck, I've thought, more than once, about pullin' B+ right off the panels for a vacuum tube amplifier!

You're gonna get strange looks at Home Depot when you ask for circuit breakers rated for 600 volts - DC

 

[Philbo King]

A lot depends on your solar set up.
The usual case in grid-tied systems is to have micro-inverters, one on each panel, so the output of each panel is 220VAC, at (or a bit above) 1 amp. These are paralleled into a PV power bus fed into the service panel (i.e., breaker box). There are a lot of advantages to this arrangement:
- In series-connected panels, shade falling on any one panel throttles the current from the entire array. Separate microinverters don't suffer from this issue.
- The summed voltages from a series array can reach or exceed 1000V, requiring special and expensive wiring down to the single inverter. That level of voltage is fatal at the briefest of human contact (that is not to say that touching a 220VAC power bus is safe to touch; it's just a little less likely to cause instant death).

This is why microinverter setups are far more common. If your setup uses a microinverter on each panel, it is not possible to get high voltage DC direct from your panel array. But it's quite easy to connect a DC power supply to it by simply plugging it into the nearest wall outlet.

 

[egellings]

It literally does not matter with modern AC-powered electronics: https://www.audiosciencereview.com/...ac-distortion-noise-on-audio-equipment.25501/

Your inverter could be outputting the dirtiest, nastiest AC sine wave you can imagine and your audio hardware would not care.

Only problem I ca see with an inverter is that if it's poorly designed and spraying RF that could get into audio electronics and degrade the performance of the equipment. Absent that, I see no problem with inverter usage for audio.