Article: The Audio Impact of Solar Panels and Battery Backup: Introduction, Installation & Initial Listen

[One and a half]

36 minutes ago, MrDerrick said:

I will follow this closely.

 

Three of my neighbors who have solar city installs share the same transformer secondary with me.

My THD as measured by my PS Audio power plant has gotten quite bad.

 

I do not live in the sun belt, 17403 zip, and poor sunlight affects output which appears to have a direct influence on how clean the inverters operate.

Strong sunlight = low THD, low sunlight = high THD.

 

I can hear the effects on my audio system, power supply noise and loss of SQ.

Late nights are the only time that I can thoroughly enjoy listening in the summer.

Thank god winter is coming.

Thank you for this interesting observation. To achieve low THD, the inverter a) has to be capable of producing better than 2% THD, and b) have a low impedance source or strong enough to cope with large di/dt when the switching devices work.

 

If the sunlight is poor, the internal resistance of the solar cells decrease the source impedance as seen by the inverter. If the source impedance is higher, there's less energy , or quality energy that the inverter needs.

 

One way around this is to add more capacitance to the DC bus network for the inverter, however the solar cell array may not have enough strength to support the capacitance. Difficult issue. Not a great fan of inverters or UPS for audio equipment, trading voltage stability for grid strengths and noise closeness certainly has a fine line between pros and cons.

[One and a half]

8 hours ago, Jud said:

 

When I was looking 4 1/2 years ago, I found no inverters capable of better than 2% THD, and only a handful capable of equaling that.  Is there anything with better specs now?  (2% THD or better is what most electrical utilities must meet in the US by regulation.)

A vintage brand ELGAR is still produced under that name a house of Ametek. Their SW series can create DC as well as up to 2kHz at line voltages (120, 230V) at 0.25% distortion into a linear load, like a heater. As soon as there's a rectifier anywhere, that distortion increases.

I'm sure Ametek have a DC input inverter in another family, but any programmable power that is used to calibrate other instruments are at $5figures, unfortunately. 

2% for reactive loads is about the best that's available without resorting to specialised filters to improve the distortion.

Elgar-SW.pdf