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

[austinpop]

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[The Computer Audiophile]

So cool @austinpop! Thanks so much for writing this up. I very much look forward to the second installment. 

[jcbenten]

Cool writeup.  

Different topic but would be interested in what made the decision to go with Tesla.

Luckily I live in Williamson county (surrounded by Austin/Cedar Park) and will not have to deal with city utilities when we decide to go the solar route.

[fheller]

Very interesting. Thanks a lot @austinpop.

[austinpop]

33 minutes ago, jcbenten said:

Cool writeup.  

Different topic but would be interested in what made the decision to go with Tesla.

 

One word: cost. Tesla was by far the cheapest. The bids from local solar contractors were all at least $10k higher. 

 

33 minutes ago, jcbenten said:

Luckily I live in Williamson county (surrounded by Austin/Cedar Park) and will not have to deal with city utilities when we decide to go the solar route.

 

Howdy neighbor!

[AudioDoctor]

The MN Winters are exactly why I insist on having a wood burning fireplace in my house. Sure it's nice and cozy to sit around in the winter, but the worst case scenario we have heat.

[seeteeyou]

What's next? Maybe streaming Qobuz via FTTH by local ISP versus SpaceX's Starlink?

[The Computer Audiophile]

6 minutes ago, seeteeyou said:

What's next? Maybe streaming Qobuz via FTTH by local ISP versus SpaceX's Starlink?

I have a Starlink article coming :~)

[astrotoy]

I have a similar configuration to austinpop, 36 solar panels (from Solar City now Tesla installed 12 years ago) and three Tesla powerwalls, installed last March.  This summer I bought a Trifield EM100 meter and measured the noise level of my AC line when the powerwalls were providing all the power to the house. The readings were between 18000 and 19999 the maximum number that the meters can record.  Then, at night, when I just using power from the grid, the numbers were around 500, much more typical numbers.   However, I could not hear any effect on my audio system either time.

 

I contacted the designer of my audio power supply - Scott Rust, of 512 Engineering.  I have two of his Symmetrical Power Supply transformer units and have my entire system connected through the two units.  Here is Scott's explanation of why my audio system is unaffected by the high readings.

 

The Trifield description states  “  The Line EMI Meter measures electromagnetic interference in a single-phase AC power line.“.  The symmetrical power supply produces a dual phase output (60 volts one phase and 60v opposite phase).  This means that this particular tool is not capable of understanding and measuring the performance of the symmetrical power supply.    It’s actually measuring only one phase of the power and is not able to “see or appreciate ” the effects of the balanced power signal.  It’s actually quite difficult to measure the performance of the power transformer.    I’ve found the easiest way to measure the power supply performance is actually by measuring the result of sensitive equipment connected to it.      I would expect that a typical single phase  “power conditioner “ would read much lower as advised.  

 

Regarding the Tesla power walls:    I’d expect some pretty heavy duty switching of power at high rates of speed, which would indeed elevate noise on the power line.   The transformers are very good at doing this, I would expect this noise to be greatly reduced at the output of the (Symmertical Power Supply) transformer.    

 

Larry

 

[steve21]

Really interesting, thanks for sharing. Light years away from when we used to wait till after midnight for "clean power" listening sessions. 

[austinpop]

I just heard back from my project advisor at Tesla that they don't have any "publicly available" THD spec for the PowerWall. 

 

However, I did hear from a user on Reddit, who compared his grid and PW output on a 'scope, and made a video. Interesting waveforms!

 

https://www.reddit.com/r/TeslaSolar/comments/qh2m4s/comment/hj01mma/?utm_source=share&utm_medium=web2x&context=3

 

[austinpop]

I just want to re-emphasize that I went into this fully aware — and expecting — sonic degradations any time I was running on the PV panels or on the Powerwall batteries. If the listening tests prove otherwise, I will treat it as an unexpected bonus.

 

That is why the test I described in the article was so crucial. As long as my grid path was not degraded by the install, I could always configure grid power during my listening sessions.

[feelingears]

Fascinating, and informative. Thank you! Apropos of nothing, I personally don't find the idea of 5% or 10% to be meaningful while I can see the conceptual appeal. I think it really actually discourages people from discovering how GREAT that 5% really is.

 

Often, that "5%" is EXACTLY what I am paying $$$ to get because that "x%" is exactly the increase in realism or detail or <fill in your favorite audio attribute> one can hear but that neither words, nor numbers, can realistically do justice to. The resulting emotional engagement is, or is not, greater.

 

Anyway, keep on exploring the margin, austinpop! More 5%! Thanks again.

[vortecjr]

Great article and looking forward to part 2.

[JoeWhip]

Congrats Rajiv on the solar install. I looked into doing the same thing but due to the topography where we live in PA, we would get little to no power using solar in the winter and not enough in the summer to make it worthwhile. Even Tesla told us not to do it. As for Mr. Fremer’s issues with his Generac generator, we installed a 27 kw Generac several years ago running on our natural gas line. Same transfer switch as MF and we have no SQ issues at all. I listen during power outages and notice no degradation in SQ. Again, congrats on the solar install. I would do it in a heartbeat but for the topography issues.

[PeterG]

Great piece!

 

Just so there are no misunderstandings on the economics for people who may be considering solar--In many states, the economics of solar are extraordinarily good.  In Massachusetts, I have a 6 year payback period and I'm earning over 15% annual return (IRR).  My electric bill, which includes powering my Tesla, HVAC (mini splits), and lights, is usually negative after accounting for incentives from the utility.  Financially, it's the best investment available to a "normal" person--about 2X the stock market, with much less risk.  (This does not include battery backup such as Powerwall)

[austinpop]

1 hour ago, PeterG said:

Great piece!

 

Just so there are no misunderstandings on the economics for people who may be considering solar--In many states, the economics of solar are extraordinarily good.  In Massachusetts, I have a 6 year payback period and I'm earning over 15% annual return (IRR).  My electric bill, which includes powering my Tesla, HVAC (mini splits), and lights, is usually negative after accounting for incentives from the utility.  Financially, it's the best investment available to a "normal" person--about 2X the stock market, with much less risk.  (This does not include battery backup such as Powerwall)

 

Hi Peter,

 

Thanks for raising this point. I was focused on describing my ROI situation in Texas. Of course, in many parts of the country, the ROI is much more compelling, from a combination of:

• state and local rebates and credits,
• utility rebates,
• federal tax credits,
• true net metering,
• using batteries for rate arbitrage. with time-of-use rates.

As I said, there is a whole rabbit hole to go down regarding the ROI of solar and batteries!

[Jud]

I’d expect THD slightly worse than the 2% maximum required of most utilities for grid power. I doubt it will make much difference, because the major factor is not external power quality, it’s the noise from internal sources like LEDs, small appliances, the refrigerator, etc. (which is why it’s nice to have a separate circuit for the audio system).  And then of course there are interactions within the system.

 

Congratulations on setting up your solar and battery backup systems. Entirely apart from your audio system, the increased peace of mind will be invaluable.

 

Our house has a solar photovoltaic system and is prewired for backup batteries on the garage wall when we choose to do that. The house was built “green,” so we needed an installation of less than 4kw capacity to provide 100% of our usage (net metering basis). There’s plenty of room for more (Pueblo style house, flat roof with low parapet that shields panels from street view), so we’ll likely add more when we do batteries.

[PYP]

Great article.  And nice, clean install!   Looking forward to your future findings. 

 

I don't have a battery backup, so I can only observe sound during the day, when the solar is cranking away, and once the sun has set.  No difference.  I was concerned about the solar monitoring device that runs to my router via the electrical system (the available wifi option is apparently unreliable).  Tested it plugged/unplugged.  No difference.  Not sure if the dedicated lines to my setup are the reason.  

 

Regarding ROI, I think it was 7+ years to break even in my location.  I enjoy listening for most of the day, yet the most recent month of electricity bill was negative (don't have an electric car yet).   Will continue to follow the cost of battery backup.  When I received a recent quote, my response was:  Now I know why Elon Musk is the richest guy on the planet.  

[austinpop]

38 minutes ago, Jud said:

I’d expect THD slightly worse than the 2% maximum required of most utilities for grid power. I doubt it will make much difference, because the major factor is not external power quality, it’s the noise from internal sources like LEDs, small appliances, the refrigerator, etc. (which is why it’s nice to have a separate circuit for the audio system).  And then of course there are interactions within the system.

 

Congratulations on setting up your solar and battery backup systems. Entirely apart from your audio system, the increased peace of mind will be invaluable.

 

Our house has a solar photovoltaic system and is prewired for backup batteries on the garage wall when we choose to do that. The house was built “green,” so we needed an installation of less than 4kw capacity to provide 100% of our usage (net metering basis). There’s plenty of room for more (Pueblo style house, flat roof with low parapet that shields panels from street view), so we’ll likely add more when we do batteries.

 

Wow, if 4kW meets your usage in New Mexico, you must have a really efficient home. Well done!

 

One of my pending experiments is to chase down what seems like a 1.1kW "ambient" draw in my house. Not sure what accounts for that, but I need to wait until all the civilians in the house are safely away before doing a breaker by breaker analysis. Data is fun!

[vortecjr]

17 minutes ago, austinpop said:

 

One of my pending experiments is to chase down what seems like a 1.1kW "ambient" draw in my house. Not sure what accounts for that, but I need to wait until all the civilians in the house are safely away before doing a breaker by breaker analysis. Data is fun!

Maybe the system is using it?

[Jud]

33 minutes ago, austinpop said:

 

Wow, if 4kW meets your usage in New Mexico, you must have a really efficient home. Well done!

 

Congratulations go to our contractor, former head of the New Mexico Green Builders Association. We talked to a family he built a home for before we decided to go with him, and they said “He’ll listen, so he’ll do it the wrong way if you insist, but first he’ll explain to you why he wants to do it the right way.” 🙂

 

33 minutes ago, austinpop said:

 

One of my pending experiments is to chase down what seems like a 1.1kW "ambient" draw in my house. Not sure what accounts for that, but I need to wait until all the civilians in the house are safely away before doing a breaker by breaker analysis. Data is fun!

https://sense.com/thisissense?utm_source=google&utm_medium=&utm_campaign=Non-Brand-SmartShopping&utm_term=&utm_content=&gclid=EAIaIQobChMIwou_hYX78wIVcm5vBB2mkgfOEAQYAyABEgJNO_D_BwE

[PeterG]

15 hours ago, Jud said:

The house was built “green,” so we needed an installation of less than 4kw capacity to provide 100% of our usage (net metering basis).

4kW or 40kW?  If 4, please share (lots) more details.  Thanks!

[beetlemania]

I have a 2300W grid-tied system, installed 2011 before prices of panels really dropped. I made sure to buy US-built PV panels but the microinverters were made in China. Six inverters failed within the first year and the manufacturer paid to replace all. 
 

My city has its own power utility. I don’t understand why Public utilities are not the norm. The city has hydro, natural gas, and PV generation, buys the rest on the market including about 10% portfolio in wind. The first, I think, 400 kWh are billed at about $0.10 per kWh and the price is tiered upward with increasing usage. Between the low rates and my relatively expensive system, I figure about 20 years to break even. But that’s not why I did it.

 

Never once thought about how the system might affect the sonics of my audio system. Maybe grid-tied changes nothing but I didn’t notice any change back in 2011. My wife was concerned about sleeping under the panels above our bedroom but I pointed out the power leaves with the sun.

 

The Tesla batteries seem cool but I hold Musk in the same regard as Bezos. Just not gonna give those dudes my money.

[beetlemania]

My 2300W system provides about one-half of my annual usage (I’m in northern Utah which gets tons of summer sun but lots of clouds during winter). I can easily imagine an efficient house in NM, with relatively even solar radiation throughout the year, getting by with a 4 kW system.