Solar charged battery system providing electricity for audio system

[RickyV]

34 minutes ago, Nsxturbo said:

Hey Ricky,

 

Yeah the earthing rods with the special soil mix, the whole nine yards. I really should buy a decent scope just to get a visual of what’s really going on.

 

So about a week ago I heard this out of the ordinary sound coming down the street and could hear the turbo whine, it was the KTM, my neighbor just got one! It’s frigg’n wicked! You must have a blast!

 

Whoops slightly OT, some are a bit sensitive about that, but I think you have a KTM x-box in mind. On my two wheeled version it’s a blast too.

 

Anyway, is there any particular reason you choose the yeti, other then the pure sine wave? Why not more in home kind of system and a bank of deep cycle batteries. Sorry my enthusiasm is running wild.

 

darn it my food is burning 

[Nsxturbo]

I chose the Yeti for its simplicity and the audio review of the smaller version. However, subsequently to purchasing it, I found a rack mounted one and some others with a more detailed listing of their specs and and ripple, but I was also concerned about their fan noise. The thing I liked about the rack mounted one is that it didn’t switch over to the batteries until that AC line was interrupted. That way, it could keep equipment running off the AC until you wanted to switch over, eliminating the warm up time some of the audio equipment needs to sound their best.

Right now, I keep the Yeti AC output running some of my electronics full time for that warm up issue, so I keep an AC to DC charger on it to keep it at full charge. 

I will have to dig up the info on the rack mounted one, and I’ll post that here once I do.

[One and a half]

5 hours ago, thotdoc said:

This thread is so typical: We start with my question re battery driven audio and the need for filtration and we are at the stage of people trying to prove they are right about "epidemiologic data support an association between surrogate measurements of magnetic fields and an increased risk of childhood leukemia". 

This occurs over and over on most threads here.

 

Is it possible for people on this site to stay focused and answer the original question? I know it's possible some places because I race a Porsche in SCCA and the threads associated with Porsche racing issues on the SCCA site and the Pelican Parts site stay on track....bada-boom! On those sites the members are very direct if you are off topic.

 

Is there any desire to stay on topic? Can we self govern?

 

BTW I've found the answer: Because of noise generated within the inverter process along with assorted antennae effects, and the fact that one may want to use the system outside the time that the battery prevails, one needs to something to clean that noise.

 

Now, the question becomes what is the best noise reducer...but there is a thread for that.

You will find that using an isolation transformer on the output of an inverter will greatly reduce common mode noise. 

Dont expect miracles from inverters as even the good ones don’t provide better than 2% THD. 

Earthing systems are critical and need to completely compliant with wiring rules where you live for safety as well as noise reduction.

[RickyV]

6 minutes ago, One and a half said:

You will find that using an isolation transformer on the output of an inverter will greatly reduce common mode noise. 

Dont expect miracles from inverters as even the good ones don’t provide better than 2% THD. 

Earthing systems are critical and need to completely compliant with wiring rules where you live for safety as well as noise reduction.

 

But is the 2% THD better or worse  then what the mains does. Well it depends on the area of  cause.

[Nsxturbo]

I must admit, I have not tried running an isolation transformer after the sine-wave inverter but I have a .00005pf capacitance one I can try for reference and post that result here. It 

[One and a half]

1 hour ago, RickyV said:

 

But is the 2% THD better or worse  then what the mains does. Well it depends on the area of  cause.

2% is about as good as it gets for homes these days on the grid. Caused by a multitude of smps, and solar inverters of varied quality feeding into the grid. 

 

The distortion is caused by a multitude of harmonics and their strengths. For the perfectionist, make your own with a rotary generator synchronous motor setup with DC excitation from batteries. 

 

For the rest of us a filter trapping the 5th harmonic is an optimum way of reducing THD, but it’s a) messy to measure, b) dissipates heat c) moderate cost d) selected large enough for your house but not the neighborhood.

 

Just live with the distortion, like paying tax, avoidable with a price.

[sandyk]

6 hours ago, Ralf11 said:

Speaking of motor vehicles...  I bet you could find a pretty nice 12 V DC amp in a Lexus, MB Maytag, or a Rolls.  IIRC, Lexus uses a JBL system that is custom designed for them.

 

 

 Please enlighten me as to how you can obtain any more than a few watts of power into a 12V car's typical 4 ohm speakers without the use of converters typically using MosFets for switching, to step up the voltages to more typical of those used in a home system.

[Ralf11]

Please enlighten me as to how you could make the assumptions required to ask a question like that.

[Speedskater]

A lot of the popular, newer solar panel systems in the US are known sources of noise and interference.

[barrows]

The performance of the inverter is critical here, and these vary a lot.  one needs a true sine wave inverter, and hopefully one with very low distortion.  There are Plenty of bad inverters out there.  You would want a true sine with distortion at full output of (hopefully) less than three percent.  One might also be able to add a powerful regenerator to correct fro the effects of a less than perfect inverter, but one would want to consult with the regenerator manufacturer to be sure it will not be adversely effected by the output of the inverter.

[Jud]

I did research on this before my home was built in 2017.  You may be surprised to learn that at least as of 2nd or 3rd quarter 2017, there were no inverters on the market that had power quality specs (for example, harmonic distortion and power factor) better than US utility power, and perhaps one or two I could find that even had equivalent specs.

 

Regulations on utilities in the US are fairly strict about power quality.  Contrary to popular imagination, most power quality problems are inside the home (appliance motors, digital controls that are in everything from toasters to lighting now) rather than out.  So unless something has changed drastically in the past 2 years or less, you'd actually start out with better power quality from the grid.  Therefore, yes, you'll want to clean up power from your home inverter, whether it's a regenerator, isolation transformer, something else, or a combination.

[austinpop]

On 7/31/2019 at 7:33 AM, RickyV said:

 

I mean something like a ps audio, DirectStream Power Plant 12 but with a dc "battery" input. 

I have no idea how the sine wave looks or the noise on a normal inverter is.

 

I had the same thought... could PS Audio produce audiophile inverters using just the inverter stage of their regenerator products. I don't know what DC voltages these home solar/battery systems use, and how it compares to the internal DC used in the Power Plants.

[Nsxturbo]

Hey Jud, thank you for your insightful post. I am now running my low capacitance Topaz transformer after my sine wave inverter. There is definitely not some dramatic chance in the sound quality, but I’m sure it is not worse and probably would measure better.

I wanted to clarify that while I am listening to my off the grid system, it is running strictly on DC battery power with no solar or other charging devices connected.

 

And I did want to reiterate, that I have a extremely thoroughly implemented dedicated AC system coming directly from my homes outside service entry not from my existing inside main breaker panel. And truly there is no comparison, the DC derived sine wave inverted AC absolutely crushes that dedicated grid AC!

 

So the question is: could there be other reasons besides line ripple that contribute to that drastic improvement of the DC derived system?

[RickyV]

10 minutes ago, Nsxturbo said:

Hey Jud, thank you for your insightful post. I am now running my low capacitance Topaz transformer after my sine wave inverter. There is definitely not some dramatic chance in the sound quality, but I’m sure it is not worse and probably would measure better.

I wanted to clarify that while I am listening to my off the grid system, it is running strictly on DC battery power with no solar or other charging devices connected.

 

And I did want to reiterate, that I have a extremely thoroughly implemented dedicated AC system coming directly from my homes outside service entry not from my existing inside main breaker panel. And truly there is no comparison, the DC derived sine wave inverted AC absolutely crushes that dedicated grid AC!

 

So the question is: could there be other reasons besides line ripple that contribute to that drastic improvement of the DC derived system?

 

Could it be that the ac near you is heavily polluted?

[Nsxturbo]

Absolutely! without testing it as I said in my original post, my grid AC could be atrocious. That is why I would hesitate to apply my local results broadly to everyone else. 

I really need to a decent scope for tangible measurements for any of my experience to be translatable to other’s AC setups.

[Jud]

4 hours ago, Nsxturbo said:

Absolutely! without testing it as I said in my original post, my grid AC could be atrocious. That is why I would hesitate to apply my local results broadly to everyone else. 

I really need to a decent scope for tangible measurements for any of my experience to be translatable to other’s AC setups.

If you’re in the US (and very likely other developed countries), by law your grid power cannot be “atrocious.” It actually has to conform to extremely tight specifications, tighter than all but a very few inverters, and at least equal to the best available inverters (as of mid to later 2017, anyway). This isn’t some general average specification, it’s a minimum requirement.

 

So I’d look elsewhere. Perhaps due to no need for transformers or ac/dc conversion internally. Or perhaps the power actually measures worse but sounds better to you. Impossible to know, and in any case I’m certainly no expert.

[RickyV]

16 hours ago, austinpop said:

 

I had the same thought... could PS Audio produce audiophile inverters using just the inverter stage of their regenerator products. I don't know what DC voltages these home solar/battery systems use, and how it compares to the internal DC used in the Power Plants.

 

I have asked Paul, just for fun. I think it’s a good idea, “the green audiophile” benefiting the environment, SQ and maybe cheaper to build. We’ll see if I get an answer. 

[Ralf11]

Jud - do you have a cite to the law on that?

 

Also, I suspect it is measured at the source or a sub-station.  Possibly, a noise source could be down the block from your house (or in an adjoining apt.) and mess up your AC line, yet remain undetected at the measurement point (assuming there actually are measurements, and not just a technology based estimate the way air pollution sources are treated).

 

I suspect the conclusion is correct however - noise (if it exists and affects your SQ at all) is likely coming from inside your own house.

[Jud]

18 hours ago, Ralf11 said:

Jud - do you have a cite to the law on that?

 

Also, I suspect it is measured at the source or a sub-station.  Possibly, a noise source could be down the block from your house (or in an adjoining apt.) and mess up your AC line, yet remain undetected at the measurement point (assuming there actually are measurements, and not just a technology based estimate the way air pollution sources are treated).

 

I suspect the conclusion is correct however - noise (if it exists and affects your SQ at all) is likely coming from inside your own house.

 

The ANSI standard measures at two points, the service entrance to the home and the point of utilization (individual appliances, lights, etc., within the home).

 

The laws (regulations) are done by individual state Public Utility Commissions or equivalent bodies.

[Ralf11]

Thx - the PUC has not measured anything at my house.  I think we have a specification that is not tested.  Maybe it doesn't need to be tested, but I don't know.

 

I do think it would be interesting, if not useful, to run a system (or at least the DAC) off of pure DC, and that we will see more of that in the future.

[AudioDoctor]

I have a feeling that a solar charged battery, perhaps with some wind to help as well, will be the future as we move to a more sustainable form of energy. It has the added benefit of decentralizing the power grid too, making it more secure.

[Jud]

7 hours ago, Ralf11 said:

I do think it would be interesting, if not useful, to run a system (or at least the DAC) off of pure DC, and that we will see more of that in the future.

 

Jeff Rowland Design used to make a DC amp, don't know if they still do. @Nsxturbo, I imagine you may be the homegrown expert here.   

 

[Jud]

6 minutes ago, AudioDoctor said:

I have a feeling that a solar charged battery, perhaps with some wind to help as well, will be the future as we move to a more sustainable form of energy. It has the added benefit of decentralizing the power grid too, making it more secure.

 

Yep.  Have solar that has supplied slightly over 100% of our power needs since we've been here (relatively small system - pretty efficient home), and the system is wired to be able to hook up batteries conveniently along an interior garage wall.  Looking forward to getting those in a couple of years.

[AudioDoctor]

I’m very interested in an off grid house using solar and wind as power sources alongside a gas (propane) tank and good old wood burning fireplaces. 

[Jud]

11 minutes ago, AudioDoctor said:

I’m very interested in an off grid house using solar and wind as power sources alongside a gas (propane) tank and good old wood burning fireplaces. 

 

The wood burning fireplace is (a) a romantic idea, and (b) something I personally love to see.  But it also (a) requires cleaning vs. a gas fireplace (Jotul makes very nice gas fireplaces - they have furnace-rated blower systems that can keep a floor of your home from freezing if the rest of the heating system goes on the fritz), and (b) is energy-inefficient enough that I think I remember you can have trouble getting something like a LEED certification if you have one.

 

We have propane for in-floor radiant heat and hot water (one small - probably 2' x 2' x 10" or less  - tankless boiler supplies both), electricity for the rest. Use less than 400 gallons of propane a year (maybe $30/month averaged out), but then our winters are nothing like MN.  Got down to about 12F for the low one day this winter (we're at 5700 feet), and that's as cold as it's been in 2 years.