Solar Powered Hifi

[Figlet108]

Since having my attic converted to an office and setting up a hifi up there; and since it's very fashionable these days to experiment with mains regenerators, balanced mains etc etc all in a bid to provide the best juice to the system, my thoughts turn to a solar powered hifi experiment.

After all, on other more highly evolved planets everything is powered by the Sun - isn't that what the Sun's role in the universe is?

Anyway, surely it can't be that hard (or expensive) to do a DIY solar power solution for a hifi.
Here's an all-in-one package for a 580W system for less than £700:
http://www.bimblesolar.com/12v-290w-complete
2x 290W panels
1x 30A charge controller
1x 110Ah batteries
cable + connectors

I'll also need an inverter, but here's the beauty of the plan - I already have one of those in the form of a Power Inspired AG1500, which is already designed to take power from batteries.

I haven't figured out all the details or fully designed the system, but was curious if anyone else out there had done something like this?

[Ali Tait]

It may well be designed to take power from batteries, but I'm not sure how good it would sound doing so. Inverters usually give a pretty horrible waveform.

[synsei]

Nope, but I like the sound of it, as may you once it is installed ;)

[Stubies]

I think the trick would be to stay in dc - don't use an inverter- maybe use a T class amp, that will keep your power consumption down and smiles up :)

[Ali Tait]

Yep, or remove the mains transformers from your kit and power them directly. No big Class A amps though!

[Figlet108]

It may well be designed to take power from batteries, but I'm not sure how good it would sound doing so. Inverters usually give a pretty horrible waveform.

Ali, now I'm confused. I thought the AG1500 first converted the incoming AC to DC, and then converted that DC to 'perfect' AC.
With Solar am I not just bypassing the first AC->DC conversion?
Isn't the AG1500 supposed to be an inverter that gives a very good ('perfect') waveform?

What am I missing?

[Ali Tait]

Maybe nothing! :lol:

I don't know how the PI works, never had one. If it operates as you say, should be no problem to do as you propose.

[Stubies]

Jason

I'm pretty certain all electronics convert the ac to dc before it is used. thus why go back to ac then to dc? The perfect wave form you mention really just helps to achieve a clean dc current inside the component. And you already have a clean dc source - a battery.

I'm not sure what is the typical dc voltage used in an amp or CD player (other AoS members can say for sure). But some are definitely 12 v like T amps. Thus if you chose components with the same internal dc voltage as your storage battery (perhaps 12 v - perhaps there is more than one option).

In any case if you use an inverter (or half an AG1500) then u will loose substantial energy in the transition back to ac, then back to dc inside each of the components. Not sure exactly how much but I guess it would cut your play time by at least half.

Can anyone offer insight on the typical internal dc voltage in components?



Ali, now I'm confused. I thought the AG1500 first converted the incoming AC to DC, and then converted that DC to 'perfect' AC.
With Solar am I not just bypassing the first AC->DC conversion?
Isn't the AG1500 supposed to be an inverter that gives a very good ('perfect') waveform?

What am I missing?

[Ali Tait]

Jason (Stubies), you are correct with what you are saying, but the point here is to get the cleanest power possible, for the best sound. Not sure myself if there will be much or any improvement, though I guess it will be cheaper in the long run, once the cost of all the kit has been paid for by the leccy generated!

Typical DC is indeed 12v from the secondary of the mains trannie inside a piece of kit. This may be reduced further to feed regulators for things like dac chips etc. Different in valve stuff of course, which can operate at hundreds or even thousands of volts DC.

[walpurgis]

I can't see any difficulty in assembling a small but decent solar powered system. As Stuart suggests a (DC input) Class T amp would be a candidate. Reasonable sized solar panels are easy to source and a sealed lead acid battery or two should do the job, just make sure the voltages are workable and use high sensitivity speakers. I have a 12v solar powered CCTV system that works in much the same way (only the recorder is mains).

[Ali Tait]

Aye, should be no problem as you say. Whether it will sound any better is the question..

[Figlet108]

Stuart,
yes I agree 100% with all your points and using the DC directly would be stage 2 of the process. The only advantage of initially using the inverter (AG1500) is purely convenience and speed of getting something working.
As Ali says 12v will serve most sources and would certainly power my PC and the DAC.
I'm not sure about the EAR 509s and the QUAD ESLs that will also need power but I'm guessing they will want more than 12v and I don't fancy screwing around with the PSUs for those right now as it's just a distraction from the Solar side of things which I want to focus on for now.

Ali,
agreed it may not make any difference, but it will be fun and educational to find out :)
It would be interesting to compare the impedance from a Solar DC-direct supply compared to a regenerated AC supply.

[Ali Tait]

Aye, will indeed be interesting, and I'd like to know how you get on. Not sure how good the dc will be from the panels direct, I'd use them to charge a couple of batteries or more, and feed the system from them perhaps.

[Figlet108]

I can't see any difficulty in assembling a small but decent solar powered system. As Stuart suggests a (DC input) Class T amp would be a candidate. Reasonable sized solar panels are easy to source and a sealed lead acid battery or two should do the job, just make sure the voltages are workable and use high sensitivity speakers. I have a 12v solar powered CCTV system that works in much the same way (only the recorder is mains).

Thing is Geoff this project is only worth doing for me if I get to power my system unmodified (PC->DAC->EAR 509s->Quad ESL 2805)
So if like Scotty, I don't have the power Captain, I'll just buy more panels...

[Figlet108]

Aye, will indeed be interesting, and I'd like to know how you get on. Not sure how good the dc will be from the panels direct, I'd use them to charge a couple of batteries or more, and feed the system from them perhaps.

Yes absolutely. I have no plans to power directly from the panels as apart from anything else I'll probably want to listen in the evening from the power generated earlier on in the day.
Either way, stage 1 will be to go via batteries and the AG1500.

[Ali Tait]

Thing is Geoff this project is only worth doing for me if I get to power my system unmodified (PC->DAC->EAR 509s->Quad ESL 2805)
So if like Scotty, I don't have the power Captain, I'll just buy more panels...

For your valve amp, the problem will be supplying the high DC voltages required. You could just run it from the PI, but you'll need a big bank of batteries to get any reasonable listening time.

[Figlet108]

Yep, that's the bit that concerns me the most.

If it turns out to be too impractical I'll take the 509s downstairs and use a class A/B SS amp with the Quads instead which I know will want 35v-40v

I think the next stage is to do some homework to calculate how much power I'll need for decent listening times, not to mention minor details like where and how to fix the panels to the roof...

[synsei]

Perhaps you could incorporate a charging system from the mains to cut in when the batteries are getting low. Perhaps this isn't entirely within the spirit of what you are attempting to achieve but at least this way you have guaranteed power during those late night listening sessions and you would still save a good bit of money over keeping it all mains powered ;)

[wee tee cee]

i run quad 63s with temple audio mono blocks no problem driving them using a passive tisbury audio pre.......just set the appropriate impedance levels on the amps via the power button......lovely combo!!!!! and i do believe they can be powered by a 12v battery but a check with John audio at temple would confirm this!

just a thought....also lets you run very short speaker lengths (i velcro the amps onto the statics)....

[daytona600]

decent inverters are not cheap , Avoid anything that is not pure sine wave , good for lights but shocking for Audio
12/24vdc solar inverters like steca from germany are excellent
decent solar batteries are shockingly expensive , car/automotive or leisure/caravan if drained ( deep discharge ) will last days

why not fit a system to your roof to power the whole house - " you never get a bill from the sun "
you can add batteries if you want to go - Off Grid

http://www.suntrol-portal.com/

[Stubies]

Ah, i see you already knew that :)

At the risk of being boring (again!) - there is another advantage to going direct dc - it would probably cut your investment in 1/2, since you would only need 1/2 the batteries and 1/2 the solar cells to charge them to get the same playing-time.

Still - im keen to see your progress, as would many of us. Please share your cost figures and post some pictures. One day this type of project will be low-enough-cost to tempt me too!



Stuart,
yes I agree 100% with all your points and using the DC directly would be stage 2 of the process. The only advantage of initially using the inverter (AG1500) is purely convenience and speed of getting something working.
As Ali says 12v will serve most sources and would certainly power my PC and the DAC.
I'm not sure about the EAR 509s and the QUAD ESLs that will also need power but I'm guessing they will want more than 12v and I don't fancy screwing around with the PSUs for those right now as it's just a distraction from the Solar side of things which I want to focus on for now.

Ali,
agreed it may not make any difference, but it will be fun and educational to find out :)
It would be interesting to compare the impedance from a Solar DC-direct supply compared to a regenerated AC supply.

[Sovereign]

I was waiting for you to pitch up Daytona, didn't you say it was a great improvement when you went solar?

[walpurgis]

Thing is Geoff this project is only worth doing for me if I get to power my system unmodified (PC->DAC->EAR 509s->Quad ESL 2805)
So if like Scotty, I don't have the power Captain, I'll just buy more panels...

I don't know the power requirements for the 509's, but I'd imagine a couple of roof-fulls of solar panels may just cope (but only when it's very sunny). And of course you'd need a handful of lorry batteries. :)

[Figlet108]

Perhaps you could incorporate a charging system from the mains to cut in when the batteries are getting low. Perhaps this isn't entirely within the spirit of what you are attempting to achieve but at least this way you have guaranteed power during those late night listening sessions and you would still save a good bit of money over keeping it all mains powered ;)

Dave, that's not a bad idea and certainly I need to ensure the show must always go on and never run out of juice.
The only problem is deep cycle lead acid batteries that are the ideal choice for this last longest and best when you don't let the charge ever get below say about 50% (exact specs will vary). So whatever I do I need to architect the system to ensure I never run out of juice or go below 50%.

[Figlet108]

i run quad 63s with temple audio mono blocks no problem driving them using a passive tisbury audio pre.......just set the appropriate impedance levels on the amps via the power button......lovely combo!!!!! and i do believe they can be powered by a 12v battery but a check with John audio at temple would confirm this!

just a thought....also lets you run very short speaker lengths (i velcro the amps onto the statics)....

Hey Tony, yes those temple audio mono blocks do look good and from the website: "It still works great with Sealed lead acid batteries, or any high quality power supply between 9V and 18V DC", so defo an option.
However, I'm pretty determined to make the system work with my preferred kit and damn the laws of physics :)

[Figlet108]

decent inverters are not cheap , Avoid anything that is not pure sine wave , good for lights but shocking for Audio
12/24vdc solar inverters like steca from germany are excellent
decent solar batteries are shockingly expensive , car/automotive or leisure/caravan if drained ( deep discharge ) will last days

why not fit a system to your roof to power the whole house - " you never get a bill from the sun "
you can add batteries if you want to go - Off Grid

http://www.suntrol-portal.com/

Hey Scott, yep I'm just starting to peel the layers of the onion away on this and seeing how expensive the decent kit is.
Purpose made pure-sine inverters for the solar industry seem to be £1000+. I quite like the look of this one: Outback Inverter (http://www.outbackpower.com/index.php/outback-products/inverters-chargers/item/vented-vfx2612e?category_id=447)
But it's £1.5k, which is why at least initially I'd like to try and use my Power Inspired AG1500 inverter.

So, onto batteries - wow they are really expensive!
The best (and pretty much only option for keeping them inside the house) are Absorbed Glass Mat (AGM) sealed lead batteries.
For a top 12v 1000aH battery you are looking at about £900
For me batteries are a must. I'm only likely to want to use the system in the evening.

The final component that's needed is a charge controller. Prices vary from £50 to £600.
The state of the art seems to be something like this one, again from Outback. (http://www.outbackpower.com/index.php/outback-products/charge-controllers/item/flexmax-80?category_id=438)
This is the only one I've seen that handles 60v batteries, which would be a must if I was going to use the Solar DC directly to my kit (looking at you here Stubies)

So to answer the final question as to powering the whole house with Solar, well that's just what I'm considered now I've looked into it... but with a twist.
It turns out that the panels are the least of the expense! A good 240W panel is £120. The max I can get on my SE facing roof is x11 = £1320 = 2540W

Thing is, I originally and naively thought I could just slap on a couple of panels myself, get a cheap car battery and connect it to my existing inverter and do the whole thing for a few hundred quid. Reality is somewhat different. No way is a 20kg panel measuring 1600x1000 going to be installed 6m up without the aid of scaffolding and another pair of hands (e.g. a roofer)
If I'm going to pay for scaff and a roofer I may as well max out the roof with the 11 panels. If I do that my AG1500 wouldn't cope with all that power generated so I'd have to buy a dedicated inverter and all the other kit. To cut a long story short it'll all add up to £5k.
If I did do it, I would create 2 arrays, one for the house and a separate one just for the hifis so that I *could* go direct DC if I so chose (again, quick nod to Stubies)

I've worked out I need 5,500 KWH per year (from last 12 months usage). Are those 11 panels going to be enough? It's hard to tell. If not I could add another 11 panels to the NW facing roof at a later stage.

Another interesting point to consider. Current panels are only about 15%-18% efficient. 18% panels cost £400+. The cutting edge is panels with 45% efficiency. These are expensive, in short supply, and only for satellites and spacestations... How long will it take to get consumer panels to 45%? I'm guessing 10 years.

Anyway, no firm decision made yet. As Ash famously said, I'm still collating data...

[Ali Tait]

Jason,

Go onto audio Talk and have a word with Paul Barker. He installs these kinds of systems and knows all the ins and outs.

[Figlet108]

I don't know the power requirements for the 509's, but I'd imagine a couple of roof-fulls of solar panels may just cope (but only when it's very sunny). And of course you'd need a handful of lorry batteries. :)

509s are 100W each; Quad 2805s are 6W each; PC+DAC will only be a few W
So in total let's say 250W all in.

That's only 2x240W panels at 50% efficiency.

[Figlet108]

Good shout Ali, thanks! It would be good to talk to a non-salesman that knows the industry.

[Ali Tait]

Nae bother.

[Oldpinkman]

Apologies for not reading all of the thread, but I am on metered slow internet atm. Reminds me of a fabulous moment in the dordogne. First time I had taken Mrs S there, took her to Domme. If you don't know it - lovely medieval village on a hill looks over an ox-bow bend in the river. And special magic, in the courtyard overlooking the view was live medieval music from a German playing his own compositions on a hammered dulcimer. We got chatting and bought the CD from him - recorded using solar power, wrapped in paper, tied with twine. He was touring Europe in a horse drawn caravan, making low-carbon music.

Just thought I'd share and hope it's not hopelessly irrelevant to the thread :)

[Figlet108]

Thanks for sharing Richard, and actually not as random as it might appear. The Solar supplier I seem to have homed in on (http://www.bimbleinn.com/) online are a bunch of hippies that rent out mobile solar powered music/event venues and have branched out into Solar kit supply as a side line.

http://www.bimbleinn.com/images/photo_inn_outside1.jpg

[Figlet108]

So still as unresolved as ever on this.

I'm wondering how many panels an installer can do in 1 day? Can they do 11 and max out the roof?
How much does scaffolding cost?
Will a 2.5KW system be enough to cover my 5,500 KWh / year?
Is a 1000Ah battery enough? Too much?
Are more efficient panels just round the corner?

[Ali Tait]

Speak to Paul!

[Figlet108]

Speak to Paul!

I already tried to send a PM to Paul but it won't go through as he's too new.

[Ali Tait]

Go through Audio Talk. Knowing Paul, he won't find much to interest him here.

[NRG]

Will a 2.5KW system be enough to cover my 5,500 KWh / year?

No, not even close and thats assuming a perfect but non-tracked south facing roof mounted 30 deg elevation. You wont even get half of what you need.

[Sovereign]

Scaff will be about £500.
We just re roofed a 4 storey block of flats and the scaff required to get the roofers on the roof was about £650, but that was was obviously considerably higher than a domestic dwelling.