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Re: Solar Power

Posted: Tue Jan 24, 2012 12:33 pm
by RaTTuS
http://www.amazon.co.uk/Powere.....00681LZ68/

now would that power an RPi?

Re: Solar Power

Posted: Tue Jan 24, 2012 1:02 pm
by hyuecn
I'm thinking of trying with http://www.solartechnology.co.uk/

I hoping it might be possible to take one of these apart and use the panel sections to make a case for the pi

Re: Solar Power

Posted: Tue Jan 24, 2012 1:42 pm
by n3tw0rk5
I suppose it depends on how long you want the RasPi to run off the battery pack that the panel will be charging.

Then it will need a bit of maths to figure out the drain on the battery and the size panel needed to recharge it in a reasonable abount of time.

I've got plenty of solar related bit's n pieces in the garage so will be having a play once i get me hands on a RasPI.

Re: Solar Power

Posted: Tue Jan 24, 2012 1:56 pm
by MINKIN2
Lifehacker made a video sometime ago, where they used the solar panels from those cheap garden lamps to charge a mobile phone.

I can't find the video ATM, but it was simple enough. Take 6 garden lamps and remove the Solar panels, solder the corresponding connections to each other with two left for the phone plug. Attach the plug and hey presto, He's ALIVE!!!!

They placed it in the sleeve of a photo album for portability too

Sorry I can't provide the link. Would be ideal for the pi

Re: Solar Power

Posted: Tue Jan 24, 2012 2:15 pm
by rurwin
In response to the OP, the panel appears to generate 100mA so, in bright direct sunlight and ignoring charging efficiency, it will power the RPi for one seventh of the time you left it in the sun. More like two thirds that because of the charging efficiency, and much much less if it isn't in direct sunlight. Light is logarithmic; if you think it's a little dull, there's probably only about 5% sunlight reaching you. Hazy sunlight, window glass or indirect sunlight will significantly increase charging time, cloud cover will increase it by ten times or more, and artificial light would be worthless.

Which does not mean that it is unreasonable, but you should probably plan on using a larger panel, like of the order of square feet.

Re: Solar Power

Posted: Tue Jan 24, 2012 2:30 pm
by S0litaire
This looks like what you were talking about:

http://hacknmod.com/video/how-.....charger-2/

Using 4 panels from garden lights to charge a phone.

Re: Solar Power

Posted: Tue Jan 24, 2012 3:09 pm
by hyuecn
How about steam power?

Re: Solar Power

Posted: Tue Jan 24, 2012 3:16 pm
by n3tw0rk5
hyuecn said:


How about steam power?



Think my little mamod steam engine would need to be a tad bigger.

Re: Solar Power

Posted: Tue Jan 24, 2012 3:25 pm
by hyuecn
n3tw0rk5 said:


hyuecn said:


How about steam power?


Think my little mamod steam engine would need to be a tad bigger.


It would be an awesome project though, a coal-powered pi

I'd love to try, if I had the know how, just as a technical exercise

Maybe use a piston to drive a dynamo

Re: Solar Power

Posted: Tue Jan 24, 2012 4:03 pm
by RaTTuS
rurwin said:


In response to the OP, the panel appears to generate 100mA so, in bright direct sunlight and ignoring charging efficiency, it will power the RPi for one seventh of the time you left it in the sun. ....


Excellent thanks that is the sort of info I need ...

right off to find another solution...

Re: Solar Power

Posted: Tue Jan 24, 2012 4:07 pm
by hsoftdev17
http://www.amazon.com/Brunton-.....038;sr=8-4

These are expensive, but have a much better shot at running a RPi.  They claim a max of 800mA at 5v so you may be starving the RPi in less than ideal sun conditions, but at least you have hope with this.  :)

Hope it helps.

Re: Solar Power

Posted: Tue Jan 24, 2012 4:21 pm
by Joules
Ideal solar supply for Rasberry and a few peripherals.

https://powertraveller.com/iwantsome/pr ... eyextreme/

Not cheap, but quite robust.

Re: Solar Power

Posted: Tue Jan 24, 2012 4:22 pm
by Rubus
hyuecn said:


n3tw0rk5 said:


hyuecn said:


How about steam power?


Think my little mamod steam engine would need to be a tad bigger.


It would be an awesome project though, a coal-powered pi

I'd love to try, if I had the know how, just as a technical exercise

Maybe use a piston to drive a dynamo


To charge a battery to power the R-Pi.

If you were powering the R-Pi directly from the dynamo you'd have to have extra coals on hand in case you clicked on a link to a website that had lots of Flash.

Re: Solar Power

Posted: Tue Jan 24, 2012 4:47 pm
by rurwin
hsoftdev17 said:


http://www.amazon.com/Brunton-.....038;sr=8-4

These are expensive, but have a much better shot at running a RPi.  They claim a max of 800mA at 5v so you may be starving the RPi in less than ideal sun conditions, but at least you have hope with this.  :)

Hope it helps.



That's a proper solar supply, and it is 1.5 square feet of panel. Compare that with the two hand-held chargers that have been posted. I assume that the solar angle on those chargers is a gimmick -- there is no way they can charge fast enough to make sense -- they are batteries that you usually charge from the mains, but can just about charge themselves in a few days of good sunlight.

Re: Solar Power

Posted: Tue Jan 24, 2012 4:49 pm
by crundy
S0litaire said:


This looks like what you were talking about:

http://hacknmod.com/video/how-.....charger-2/

Using 4 panels from garden lights to charge a phone.



Quick warning: That site seems to have been infected with one of the fake antimalware / new browser scareware apps. Don't visit it!

Re: Solar Power

Posted: Tue Jan 24, 2012 5:01 pm
by hyuecn
I have a freeloader and actually it works pretty well, when travelling it was often the only way to get my mobile to charge. However you are right to suggest that it works best by being charged up first by the sun, and then using the stored power rather than charging as you go.

It would be good to see whether the pi could be solar powered; I think there must be an real world application for a low budget solar pc. I remember at school building a lego greenhouse and using a thermometer with a simple programme to make the windows open upon reaching certain temperatures. Maybe in LEDCs a solar pi could be used to manage an irrigation system or similar.

I reckon there is enough know-how on this forum to make that happen, and in some ways is the point of it (wow, that sounded preachy!)

Re: Solar Power

Posted: Tue Jan 24, 2012 5:55 pm
by error404
hyuecn said:


I have a freeloader and actually it works pretty well, when travelling it was often the only way to get my mobile to charge. However you are right to suggest that it works best by being charged up first by the sun, and then using the stored power rather than charging as you go.


Solar systems are usually designed this way; their output is really inconsistent throughout the day, so you're either getting very poor utilization of your solar energy collection, or you're only able to use your device for a couple hours a day (on a clear day).


It would be good to see whether the pi could be solar powered; I think there must be an real world application for a low budget solar pc. I remember at school building a lego greenhouse and using a thermometer with a simple programme to make the windows open upon reaching certain temperatures. Maybe in LEDCs a solar pi could be used to manage an irrigation system or similar.


This sort of control application is better suited to a small microcontroller that can actually run (easily) on a small solar panel like this. No need for a 700MHz ARM and 256MB of RAM just to open a vent and start a fan!

That said, those little solar charger thingies do work reasonably well for something like a mobile phone that can run off its own battery for a day or two while the solar gizmo accumulates charge. I have one and it's gotten me through a couple week-long camping trips well enough - but the power consumption of an idle cell phone is quite low. Powering the Pi you really need to decide what the duty cycle is going to be first, then design your solar solution around that. If you want to make good use of it each day though I suspect you'll want something larger, like a 5W panel. You're also going to want some kind of battery & associated charger. 12V SLA is the easiest and most available, but also large and heavy.

Re: Solar Power

Posted: Tue Jan 24, 2012 6:09 pm
by mgmt_idiot
For those of us planning to live in Idaho with 5 years' supplies

http://biolitestove.com/CampStove.html

Re: Solar Power

Posted: Tue Jan 24, 2012 7:53 pm
by n3tw0rk5
mgmt_idiot said:


For those of us planning to live in Idaho with 5 years' supplies

http://biolitestove.com/CampStove.html



Thats damn nifty!

Re: Solar Power

Posted: Tue Jan 24, 2012 8:38 pm
by Themroc
hsoftdev17 said:


http://www.amazon.com/Brunton-.....038;sr=8-4

These are expensive, but have a much better shot at running a RPi.  They claim a max of 800mA at 5v so you may be starving the RPi in less than ideal sun conditions, but at least you have hope with this.  :)

Hope it helps.


Eeek! Right, thats extremely pricey! I'd suggest something like this http://www.amazon.com/Instapar.....038;sr=8-2 + that: http://www.amazon.com/Motorola.....38;sr=1-11

Needs some soldering, though...

Re: Solar Power

Posted: Tue Jan 24, 2012 10:45 pm
by orbitoid
Assuming that the Pi will be under 100% load the whole time, how many Ah would you need to power it for say 24 hours? (worse case)

If we could work that out then we could look for batteries that would suit. Then we could also work out what kind of wattage the solar panels would need to keep the battery afloat.

Would Lithium batteries be the best for this type of job?

I suppose working out how many hours of actual useful sunlight in a day would be a good thing too.

I've been looking at trying to build a wind turbine to help along side a solar panel to make my (soon to be) Pi a 24hour 7 day computing micromachine!

Re: Solar Power

Posted: Tue Jan 24, 2012 11:07 pm
by stormy1
Orbitoid said:


Assuming that the Pi will be under 100% load the whole time, how many Ah would you need to power it for say 24 hours? (worse case)


700ma + usb load

use 1 amp to make it easy. (it has a 1amp fuse)

so 5v 24AH

Re: Solar Power

Posted: Tue Jan 24, 2012 11:47 pm
by Mezo
There is the F&P smartdrive (washing machine motor) option, puts out about 300w of electrickery, theres also some good info on solar on this site also.

http://www.thebackshed.com/Win.....ents.asp#2

Great site with all sorts of hacks.

Mezo.

Orbitoid said:

I've been looking at trying to build a wind turbine to help along side a solar panel to make my (soon to be) Pi a 24hour 7 day computing micromachine!

Re: Solar Power

Posted: Wed Jan 25, 2012 12:38 am
by n3tw0rk5
Well my RasPi will be solar powered from the start, allthough it isnt what you would call a portable setup.

I've got 2 x 50 watt panels on the garage roof that feed into a 20a charge controller, connected to that I have a 12v 110ah ups battery that i blagged from a datacenter I used to work at and a 400w inverter for 240v stuff.

At the moment this runs my cable modem, wifi router and garage lighting, so i think it should handle a RasPi cluster as well (almost forgot it's used to run a pump when i'm doing a batch of home brew)

But I will be seriously looking at what I can put together to make a portable option, allthough my idea is more of maybe using a tablet battery and a small pv panel as more of a ups so the RasPi can be moved between more permanent power sources without having to power it down.

Re: Solar Power

Posted: Wed Jan 25, 2012 1:57 am
by Codyak
Themroc said:


hsoftdev17 said:


http://www.amazon.com/Brunton-.....038;sr=8-4

These are expensive, but have a much better shot at running a RPi.  They claim a max of 800mA at 5v so you may be starving the RPi in less than ideal sun conditions, but at least you have hope with this.  :)

Hope it helps.


Eeek! Right, thats extremely pricey! I'd suggest something like this http://www.amazon.com/Instapar.....038;sr=8-2 + that: http://www.amazon.com/Motorola.....38;sr=1-11

Needs some soldering, though...


Any idea if you could wire two of these together somehow to help boost the amps?