Raspberry Pi powered by solar module

peterw

New Member
I want to run my Raspberry Pi with Wifi dongle powered by solar panels.

Do you know a everything included package that can be bought and sold in the EU?

How big should the solar panels be to have enough power for a Raspberry Pi?
 

drmike

100% Tier-1 Gogent
Which Pi model are you using?  Dictates solar needs to some degree.  Need to figure out power draw on the dongle too.. 

24/7 operation?  Guess of typical sunny hours of sun without shade, obstructions?   How many cloudy days there a year?

I'll estimate it for you.
 

peterw

New Member
Raspberry PI FAQ:


Typically, the model B uses between 700-1000mA depending on what peripherals are connected.
The maximum power the Raspberry Pi can use is 1 Amp.
If you need to connect a USB device that will take the power requirements of the Raspberry Pi
above 1 Amp then you must connect it to an externally powered USB hub.

The power requirements of the Raspberry Pi increase as you make use of the various interfaces
on the Raspberry Pi. The GPIO pins can draw 50mA safely (that is 50mA distributed across all the pins!
An individual GPIO pin can only safely draw 16mA),
the HDMI port uses 50mA,
the camera module requires 250mA, and k
eyboards and mice can take as little as 100mA or over 1000mA!
Check the power rating of the devices you plan to connect to the pi and purchase a power supply accordingly.

1A * 5V = 5W needed.

Even more for the 12V to 5V step down and to charge the battery for night.

Solar panels work with 12V so I need 12V batteries and a charging regulator.
 

drmike

100% Tier-1 Gogent
This is a guy who did the same project.  B model Pi. 45 Harbor Freight solar kit (Chinese tool importer in the US).   

45 watt 3 panel kit, commando style mounted and shaded in bad way with already sub par panels....

80AH 12V battery, assumed to be a retail deep cycle model used in boats, RVs and other pleasure crafts.

Doesn't seem clear how he down stepped the 12V power, but, HF kits do have USB power output for one of the ports on the power controller with the kits (controllers are pretty poor quality).

Site appears to be served from the solar Pi which is ultra cool :)

http://pi.qcontinuum.com/project.html
 

drmike

100% Tier-1 Gogent
There are ample 12V to 5V converters out there, including bundling the USB.  Ebay has a few different Chinese made models.  Loss is negligible and rather simple task (every lighter plug  outputting USB does the same and those can be found for little cost).

5W is if you aren't powering your dongle otherwise.....  

5 x 24 = 120W = 10A @ 12V   call it oh 12A....

Most places are capable of getting 4 hours of sun on panel face if mounted "optimally".  So you need 4 hours @ 3A...  just to cover the 24 hour period.  3A = 36 watts of 12V panels... But there are losses all over... so  you need a bit more...  In fact you also need to bank power for cloud days to coast and later get that battery charged....

So if I needed 36 watts, I'd get a 60 watt panel.

That's still not tons of head room if you are in a chronically cloudy, dark local.
 

Damian

New Member
Verified Provider
So what do you guys have in place for overnight power?

Nevermind. Reading is a mystery to me....
 
Last edited by a moderator:

bizzard

Active Member
We had run Pi on solar power, with storage batteries of course, along with a DC powered LED monitor, USB HDD and USB CD drive. It was a port of the Freedom Toaster, to raspberry Pi to burn CD/DVD's for an event. 

I was more involved in porting the code, but could hook you up with the guy who did the solar module part. There were minor issues of over heating of the solar charger, but I believe it has been fixed by now.
 

Neo

Member
In a other forum we said: at least 80AH, at least 130Watt (for the winter), that is enought to power the PI 8 days in a row without the sun.
 
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