ajmas
Posts: 39
Joined: Sat Mar 24, 2012 2:28 pm

Re: Solar powered httpd server

Sat Mar 24, 2012 2:41 pm

I currently have a computer serving up web pages from my home computer, but realistically for the traffic it gets it is consuming far too much power. This is where the Raspberry Pi would come in:

I imagine having a board powered by solar power (and batteries), running an small web server (httpd), also capable of running php. This would be connected to the local network either via wi-fi or fixed ethernet. This would act as the primary server and would wake the main server (via WoL), only for certain sections of the site or if the load reaches a certain threshold.

In fact, I really think a solar powered kit (pre-built or easy to assemble) would be a really useful accessory to the Rasberry Pi.

The setup could probably be made to switch to a mains supply if the battery is below a certain charge and a mains current is detected.

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nick.mccloud
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Re: Solar powered httpd server

Sat Mar 24, 2012 3:04 pm

This is my ambition too.

I'm not sure about the load sharing - I suspect the Pi would be able to handle a fair bit of casual traffic before it got swamped. The bit I'm playing with at present is loading all the SQLite files in to memory from the (SDCard) storage and writing them back out again on shutdown - don't really want to slow things up by running out to SD every time there's a query.

john_wage
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Contact: Website

Re: Solar powered httpd server

Sat Mar 24, 2012 3:05 pm

Since your solution seem to be aimed at cutting down on the electricity bill, I can tell you right now it will be a very hard numbers game.

Switching over to a plain RPi with the standard power source will solve your problem already, because is already a relatively power efficient platform.

You should need to run the solar-powered server for like 10 years before you have saved in the cost for the panel, controller board, and battery.

ajmas
Posts: 39
Joined: Sat Mar 24, 2012 2:28 pm

Re: Solar powered httpd server

Sat Mar 24, 2012 3:21 pm

Using the standard power source is probably a more realistic solution and may end up being the route I will go down.

The solar-powered element is really more of a "nice to have" and a challenge to see what could be achieved and seeing to what extent the device could be made to be independent of the grid, which could be useful experience for other projects, where depending on the grid is not an option.

hzrnbgy
Posts: 106
Joined: Mon Dec 26, 2011 10:55 pm

Re: Solar powered httpd server

Sat Mar 24, 2012 3:21 pm

I concur. Cost saved from using solar power is almost non-existent compared to the initial investment (unless you want to run your RPi for ten decades just to capture the initial investment).

Maybe at certain scenarios where there is no readily available power source (like in the middle of the jungle), solar power might prove itself useful in powering up your ultra power efficient web server. But then again, you might have other issues such as your Internet connection if you do plan on running your web site in the middle of the jungle.

ajmas
Posts: 39
Joined: Sat Mar 24, 2012 2:28 pm

Re: Solar powered httpd server

Sat Mar 24, 2012 4:03 pm

Either way I am going to watch and see what micro-USB based power solutions come onto the market or hobbyists come up with. If anything it would give me an appreciation on how the technology is evolving.

Without the solar panels there is the following battery pack:

http://www.amazon.com/Tekkeon-....._title_def

john_wage
Posts: 156
Joined: Thu Mar 22, 2012 6:20 am
Contact: Website

Re: Solar powered httpd server

Sat Mar 24, 2012 4:16 pm

the whole "micro USB" concept is just to make the device easily usable for beginners right out the box.

You can solder off the micro USB mini-B port and power the device from pretty much any source that can provide 5 Voltages 0.7 Ampere direct current.

Know that 0.7 Ampere or the 700mA is only a recommendation, the device will only need this current under the heaviest load (worst case scenario),

however, would you ever run the RPi on maximum load and your power supply comes short of the 700mA capacity, you system will almost certainly crash.

poing
Posts: 1131
Joined: Thu Mar 08, 2012 3:32 pm

Re: Solar powered httpd server

Sat Mar 24, 2012 4:21 pm

Besides I read there's a part on the board (regulator or something I think) that wastes 40% of the energy to bring the voltage down. If you change that part with a more costly one you can save loads of energy for solar/wind projects.

john_wage
Posts: 156
Joined: Thu Mar 22, 2012 6:20 am
Contact: Website

Re: Solar powered httpd server

Sat Mar 24, 2012 4:22 pm

ajmas said:


Without the solar panels there is the following battery pack:

http://www.amazon.com/Tekkeon-....._title_def


Pretty good find there. I like the fact that you can upgrade the capacity any time by interchangeable standardized batteries.

Bookmarking this product for later use

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