Solar Powered ATX Power Supply Unit.




I used an 80plus platinum certified atx psu for my home Controller pc. This machine is a 6 core heavy computing setup and is also always on. On idle I used approximately 80 watts and max load was 125watt. I wanted less power consumption without having to buy a new pc. Read on for my solution.

Step 1: Remove Old AC Powered Atx and Install DC Powered Atx.

Notice the size difference. The m4 atx supplies 250 watts max at 94percent efficiency. The 12 volt cpu connector is a single 4pin plug which is good enough for my setup. I need 12V and 5v for my home automation and communications devices so I pushed out one molex plug for this purpose.

Notice the m4 atx is in an enclosure specifically made for it. All of this from Amazon.

Step 2: Solar Efficiency and Excellent Completion.

The first pic is maximum load whereas the second is idle. The pc and attached devices consume approximately 30 watts less at idle and 20 watts less at maximum load.

You must note that I power my pc from my solar battery bank of 25.6v. If you use a AC DC adapter then your efficiency will not be as high but should be higher than most atx supplies.



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    15 Discussions


    Question 1 year ago on Introduction

    How do you modify an atx psu to accept 36 to 40 v from a solar panel or battery bank to run a computer?

    2 answers

    2 years ago

    Greetings all...

    The only way you will rune a big gaming machine off of solar is to invest in a REALLY GOOD QUALITY inverter of AT LEAST TWICE the power in watts you expect to draw with your computer's power supply. Some of the gaming PC's I've come across will draw in excess of 750 watts! You'd need at least a 1500 watt inverter to power these monsters.

    Another word to the wise (my own experience!) Get a good generator to back up your solar system! I live in the Pacific Northwest of US and this winter we have been hit with a bunch of cloudy days that didn't charge my system too well! The generator took up the slack.

    By the way, Mjtrinihobby, your instructables are first rate! Thanks for doing them!

    Mr B

    1 reply

    Reply 2 years ago

    Aww thanks Ed! Yup your comment is completely valid for ac powered computers. I just needed the added reliability of pure dc power for my home automation pc.


    Reply 4 years ago

    Yes most definitely. The m4 hv atx I used is a wide input voltage supply from 6v to 34v. The higher the voltage the smaller the wires you can use which is cost savings!


    Reply 4 years ago

    Sadly no. This is the highest power unit. I doubt there will be anything bigger than the m4 since it had been in production for several years.

    for high end video cards the m4 definitely cannot work. If you use mid to low end card then perhaps. I gave up on high end gaming some years now. When I play my few select FPS, I used low to mid settings on my AMD R7 240 and I still enjoy the game (although the eye candy is not all there). My drive is energy efficieny now so best effects gaming is out the window! LOL.

    im on an e8500 core 2 duo cpu an a amd 4890 gpu so not high end but doo well but i think pulls more power then the 12 volt unit can offer

    I know I am a little late to the party, but nvidia has some very power efficient cards. I just sold my 280x and purchased a 750Ti which pulls a very svelt ~60 watts max, and is capable of some VERY good performance. If you can undervolt your cpu and underclock it as well as ditch any external hard drives, you might just get away with it on 250w. (I live in an RV with 200watts of solar).