Recycling CPUs Processor Heat





Introduction: Recycling CPUs Processor Heat

About: I build products which solve real world problems.

This Project involves conversion of waste heat released by the processor of the computer to Electrical energy using the peltier Effect.
The electricity is generated by the peltier tiles which are placed across temperature difference between the bottom of the laptop, which is hot and the ambient air which has a moderate temperature.

I chose to do a research on the peltier effect as I had earlier heard from people that a lot of heat is wasted which is generated by the processor. Today we are mostly using non-renewable sources of energy to generate electricity which will be depleted in the next 50 years. So I decided to recycle heat generated by the computer processor as I had studied “Law of conservation of energy” which says that energy can neither be created nor destroyed but can be converted from one form to another.
In the peltier module, when one side is heated and other is cooled, through the temperature difference it generates electricity.
I had calculated the area of bottom of the laptop and calculated the area needed to recycle energy. My project has generated about 1.2V en the first build. This voltage was enough to run a USB computer fan.
I have took 12 peltier tiles and placed them on a top of a Gel pack. On above the peltier tiles There was the bottom of laptop.

If this technology is further developed, we can save over 50%-70% of the battery life and thus save electricity.

Question / Proposal-
Hypothesis: If I can capture enough heat from the processor of computer and convert it efficiently to electricity, then I can save the battery lifetime.
Objective: To make a processor heat recycler that generates electricity using the heat generated by the processor.

Step 1: Technical Design

Now, we will see the technical design of this project.

Firstly, We need a heating source and secondly we need a cooling source. In my case, the laptop's processor is the heating source and the Gel pack is the cooling source.The electricity is generated by the peltier tiles which are placed across temperature difference between the bottom of the laptop, which is hot and the ambient air which has a moderate temperature.

When the heat is transferred from the laptop to the gel pack, electrons flow and generate electricity.

Step 2: Materials

Here is the list of materials you need for this project-

1) A Gel Pack

2) TEC Peltier Modules [TEC-12704 or TEC-12706]

3) A set of wires

4) A Laptop

5) A USB computer Fan

6) A laptop Pin [Optional]

7) A Multimeter [Optional]

Step 3: Construction of the Circuit

In this step, we will join all Peltier modules together and connect everything together.

Now place the peltier tiles on the Gel pack. Connect them using wires in series. The peltier tiles should be placed in such a arrangement that it covers all the area of the gel pack.

Step 4: Connecting the Charger and the Fan

Firstly connect the voltmeter to check if the current is flowing.

Now, Connect the laptop pin and the fan to the circuit. Make sure they are in parallel to each other.

Step 5: Testing the Project

Now, place your laptop above the peltier tiles just as shown in the video. Now your fan would run.

You can also charge your laptop by connecting the laptop pin to the circuit.

Congratulations! Now you are one of the person to successfully recycle computers processor heat and turn it into electricity.

Step 6: Results & Conclusion


The results prove my hypothesis, I had tested the project when the temprature of the laptop was high and when it was low.

Temperature Difference (T1 - T2) 17C 25C 35C 48C 58C 79C

Voltage 0.76V 1.2V 1.9V 2.2V 2.4V 4.02V

Now i calculated that how much efficient was my project to save power. So i found that it saved about 30%-40% of the laptops power.


In conclusion, I succeeded in generating electricity from the heat released by the processor.

I have proved my Hypothesis that I can capture enough heat from the computers processor and convert it efficiently into electricity.

I have tested my project several times and this is the proof


Main power supply-
100% in 4 Hours --1

Recycled Heat supply-

36% in 4 Hours --2

Adding both (1+2)-

136% So 100% charged in 2.7 Hours

So I have proved my Hypothesis





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    61 Discussions


    1 year ago

    lol g3t r3ckt

    a student cant get ur project copy....for reading ur innovative ideas because of ur payment.....sir so i kindly request u to give ur papers free for poor students as open source will help sir... please its my humble request....

    Great instructable! I built a similar system that is self powered off of the computers waste heat! And I was able to reach core tempatures of 4.2 degrees Celsius!

    Sure he did something but he did it wrong and refuses to listen to anyone else.

    2 replies

    And what was done wrong? All I see is a great idea that worked and I am now determined to figure out how to use. Wattage would be a nice thing to see, but please don't turn offensive for any reason.

    Could you tell me where you got all the peltier modules, and for how much? And I'm sorry for sounding a little dumb, but could anyone help and explain how he connected the wires together and to the fan/computer?

    1 reply

    Looks like the peltier modules are in Series. Meaning the + and - are chained together.

    Perfect, if all you wanted to do was power a fan for free.... i love it

    The gel pad will also heat up over time, thus reducing the efficiency of the heat exchange.

    I am no electrical expert, but I can see that the 'ible demonstrates a useful idea. If there is any saving however small, I could suggest that it has demonstrated potential and needs further study. Take into account with regard to the cooled gel pack whether it was cooled outside in cold weather (free cooling), whether there was a loss of heat in bringing the gel pack inside the house by opening the door, AND if the heat produced by the computer offset (however miniscule) the amount of heat desired from the home heating system to bring the interior temperature of the house to the desired level. You can offset your heating costs with incandescent bulbs because they produce heat as well as light, but while you pay less for gas, solar, geothermal or other heat, you will pay more for hydro in the process. You might as well try doing the same thing with computers or other appliances. Just saying.

    Hi ssarthak598,

    Its a very nice project, but as the fellow commentators have pointed out your efficiency calculation appears to be off. Aside from the argument based on known efficiencies for peltier effect devices(the thermoelectric effect is very inefficient) we can run the numbers easily too. A modern computer processor in today's laptops draw power at around 30W. So 36% efficiency would amount to recapturing 10.8W as electricity. You can show that even with a perfect heat engine that the maximum theoretical efficiency is Eff= 1-T_c/T_h ==> (T_h-T_c)/T_h. Given your temperature ranges above(remembering to use kelvin) that gives a theoretical max of 22%. You don't have to believe the theory blindly if you don't want to. Measure the amperage and calculate the electrical power using P= I*V and I'm sure you'll see a number much lower than 22% even.

    Again, its a nice project but its important to have the correct perspective when analyzing the things we make.

    I think you did a great job no matter what all the downers say about it.. At least you got away from the lazy and just talk like most of the downers are and did something to investigate,,, I think this approach has great possibilities ... Double plus good again,,,

    2 replies

    Volts are worthless if there are no amperes behind. The voltage you measured are the idle voltages and not loaded voltages. Connect a reasonable resistance for a DC/DC-converter like 20Ohms to the peltiers and measure the voltage AND the current (at the same time with 2 multimeters). This way you get the wattage produced by a peltier of yours. And wattage is what counts.

    Then if you have this, you can check the watt-hour of your battery and do a first calculation:

    Lets say every peltier generates about 1W of power (which may be a bit high but anyway) and your Battery has 95Wh (My HP notebook has such a battery). Also say the total DC/DC-conversion gets made very well and you get 90% from the Peltiers to the 18V your notebook needs. Then again 80% efficiency from 18V powersupply of the Notebook over charging-controler into the battery... Leaves you at 72% efficency from peltier to battery.

    Lets assume that your 12 Peltiers really deliver 1W each so 12W total. With the guessed efficiency of 72% from peltier to battery that would be 8.64W to the battery. 8.64W load-power to a 95Wh battery gives a charge-time of just shy of 11h.

    Under the assumption that your Pelties really provide 1W each (I doubt that... More in the vincinity of 0.2-0.3W) then you could recuperate about the guessed 8-9W from the dissipated heat. If your Notebook uses about 19W like my HP you recuperate about 45% (for 1W-peltier-power each) to 11% (0.25W peltier-power each).

    Both numbers are not too shaby to be honest.

    But to know where we stand, we would need wattage and not idle voltage.

    Also a suggestion: Be sure you have a REALLY goot heattransfer from the Notebook to the peltiers... Looks like you just placed the notebook atop the peltiers... Use heatconducting paste (Attention! Messy!!!) to increase the heatflow from the notebook to the peltiers... Also placing peltiers on a metal table would help to dissipate the heat very efficiently...

    1 reply


    Here I can give you the results after testing my project several times-

    Main power supply-
    100% in 4 Hours --1

    Recycled Heat supply-

    36% in 4 Hours --2

    Adding both (1+2)-

    136% So 100% charged in 2.7 Hours