Thermoelectric Generator DIY

Hi everyone! This Instructable will help you building your own Thermoelectric Generator using thermoelectric coolers (a.k.a. TEC). If you follow each and every step of this tutorial you will be able to generate energy with nothing but fire and water!

What you are going to learn from this Instructable:

1. How TEC work
2. Use TEC to generate energy
3. How to build a Thermoelectric Generator
4. How to take advantage of the Seebeck effect
5. Make fun experiments with TEC ( making ICE and power a MOTOR)

Make sure you watch the video because it´s more illustrative. Subscribe to my Youtube channel so you don´t miss out on new project and to help me grow!

Thermoelectric coolers operate using the Peltier effect. This effect creates a temperature difference by transferring heat between 2 electrical junctions. Applying voltage across joined conductors creates an electric current. When the current flows through the junctions of the two conductors, heat is removed at one side and cooling occurs. Heat is deposited at the other side.

AMAZING SCIENCE EXPERIMENTS

Thermoelectric Cooler explained. How to light up LEDs, power small motor using the Seebeck effect. Also demonstration of the Peltier effect, used to freeze water.

MAKING ICE

If you connect your TEC to a power supply, one side of the plate heats up while the other cools down which is called the Peltier effect.The hot side can get burning hot, so add a heatsink and place it in water to ensure a good cooling. The cold side of this device can reach temperatures low enough to freeze water!

FREE ENERGY

This device can also be used the other way around to generate electricity. By heating up one side of the plate and cooling down the other we can create a voltage difference across the thermoelectric cooling device. This is called the Seebeck effect and that’s what we are going to take advantage of in this Instructable.

Here is a list of the material we need to complete this project:

8 to 10 x TEC

1 x Voltage regulator

10 x Candles

1 x Thermoelectric paste

1 x Aluminium tray

1 x Aluminium plate

1 x Loctite

1 x Insulation tape

Tools you will need:

1 x X-acto knife

1 x Soldering Iron

1 x Solder wire

Lets start by making some calculations. You can go to the Thermoelectric Cooler Technical Data Sheet (TDS) to check the dimensions or simply measure it with a ruler. The dimensions should be 40x40 mm. Before starting you need to decide whether you want to use 8 or 10 TEC. The difference is that 10 will provide more voltage and current than 8. I used 8 TECs so my aluminium tray should have a 160x80 mm base. BE CAREFUL, the base needs to be flat so you can glue the TEC making full contact with it. I first bought a tray with a slight slope and I realized it would not work because we need to take advantage of the temperature gradient and the slope would not allow it.

Once you know where the TEC will be installed, you should insulate the area with an insulation tape as shown in the second picture. Then, apply thermal paste on the blank side and glue it with letters facing up. You will notice that the red and black wires form pairs. We are going to solder them together, except for the TEC number 8 red wire and TEC number 4 black wire which are going to stay loose. To complete the loop, the black wire of TEC number 5 should be soldered to TEC number 1 red wire.

After completing this step we are done with soldering. I advise you to stick more insulation tape over the soldering points to avoid contact with other surfaces.

MAKING THE STAND

We should start by projecting the stand. To do so, we need to take in consideration the dimensions of our tray. My aluminium tray is 230x230x50mm. Lets concentrate on the height (50mm). We need to add 5mm because of the TEC thickness. I consider 15mm to be an appropriate distance between the TEC and the candle flames. We are going to assume that candle + flame is 30mm.

Summing up:

• Tray height + TEC thickness = 50 + 5 = 55mm
• Distance between TEC and flame = 15mm
• Candle + flame = 30mm
• Total Stand Height = 100mm

You should naturally take in consideration your tray's height and then add up the rest of the factors.

I used an aluminum plate to build the stand. You need a 430(100+230+100)x100mm plate, as illustrated on the sketch above. You should bend each line by 90º forming a C.

VOLTAGE REGULATOR SUPPORT

You can easily build a support to the voltage regulator by cutting an aluminium strip of 30x250mm. When this is done, you should ply the edges to fit in the aluminium tray´s sides. I then cut 3 pieces of cork and glued them to the support. The voltage regulator was glued on top of the cork to make sure it is also insulated. You can see the result in picture number 2.

CONNECTING TEC WIRES TO THE VOLTAGE REGULATOR

Conventionally, in electricity, red is positive (+) and black is negative (-). If you use a multimeter to measure the voltage between the loose red and black wires, you will read a negative voltage. This means that, because of the way we soldered the TEC pads, the polarity was inverted. Therfore, we also need to invert the way we connect the TEC pads to the voltage regulator. If you have doubts about this connection please check the picture on top.

LITTLE TRICK :)

To make sure TEC catches more heat from the candles, I used an aluminium plate (160x120mm) and bent down the edges. This piece of aluminium covers more area than the TEC plates, therefore, it is capable of collecting more heat. This step is super important because, as you know, TEC works with temperature difference so, the more heat we collect (with the same amount of candles), the better the result. Now all you have to do is to apply thermal paste on the TECs and then glue the piece of aluminium right on top of it. I used some clamps to make sure it is well glued and let it dry for 12 hours.

Picture number 5 shows how it should look like. It is a pretty stable stand!

To hardest part, which is sketching, making and electronics is done. This is the easy and better part! We are almost ready to start making electricity with these amazing electronic devices.

Lets start by putting as many candles as you can on the support base. Light them up and then install the tray. Thereafter you should pour water in the tray. In my experiment I added some ice cubes the make the water cooler and, therefore, generate more energy. You will notice that soon a small LED on the voltage regulator will light up and then the voltage on the display will start to rise. Good news: ITS WORKING! Wait a minute or two so it stabilizes and then press the button on the voltage regulator. This will set a filter that only allows 5V to pass through the regulator which is what phones usually take in. If you are curious you can also measure the current with a multimeter. The highest the current the faster it´ll charge. You should change the water every 15 minutes to make sure you keep the cool surface cold enough to generate a good amount of energy.

That´s it for this Instructable, hope you enjoyed the project and make sure you subscribe to my Youtube channel to help me grow and keep on doing DIY projects!