[thedoc (OP)]

Shah asked the Naked Scientists:
   Hello. My name is shah and I'm from Malaysia. I need your help. In my final project, I want to make a project using heat to get voltage. Is that possible to get 36V output using heat? I watch videos on YouTube that make free energy using heat. I just need 36V but the higher voltage output would be better. Can you help me?
For an example.
 www.instructables.com/id/Adjustable-Voltage-Step-up-07-55V-to-27-55V/
In this project. They are using heat to produce voltage but the output is only 5.5Vdc. In my project, I need 36Vdc  using the same method which uses heat. Maybe I need to use a step up transformer and voltage regulator but I don't really understand the circuit. Can you help me? I hope you can help me and give me a simple answer that I can understand. A schematic circuit would help me understand better. I hope you can help me.

 
What do you think?

[evan_au]

Is that possible to get 36V output using heat?

Yes, it's possible.
But as well as knowing the output voltage, you also need to know the output current. Multiplying voltage x current will tell you how much power you need.

And you also need to know the input heat source - the maximum temperature you can obtain from it.

The efficiency of converting heat to electricity is not very good when you do it on a small scale, so you may need to be content with having 10 to 100 times the input power, compared to the output power.

You can use a DC-DC converter to turn 5.5V into 36V - but by increasing the voltage by a factor of 7, you decrease the current by a factor of 7 (and lose some more in conversion losses). So knowing the output current required is vital in doing this design.

make free energy using heat

Energy is never truly "free". Someone needs to pay for the source of heat.
And when you want more energy, you have to pay for more heat.