My project is that I want to USB fire charger. Its a device that you place on or near fire that will use the Seebeck effect of a pelteir plate to charge a USB device. So far I learned that i will only get 1.2 volts from a pelteir connected with a Schottky diode. USB ports need 5 V to charge any device. I looked online on ways to step up voltage and the thing i found is a charge pump. Is the only way to step up voltages from 1.2 V to 5 V. I also found this link that steps up a solar panel voltage to 5 V, could the panel be swapped with a pelteir plate. (http://www.talkingelectronics.com/projects/SolarLight/PowerSupply5vSolar.html) Thank you for your replies in advance.