Peltier elements are widely used in various applications all over the world. Nonetheless a lot of different opinions occur when speaking about how the properties of supplied electrical energy influence the short term performance of Peltier elements and how these elements should be driven. Various sources suggest different approaches and there is a lot of discussion if Peltier elements can be driven with pulse width modulated current or direct current should be used. There is recommendation to not exceed 10% ripple of supplied DC Voltage, but there exists other point of view that pulsed nature of electrical power can be ignored if high frequency pulses are used. Series of experiments were made to find out how does the pulse width, frequency and pulsations of direct current affect the heat conduction ability of Peltier element based cooling system. Dependences are presented and compared to theoretical analysis. Study discusses optimal characteristics for supplied electrical power that is required for reasonable operation.