# In space can the difference in temperature between the inside and outside, provide useful energy? Tags: energy, thermal - Score: 11 - Views: 1175 - Answers: 2 - Answered: yes - Asked by: James Jenkins (27305 rep) - Asked: 2013-07-28 - Edited: 2013-07-28 - Site: space ## Question The Thermoelectric effect allows for electrical energy to be created, based on a difference of temperature. In fact the Radioisotope thermoelectric generator is based on this principal and does/has supplied energy to several NASA vehicles. Space is cold, and the inside of human occupied vehicle is warm. So if you just made the shell of your ship a big Thermoelectric Generator, and kept the inside at a comfortable temperature, how much electrical energy would you produce? ## Answers ### Answer by AlanSE (score: 11 [ACCEPTED]) This question is intriguing because of the nature of the thermal cycles. This is the maximum theoretical efficiency of a thermal cycle (Carnot cycle), no ifs, ands, or buts about it. You can obtain very low temperatures from space, because space is at a low temperature. You'll often hear the Cosmic Microwave Background (CMB) cited for this, but that's overly optimistic. A rad