How much conservation of energy is theoretically possible? To answer this question, we must first know the minimum energy required to perform a particular activity. The difference between this minimum and the current amount of energy consumed for the activity would be — in theory — the maximum amount of conservation possible. Applying principles of mechanics and thermodynamics, we can obtain this theoretical value for energy conservation. One way to do this would be to calculate the theoretical minimum energy for each energy-consuming human activity, such as the production of steel, the manufacture of plastics, and the use of air conditioners, refrigerators and automobiles. This approach, however, would require studying a countless number of activities. Therefore, let’s take another approach here. We will break down the complex human activities into elementary steps and then study the activities where we wish to conserve energy as a sequence of those elementary steps.