As of today, energy is a critical resource across the whole spectrum of software systems. According to the International Technology Roadmap for Semiconductors, at the current rate of increase, the total energy required by 2040 by ICT will be over 1020 Joules, which is approximately equal to today’s global energy production. Different types of software-heavy systems play a non-negligible role in this growth, ranging from self-driving vehicles, to autonomous delivery solutions, datacenters, and mobile (web) apps. Empirically assessing their energy consumption and establishing evidence-based development guidelines are necessary steps for reducing their environmental impact. In this talk, Ivano Malavolta will present the main methods and techniques for measuring the energy consumption of software-based systems, together with concrete cases in the datacenter, robotics, and mobile development domains.