  In this document we describe and discuss energy tanks, a control algorithm
which has gained popularity inside the robotics and control community over the
last years. This article has the threefold scope of i) introducing to the
reader the topic in a simple yet precise way, starting with a throughout
description of the energy-aware framework, where energy tanks find their
genesis; ii) summarising the range of applications of energy tanks, including
an original reflection about different formulations of those; iii) discussing
limits and future challenges involving energy tanks and energy-aware control in
general.
