In quantum physics, measuring a quantum system can strongly perturb its state. Originally, such perturbation also affects the system’s energy. A new kind of nano-engine has recently been theoretically proposed to extract work from these energetic fluctuations of purely quantum nature. The device provides a new quantum version of the famous Maxwell's demon engine. The proposal could be implemented with state-of-the-art superconducting circuits. It provides a first step towards evidencing the energetic footprint of quantum noise, and assessing the energetic cost of quantum information technologies.