Figure 5
From: Using defects to store energy in materials – a computational study

Proof-of-concept device designs for releasing the energy stored in defects. (a) Joule heating of a metal using an electric current, and (b) exposing the material (here, graphite) to radiant heat generated by absorbing solar energy. In both examples, the released energy can be converted to electricity via a thermoelectric (TE) device, or employed to run a heat engine or to generate steam by heating up a water tank.