Conserving energy from a moving door will generates considerable amounts of kinetic energy that can be harvested by active kinetic generators.

As shown in this prototype demonstrating the energy being converted into light.

Using the technology would harness energy for IoT devices, localised lighting solutions and the ability to provide security information without an additional power source, are all areas where smart-cities will benefit from using this new technology.

Emergency Lights

Buildings where several doors might be opened and closed frequently, could harvest and store the energy to power an independent energy source for safety devices or lighting in an emergency.