Mapping technological advances on energy efficient components. The case of domestic appliances

The present study uses an original dataset on four large energy-efficient (EE) appliances and provides a methodology for:i) mapping components related to energy efficiency improvements; ii) mapping their evolutionover time; iii) testing technological fungibility of those components. Our analysis model exploits an original patent selection process and the concept of technological relatedness using co-occurrences analysis of patent classes as an input for Self-Organising Maps -an unsupervised artificial neural network able to represent high-dimensional data in visually-attractive and low-dimensional distance-based maps. The results confirm the pervasive nature of EE to be nested in many technological components. In addition,weshowthat a de-materialisation process affected the evolution of EE technologies over time, in a technological space characterised by high level of complexity and variety