Waste heat recovery with the most abundant element: Silicon

Waste heat recovery with the most abundant element: Silicon

Large amounts of waste heat generated in our fossil-fuel based economy can be converted into useful electric power by using the so-called thermoelectric generators. These power generators use temperature differences to generate electricity in a very simple and straightforward way. However, the low-efficiency, high-cost and scarcity of conventional thermoelectric materials are hindering a massive deployment of this energy harvesting technology to recover residual heat.

Nanoengineering has proven to be an excellent approach for enhancing thermoelectric properties of abundant and cheap materials such as Silicon. Nevertheless, the implementation of these nanostructures is still a major challenge especially for covering the large areas required for massive waste heat recovery, for instance, at the industry level. We have been working in developing a novel family of nano-enabled silicon-based materials in the form of large-area paper-like fabrics made of nanotubes. Our recent paper in Nature Communications presents this as a cost-effective and scalable solution for thermoelectric generation opening new markets with a potential for recovery up to 15TW of currently wasted power. 

The image shows a cross-section Scanning Electron Microscopy picture of our thermoelectric fabric made of Silicon nanotubes. This is how our new nanomaterial looks like from inside!


A. Morata, M. Pacios, G. Gadea, C. Flox, D. Cadavid, A. Cabot & A. Tarancón, “Large-area and adaptable electrospun silicon-based thermoelectric nanomaterials with high energy conversion efficiencies“, Nature Communications 9 (2018) 4759