Technology

A time of waste, not a waste of time

 By Amanda Saint

At the 2015 Eni Awards, the Renewable Energy Prize, which recognizes internationally significant research and innovation in the field of renewable energy sources, went to Professor Mercouri Kanatzidis for his work creating energy from waste heat using nanostructured thermoelectrics. This process dramatically lowers the thermal conductivity of the composite and greatly enhances the conversion efficiency. Waste-heat recovery with thermoelectric power generators, how Amanda Saint explains, can improve energy efficiency and provide distributed electricity generation…

Prof. Kanatzidis is currently wearing many hats as a Charles E. and Emma H. Morrison Professor in Chemistry at Northwestern University; Senior Scientist, Materials Science Division at Argonne National Laboratory; and Professor of Materials Science and Engineering, also at Northwestern University. He has been working on synthetic design and prediction of new phases, especially those that can cause disruptive changes in scientific thinking and in technology, since the 1980s; and the results are captured in more than 850 research publications and over 20 patents.

Throughout his career so far, he has generated seminal work and the advancements he has made in his thermoelectrics research have broken the 40-year old record of efficiency in creating electricity from waste heat and have created the potential for technologies to be developed that could generate up to 50GW of energy for use worldwide.

Commenting on the award win, Prof. Kanatzidis said: “This is a humbling experience because of all the other luminaries who have won this award before me. I also feel very honored and excited that the Awards Selection Committee have recognized our long standing research in energy harvesting and conversion using thermoelectric materials as being very important in the field of renewable energy. They have conveyed the message to the energy community that it is not only about solar, wind and hydro, but also about waste heat.”

In fact, the energy world is getting pretty excited about the potential of waste heat as recent advancements in thermoelectric materials, which involve nanostructuring semiconductors, have highlighted the technology’s potential for energy efficiency and heat management on a commercial scale. The nanostructuring Prof. Kanatzidis and his team have been working on has seen them embed nanocrystallines inside a thermoelectric material. He said: “This process dramatically lowers the thermal conductivity of the composite and greatly enhances the conversion efficiency. Waste-heat recovery with thermoelectric power generators can improve energy efficiency and provide distributed electricity generation.”

What this means is that energy-intensive industries, such as cement making, glass making, coal-fired power plants and metals production, for example, all of which generate enormous amounts of heat, can use it to power their processes. Currently, most of the heat generated in these industries is lost into the environment through smoke stacks and other means. Thermoelectric devices are a very attractive proposition for them because they convert thermal energy into electricity without requiring moving components.

“To realize this potential and improve thermoelectric power generation feasibility, the gap between thermoelectric materials development and generator systems engineering must be closed.” Prof. Kanatzidis explained. This is where his work has delivered the breakthrough we need and the basis for further development of veritable thermoelectric generators has been provided.

As well as enabling more energy efficient power generation for the power and manufacturing industries, which are the two biggest carbon emitters worldwide, this breakthrough also has the potential to transform and improve the carbon emission performance of the automobile sector, which has the third largest carbon emissions.

What this means is that energy-intensive industries, such as cement making, glass making, coal-fired power plants and metals production, for example, all of which generate enormous amounts of heat, can use it to power their processes

The numbers really are something to get excited about too. “Automobile exhaust has a high thermal energy content, which is being lost to the environment. In fact about 70% of the energy contained in gasoline or diesel is lost out the exhaust pipe of a truck or car. If even just a fraction of the energy is captured and converted to electricity and used to propel the vehicle, there could be larger saving in the burning of fossil fuels. This will result in substantial carbon savings.” Prof. Kanatzidis said.

So the technologies that can now be developed from his research mean we can dramatically improve the environmental performance of vehicles while the automobile sector works on creating the long-term solutions for moving completely away from petrol and diesel-powered cars.

Looking ahead on how to take the breakthrough to the next step, Prof. Kanatzidis said: ” We are working hard to advance our fundamental understanding of thermoelectric materials science so we can further boost the efficiency of thermoelectrics. The higher the efficiency goes, more and more heat harvesting applications become viable.”

With so much of the things we do in our everyday lives generating huge amounts of heat, the potential for easily harvesting what we need to dramatically cut our carbon emissions is now looking likely to happen sooner rather than later.

about the author
Amanda Saint
Journalist and content writer, specialised in engineering and technology with a focus on environmental sustainability, urbanisation and biotechnology.