Analysis: New research is examining the use of thermoelectric materials from renewable sources, such as wood, to convert heat into electrical energy
Heat surrounds us everywhere, whether it is from industrial processes, cooking in our kitchens, or simply from our bodies because of daily activities. Amazingly, much of this heat is wasted, dissipating into the atmosphere without being harnessed for any productive use.
But what if we could capture even a fraction of this wasted energy and turn it into electricity? It's an unqiue idea that holds immense promise for a more sustainable energy future, reducing our reliance on finite resources.
An innovative and novel technology called thermoelectric materials are capable of directly converting heat into electrical energy. However, the materials traditionally used in these devices - such as cadmium, tellurides or mercury - present a significant drawback. These toxic elements pose environmental and health concerns, limiting the widespread adoption of thermoelectric technology. Despite these challenges, research is ongoing to develop new, eco-friendly thermoelectric materials that are just as efficient but free of harmful components.
From UCC, how to turn waste heat into electricity
One promising avenue is the use of thermoelectric materials derived from renewable sources, such as wood products. A new study by researchers at University of Limerick has revealed a sustainable method of efficiently converting waste heat into electricity using Irish wood products, while minimising costs and environmental impact. The study has demonstrated a method of generating electricity using low-grade heat recovered from lignin-derived thermoelectric material.
How does it work?
Typically overlooked, lignin is a sustainable byproduct derived from wood in paper and pulp production. Our study shows that these materials can convert low-grade waste heat into electricity by utilising the movement of charged atoms (ions) within the material.
Low-grade heat refers to waste heat generated at temperatures below 200 degrees Celsius. In industrial processes, 66% of the waste heat falls into this category, highlighting the potential of this breakthrough for developing sustainable heat-to-electricity applications. Previous studies had only demonstrated this technology using cellulose from natural wood so it's a significant advancement to successfully apply it to lignin from waste wood.
From TMW Photography, what is the thermoelectric effect and how does it work?
How could this be used?
The potential applications of this new thermoelectric technology are wide-ranging and impactful. Industries that generate significant amounts of low-grade waste heat, such as manufacturing, stand to benefit greatly from its implementation. By converting this waste heat into electricity using lignin-derived materials, these industries can improve their energy efficiency and reduce their environmental impact.
Furthermore, the versatility and scalability of this technology mean it could find use in various settings, from providing power in remote areas to powering sensors and devices in everyday applications. Its eco-friendly nature also makes it a promising solution for sustainable energy generation in buildings and infrastructure.
What about energy storage?
Capturing energy is only part of the equation and storing it effectively is equally crucial. Carbon-based materials are commonly used in making electrodes for supercapacitors, which are crucial for storing this energy. However, these carbon materials are mostly derived from fossil fuels, which brings about certain problems. While they work well, using them raises environmental and sustainability issues due to their origin. To tackle these challenges and move towards a greener approach to energy storage, it is essential to explore alternative materials and sustainable practices.
This means your smartwatch, heart rate monitor or GPS tracker could potentially run indefinitely fuelled by your own body heat
Our research team found a novel way of synthesizing porous carbons out of lignin. These porous carbons were made without use of any chemical treatment making them sustainable and environmentally friendly solutions. These lignin-derived materials can effectively be utilised as electrode materials in batteries and supercapacitors to store energy.
Researchers are now trying to sandwich both these technologies together using sustainable materials, so that they can produce a device that can generate and store energy at the same time. Such devices would act like tiny built-in power banks, seamlessly integrated into your wearable tech. This means your smartwatch, heart rate monitor, or GPS tracker could potentially run for extended periods, or even indefinitely, fuelled by your own body heat. This exciting development holds immense promise for the future of wearable technology.
The full NXTGENWOOD study, which has been funded by the Department of Agriculture, Food and the Marine, has been published in Advanced Functional Materials. The report on synthesizing porous carbons out of lignin is published in ACS Sustainable Chemistry & Engineering Journal and is also funded by Department of Agriculture, Food and the Marine under the NXTGENWOOD project
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The views expressed here are those of the author and do not represent or reflect the views of RTÉ
