If you’ve ever looked at yourself through a thermal camera, you know that your body gives off a lot of heat. This heat is actually a byproduct of our metabolism. Each square foot of the human body produces heat equal to about 19 matches per hour. Unfortunately, most of this heat is wasted and escapes into the air. Wouldn’t it be great if we could use it to create energy? My research has shown that this is possible. My colleagues and I are working on ways to capture and store body heat for energy production using environmentally friendly materials.
The goal is to develop a device that can generate and store energy, acting like a built-in power source for wearable technology. This could allow devices like smartwatches, fitness trackers, or GPS trackers to run for much longer periods, or even indefinitely, by harnessing our body heat. It’s not just our bodies that produce waste heat. In our modern world, a significant amount of waste heat is generated daily, from vehicle engines to manufacturing machines. Typically, this heat is also released into the atmosphere, missing out on the opportunity for energy recovery. The concept of “waste heat recovery” aims to address this inefficiency. By harnessing this otherwise wasted energy, industries can improve their efficiency and contribute to a more sustainable environment.
The thermoelectric effect is a phenomenon that can convert heat into electricity. This works by utilizing a temperature difference to create an electric potential, generating usable electrical energy as electrons flow from the hot side to the cool side. Conventional thermoelectric materials often contain cadmium, lead, or mercury, posing environmental and health risks that limit their practical use. However, it has been discovered that thermoelectric materials can also be created from wood, offering a safer and sustainable alternative.
Wood has been a crucial resource for human civilizations for centuries, serving as a source of building materials and fuel. Researchers are exploring the potential of wood-derived materials to convert waste heat, often lost in industrial processes, into valuable electricity. This approach not only enhances energy efficiency but also reimagines everyday materials as essential components of sustainable energy solutions.
A team at the University of Limerick, in collaboration with the University of Valencia, has developed a sustainable method to convert waste heat into electricity using Irish wood products, specifically lignin, a byproduct of the paper industry. Lignin-based membranes, when soaked in a salt solution, can efficiently convert low-temperature waste heat into electricity. This innovation presents a significant opportunity for eco-friendly energy solutions, as a large portion of industrial waste heat falls within this temperature range.
Capturing energy from waste heat is just the beginning; storing it effectively is equally important. Supercapacitors are energy storage devices that can rapidly charge and discharge electricity, essential for applications requiring quick power delivery. However, their reliance on fossil fuel-derived carbon materials raises sustainability concerns. Researchers have found that lignin-based porous carbon can serve as an electrode in supercapacitors for energy storage generated from harvesting waste heat, offering a sustainable solution for energy storage from waste heat.
This innovation in energy storage technology has the potential to power various devices, from consumer electronics to electric vehicles. By providing a green alternative that avoids harmful chemicals and fossil fuels, this approach offers a sustainable solution for storing energy generated from waste heat.
