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An unexpected climate solution

Nicholas Witham is the first-place winner of the Wilkes Center Student Innovation Prize, awarded earlier this month at the University of Utah. The competition invited students to propose creative solutions for tackling the climate crisis and give presentations that detail their potential impact, benefits and practicality. Three other prizes, one for second place and two for third place, were also given during the inaugural Wilkes Climate Summit at the U on May 17-18.

A graduate student at the U, Witham is currently pursuing his Ph.D. in biomedical engineering while running his company Gaia Technologies, which makes prosthetic components. For the Wilkes Center Student Innovation Prize, he designed an innovative renewable electric generator that relies on natural fluctuations in the Earth’s temperature.

“The type of generator I’ve designed works with thermo-motive artificial muscles,” he said. “That means that they contract when you heat them. Every day the Earth gets hotter and colder which will make them move, and they can pull on a turbine, generating power. The great thing about this is that cooling also generates power, so you can make energy day and night.”

A headshot of a man with red hair and a bears wearing black-framed glasses.

PHOTO CREDIT: Todd Anderson

Nicholas Witham, Ph.D. student in biomedical engineering.

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This potential for around-the-clock power generation could help to bridge the energy gap that is common with renewable energy sources.

One of the first places Witham hopes to put his generators is in southern Utah where the day-to-night temperature change is ideal for this technology 10 months out of the year. Although natural temperature fluctuations may fail to run the generators some of the time, Witham believes that they could be used to complement existing renewables, such as solar and geothermal energy.

“You can use highly efficient geothermal heat pumps to actuate them without needing to have a temperature change caused by the environment. The excess heat that they are wasting, not spinning a turbine, just cooling down before they pump it back into the Earth—we could use that to increase the energy output of our generators tenfold,” he said.

In fact, installing these generators at pre-existing geothermal plants or solar farms may be the most ideal option to maximize the efficiency and cost of these sites.

“I ran the numbers, and I believe that this could be a solution that could cost less than solar, and you can scale it vertically,” explained Witham. “So, you could use existing solar infrastructure, place the solar panels on top, and any time you want to reinvest in the site without having to run new electric lines to it, you could just stack them higher.”

Not only is the generator a potentially powerful form of renewable energy, but it also incorporates carbon capture into its design. “These are polymer textiles. So, they’re made out of a plastic called linear low-density polyethylene (LLDPE), which is a type of plastic that can be bioderived. That means you can use corn husks to make this plastic as an indirect form of carbon capture. Every kilogram of LLDPE sequesters 3 kilograms of carbon.”

Witham carefully considered the environmental impact of these generators, ensuring that they contribute to carbon sequestering efforts instead of creating more waste. “In the decommissioning of solar panels, for example, you generate quite a lot of e-waste. This system is designed to be recycled and decommissioned in an environmentally safe practice,” he said.

Witham plans to house the entire generator inside a shipping container, and he estimates that one of these generators could be expected to last over 25 years with very minimal maintenance. Due to their self-contained nature, the impact and effect of these units on the surrounding environment is very minimal.

“It’s essentially a big black box that we plan to put in the middle of the desert. I contacted the local EPA office about this to see if there was anything I was missing, and they had no real concerns. Because we’re putting it in a box, any microplastics that might be generated by the textiles shearing or breaking catastrophically would be contained,” he stated.

A device of two sides connected by a spring that looks like it can contract and expand to generate energy.

PHOTO CREDIT: Nicholas Witham

Textile artificial muscle in thermo-mechanical testing set-up.

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The capacity for incorporating these devices in urban areas, according to Witham, may be limited to apartment buildings or skyscrapers. “I don’t think anybody really wants to use a shipping-container-sized portion of their yard to make power,” he joked. The weight of these containers also limits their ability to be placed on top of buildings, as each unit weighs roughly 18 metric tons. However, there is potential for them to be incorporated underneath buildings. “You can absolutely put it underground if you have a heat pump HVAC system to regulate it, but that would be a bit less efficient.” Though the generators wouldn’t function as well as in the remote desert environment that Witham has planned, there is still a possibility for urban incorporation.

With a purse of $20,000 from the Wilkes Center Student Innovation Prize, Witham is one step closer to getting his design up and running at full scale. His lab already has the capability to mass-produce the necessary artificial muscle technology, so a prototype will soon follow.

“The assumption is that we can make a nine-megawatt-hour generator at scale to test it in the field. From there we could make a generator field just like you would see for a solar field. And then with a 2.4-year doubling period—which is typical for renewables in this area—that would mean that by 2050 we would have sequestered and offset a total of 15 million tons of CO2.” Witham’s consideration of sustainability, feasible scaling, and collaboration with other renewables make his design both practical and effective as a climate solution.

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PHOTO CREDIT: Todd Anderson

Nicholas Witham presents his award-winning research at the Wilkes Center for Climate Science & Policy.

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Clearly, the judges of the Wilkes Center Student Innovation Prize thought so. Witham’s design is a unique and impressive fusion of renewable energy with pre-existing biomedical technologies, showcasing that the nature of climate solutions will likely be interdisciplinary. Witham jokes that a sleepless night at work is to thank for his idea to incorporate his biomedical work into a renewable energy source.

“I was having a sleep-deprived night in the lab, as you do as a graduate student,” said Witham, “and I crunched the numbers because I thought, ‘Hey, the Earth heats up!’ I connected all the dots because we use a type of plastic that is a lot more energy efficient and is not typically used for these artificial muscles. And that energy efficiency really allowed this idea to have merit.”

Witham’s creative application of biomedical engineering shows that the most powerful climate solutions may come from unexpected places and that no branch of knowledge is too isolated to make an impact. His impressive design stands alongside dozens of other projects from creative and dedicated students that rose to meet this innovation challenge. With prizes such as this, the Wilkes Center for Climate Science and Policy is leading the way toward creating a powerful forum for interdisciplinary climate solutions and collaboration, essential for tackling a multifaceted issue like climate change.

Find the original story at the College of Science.