In a groundbreaking development that fuses chemistry with renewable energy, Professor Grace Han from the University of California, Santa Barbara, has drawn inspiration from an unlikely source: sunburn. Her innovative research into molecular solar thermal (Most) energy storage is poised to revolutionise how we store and utilise energy, potentially offering a sustainable alternative to traditional fossil fuels.
From Sunburn to Scientific Discovery
Professor Han’s journey into this fascinating realm began with a personal experience. Moving from Boston to the sun-drenched climes of southern California, she quickly recognised the intensity of the sun’s rays. “I had to adapt my routine,” Han recalls, donning wide-brimmed hats and slathering on sunscreen. During her time in California, she stumbled upon a concept that would merge her fascination with chemistry and the sun’s energy.
While indulging in some light reading on DNA photochemistry, Han made a pivotal connection. She realised that DNA in human skin, which suffers damage from UV exposure, changes its shape when exposed to sunlight. This property could be harnessed to create efficient energy storage systems. Scientists have long sought materials that can twist and revert their shape while storing energy—akin to setting a mousetrap and later releasing it. This is where Most technology steps in, presenting a promising, emission-free method of storing thermal energy for extended periods.
The Science Behind Most Technology
For decades, researchers have grappled with the challenges of energy storage, but Han’s approach is turning heads. The key to this technology lies in activating the shape-shifting capability of certain molecules. Nature itself has mastered this process over millions of years, particularly in specific plants and animals that utilise an enzyme known as photolyase to repair sun-induced molecular damage.
“This enzyme makes these molecules ideal candidates for energy storage,” Han explains, noting their minuscule size and immense energy storage capacity. Her recent study, published in February, showcased an energy storage system that achieved an impressive density of 1.65 megajoules per kilogram—surpassing the capabilities of current lithium-ion batteries.
During the research, her students were thrilled to see their experimental setup boil water in a tiny kettle, a clear indication of the system’s potential. “When I saw the video of the solution boiling so rapidly, I was truly amazed,” she adds.
A Bright Future with Challenges Ahead
While the results are promising, Han’s team faces several hurdles. The energy-storing molecules rely on 300-nanometre UV light to change shape—an intense wavelength that is not abundantly available from the sun. Additionally, the current method for triggering the release of stored energy involves hydrochloric acid, which poses environmental and safety concerns. “It’s not the most ideal choice,” Han admits, expressing hope for future advancements that could allow for natural light activation and a non-corrosive trigger.
The overarching goal of this research is to decarbonise heating—a notoriously difficult sector to transition away from fossil fuels. Unlike traditional energy sources, Most technology can be deployed anywhere on the planet, making it a viable solution for global energy needs.
The Path Forward: Innovations on the Horizon
Experts in the field, such as Kasper Moth-Poulsen from the Polytechnic University of Barcelona, have praised Han’s results. He notes that while their best systems have reached one megajoule of energy per kilogram, Han’s achievement stands out in the landscape of energy storage innovation.
Yet, challenges remain. The molecular structures must be spread thinly to ensure effective light penetration, and the logistics of moving liquid energy storage can complicate the system’s design. John Griffin from Lancaster University is working on solid-state iterations of Most technology, which could lead to applications in transparent window coatings capable of warming spaces or preventing condensation.
While some researchers remain cautious about the ability of Most systems to fulfil all heating requirements for buildings, their potential for niche applications—such as warming temperature-sensitive components in satellites—remains significant. “It’s great science,” Griffin affirms.
Why it Matters
This pioneering work in molecular solar thermal energy storage represents a significant step towards a sustainable energy future. As the world grapples with the realities of climate change and the urgent need for cleaner energy solutions, innovations like Han’s could provide key alternatives to fossil fuels, democratising access to energy and reducing our carbon footprint. The journey is just beginning, but the promise of a brighter, more sustainable energy landscape is on the horizon.