Energy has been critical to societal development over the history of humankind. Our ability to convert one form of energy to another has revolutionized our lives; for example, solar cells provide electricity from sunlight and have electrified many remote communities that lacked access to traditional electricity. Unfortunately, many of the current energy technologies pollute the environment and rely on limited resources. We simply have to transition away from these technologies to ensure a decarbonized and sustainable future for the growing world population. Based on this broader understanding, the future energy technologies seem obvious—replace coal and gas power plants with renewable energy sources like solar and wind, switch from traditional combustion engine cars to electric vehicles, etc. However, the pace of transition to these technologies across the globe seems to be annoyingly slow.

The Materials Research Society (MRS) along with the MRS Energy & Sustainability and Nature Energy journals recently held a joint workshop titled “Materials Challenges for the Energy Transition” to discuss the ongoing energy transition and specifically what stops us from transitioning to new technologies overnight. Unlike most technological transitions of the past, the global nature of the energy transition renders it uniquely challenging. What happens in one part of the world influences everyone everywhere in a nonlinear fashion. For instance, curbing pollution in the United States alone does not pause global temperature rise if other countries continue to generate power using fossil fuels. Additionally, electricity generation is just one of the causes of pollution. The workshop schedule facilitated global participation of invited speakers from across the globe who have been contributing to different aspects of the energy transition (see Schematic).

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A schematic diagram illustrating various aspects of enabling an energy transition. Although there are many additional aspects to enabling the sustainable energy transition (e.g., financial support and international coalition), this schematic shows only the aspects discussed explicitly at the recent workshop on Materials Challenges for the Energy Transition. The size and color of the individual shapes do not have any special meaning.

Many energy technologies are necessary for such a transition. Sally Benson from the White House Office of Science and Technology Policy discussed the multiplicity of energy technologies critical to such an energy transition based on a recent White House report (https://www.whitehouse.gov/wp-content/uploads/2022/11/U.S.-Innovation-to-Meet-2050-Climate-Goals.pdf). She also emphasized the environmental justice aspect to energy transition: electricity bills represent a much higher fraction of household income for poorer communities and in turn disproportionately affect their lives.

Interestingly, many energy technologies rely on each other for energy transition. To explain this aspect, Jun Liu from the Pacific Northwest National Laboratory argued that nonpolluting forms of energy generation—for example, wind and solar—are qualitatively different from the traditional centralized power generation. These new energy sources are intermittent and often not centralized. Consequently, they have to be coupled with batteries and other energy storage technologies such that electricity is available even when the sun is not shining or the wind is not blowing. However, we still have to figure out the materials and engineer new kinds of batteries to store energy for hours, days, or even months.

Apart from renewable energy generation and battery-based energy storage, we also have to innovate new technologies for producing carbon-neutral fuels like hydrogen and other useful chemicals. Kazunari Domen from The University of Tokyo shared his research on hydrogen production by directly using sunlight. He and his colleagues have developed photocatalyst materials that efficiently use solar radiation to split water into hydrogen and oxygen. Their ongoing efforts center around engineering these materials into large-scale plants. Apart from the engineering problems, such a scale-up also invokes manufacturing challenges across scales. Synthesis and manufacturing at scale is a recurring theme for many future energy technologies. For example, solid electrolyte-based batteries are an important future technology but as Jennifer Rupp from the Technische Universität München showed, fabricating these electrolytes to be thin enough to store more energy than the present-day batteries is not easy. An additional complexity is to fabricate such materials into large area sheets with acceptable manufacturing defects to be a cost-efficient battery technology.

Along with enabling energy technologies that do not cause a negative environmental impact, we also have to ensure that future industries that build these technologies and produce useful materials do not cause pollution during these processes. Mercedes Maroto-Valer from the UK Industrial Decarbonisation Research and Innovation Centre discussed such a transition for United Kingdom-based industries. She outlined strategies ranging from the use of sustainable and/or carbon-neutral fuels like biomass and hydrogen to using electric heating (instead of burning fuels to generate heat), to immediately capturing the pollution from these industries (instead of the less efficient energy-intensive pollution removal from the atmosphere). She advocated that there is no unique solution to achieving a decarbonized industrial sector and we must seek solutions specific to different contexts.

Another important piece to the future of energy technologies is the availability and sustainability of the raw materials necessary to build and operate these devices. As Morgan Bazilian from the Colorado School of Mines pointed out, this is not only a scientific problem but also a geopolitical issue. He discussed related dilemmas with often unexpected factors influencing the outcomes. For example, companies commercializing new technologies typically want steady policies, but the policies and priorities change constantly due to shifting governments as well as global events like wars. He championed the idea of focusing attention on pathways instead of goals to ensure continuity and progress across such factors. Complementing this perspective, Min-Ha Lee from the Korea Institute of Industrial Technology discussed how the South Korean government has incentivized growth in new energy technologies. South Korea is currently the second largest battery manufacturer in the world. They have launched a battery alliance to coordinate governmental policy and industrial development in three key areas: (1) securing a mineral and materials supply chain, (2) building a high-tech innovation hub, and (3) creating a sound domestic ecosystem. Alessandra Hool from the Entwicklungsfonds Seltene Metalle (the ESM Foundation) reminded us that in addition to enabling new energy technologies, we must also focus on their circularity. Setting up circular strategies is not just a technological issue but also a systematic one relying on a good network of interacting entities, policy incentives, and such.

In summary, although the vision of a pollution-free sustainable future is reasonably clear, we have yet to answer many scientific, engineering, political, and other related questions to build the corresponding energy technologies. An additional constraint is that we have to enable these new technologies over considerably shorter time frames than historical estimates for commercializing new science into technology. As Y. Shirley Meng from The University of Chicago, one of the moderators for the workshop, underscored: “We hope this is just a start of the dialogue at MRS and elsewhere to solve these challenges.”