This spring, ARPA-E awardee University of Alaska Fairbanks (UAF) set out to study critical minerals accumulating in wild seaweed in a remote corner of Alaska. The project is just one of ARPA-E’s ongoing awards to investigate algal mining, a transformative research area using the natural hyperaccumulating ability of seaweed to naturally concentrate rare earth elements from seawater.

Securing critical minerals is crucial for enabling decarbonized energy technologies of the future, but demand for valuable minerals has been outpacing supply. To address this need, ARPA-E is spurring new technologies that could someday become market-ready domestic supplies of critical minerals. 

UAF researchers take in the morning light on their way to collect samples in the waters surrounding Bokan Mountain.

Compared with other ARPA-E critical minerals projects that look to improve existing mining practices, UAF’s approach is more unconventional.  

The project work takes place at Bokan Mountain on Prince of Wales Island in Southeast Alaska. The mountain is the site of a former uranium mine, and is also home to a unique geologic feature: it contains exposed, naturally occurring ore that has high levels of rare earth elements. Rare earths are key components of electric vehicle batteries, wind turbines, solar panels, and many other clean energy technologies, but the United States only has one domestic rare earth element mine.

Bokan Mountain is located on Prince of Wales Island in Southeast Alaska. 

Bokan Mountain’s exposed ore stands tall over forests that blanket the island.  

UAF is studying if rare earth elements from Bokan leach into surrounding coastal waters, and how they potentially hyperaccumulate in wild seaweeds. The location is a natural laboratory to learn hints of how rare earth elements vary naturally in seawater and how environmental factors affect uptake by seaweeds.

Researchers collect seaweed (top) and seawater (bottom left) and processes their samples (bottom right).

Researchers “fish” seaweed by boat or harvest it while snorkeling, as well as collect seawater, stream water, and rock samples. All samples will be later analyzed in the lab, and the team will continue visiting the site through next spring.  

The sun sets over Bokan Mountain.

While the project is hyper-local to start, it will ultimately inform the creation of a computational model to determine the applicability of algal mining in other regions along U.S. shorelines.  

While no algal mining operations exist in the world today, these projects support a nascent technology that could one day transform mining.  

For the last several weeks, ARPA-E has featured innovative work in securing a domestic supply of critical materials for energy, including algal mining and ARPA-E’s long-term investment in critical mineral research. Be sure to subscribe to the ARPA-E Newsletter and follow us on LinkedIn, X, and Facebook to get the latest updates.

Photo Credits: All photos by UAF Marine Team.  Photos of Bokan Mountain in Prince of Wales by Camryn Kaspari.