Want to reverse climate change or solve world hunger? Try growing algae.

Researchers at the University of Hawai’i at Hilo partnered with faculty at Duke and Cornell University to study algae production with bioenergy with carbon capture and storage (BECCS) technology. They created a model that uses carbon dioxide emissions from burning wood to grow algae, which can be used for fuel or food. 

“It provides a path forward as a solution to reverse climate change without compromising other things that are important, namely food,” said Zackary Johnson, Arthur P. Kaupe associate professor of molecular biology in marine science.

Johnson noted that the protein from algae could serve as a substitute for whey, a protein commonly found in milk. He compared algae protein to fish protein, praising its quality. 

“In preliminary studies, we tested algae as a source of food for a variety of animals: chicken, pig, salmon, shrimp...they [ate] that as a food source and [did] quite well,” Johnson said.  

Although the model is yet to be tested, Johnson estimated that a testing facility would cost around $300 million. The facility would include a eucalypt forest, which would provide the combustible fuel to generate electricity. Conventionally, emitted carbon dioxide would then be released into the atmosphere or buried in the ground, but this model uses a fraction of the captured carbon dioxide to grow algae. 

Johnson said the algae production should offset the carbon dioxide emitted by burning the eucalyptus wood. 

“The algae use far less CO2 overall than a standard food producing technology, whether that's terrestrial crops or otherwise,” he said. “Even that part reduces the overall CO2 footprint. It's a win-win basically. You're not using other technologies that are even more CO2 intensive.”

However, the model is based off certain assumptions that still need to be tested. The unpredictability of the economy also poses a challenge for the team, Johnson added.  

Nevertheless, Johnson is optimistic that governments and companies interested in pursuing BECCS technology will be more open to investing in his team’s new technology. 

“There are uncertainties regarding the costs of CO2 and protein…[but] we think the trajectory is in the right direction,” Johnson said. “We think CO2 will be more expensive [and] people will value less CO2 in the atmosphere more and more.”