Macroalgae Research Inspiring Novel Energy Resources
The projects that comprise ARPA-E’s MARINER (Macroalgae Research Inspiring Novel Energy Resources) program seek to develop the tools to enable the United States to become a global leader in the production of marine biomass. Presently, macroalgae, or seaweed, is primarily used as food for human consumption, but there is a growing opportunity for the production of macroalgae for use as feedstock for fuels and chemicals, as well as animal feed. ARPA-E estimates the United States has suitable conditions and geography to produce at least 500 million dry metric tons of macroalgae per year. Such production volumes could yield about 2.7 quadrillion BTUs (quads) of energy in the form of liquid fuel, roughly 10% of the nation’s annual transportation energy demand.
MARINER project teams will develop technologies capable of providing economically viable, renewable biomass for energy applications without the need for land, fresh water, and synthetic fertilizers. Such technologies include integrated cultivation and harvesting systems, advanced component technologies, computational modeling tools, aquatic monitoring tools, and advanced breeding and genetic tools. Successful technologies must help greatly reduce the capital and operational expenses related to macroalgae production and enable significant increases in farm size and potential areas of deployment.
In 2014, the world produced approximately 25 million wet metric tons of seaweed through a combination of wild harvesting and highly labor-intensive farming techniques. While macroalgae production has increased six-fold over the past quarter-century, the current state of macroalgae “mariculture” is not capable of achieving the scale, efficiency and production cost necessary to support a seaweed-to-fuels industry. Achieving such productivity increases will require a technology-driven approach focusing on innovative engineering and systems-level solutions and the technologies needed to support them.
Biomass contributes about 5% of U.S. primary energy supply, mostly to produce electricity and liquid biofuels. There are important constraints associated with increased production of biofuel crops on land, including freshwater availability, land availability, material distribution, and logistics. Earth’s oceans cover nearly 70% of the world’s surface area yet supply only 1% of food—even less non-food biomass for human need. Considering the size of the nation’s exclusive economic zone (EEZ), geography, and extent of suitable physical conditions, the United States has the potential to become a world leader in macroalgae production by developing the technologies required to deploy further offshore in the open ocean.
MARINER projects strive to develop the tools needed to allow the United States to become a world leader in marine biomass production for multiple important applications, including the production of biofuels.
Production of biofuels from domestically produced marine biomass could lessen U.S. dependence on foreign oil, bolstering energy security.
Growing large amounts of macroalgae would not compete with land-based food crops, requires no fresh water and can be grown without the addition of energy-intensive, synthetic nitrogen fertilizer. Large-scale macroalgae cultivation may help reduce the negative effects of nutrient overload of many coastal ocean regions.
A domestic macroalgae industry would not only create a valuable new source of domestic energy, but also create significant new economic and employment opportunities in many waterfront communities along the U.S. coasts, from Maine to the Gulf, to Alaska and the Pacific Islands.