Technologies developed under the MARINER program will address marine system design/engineering and integration with biomass production, hydrodynamic and ocean modeling, sensor technology development, macroalgae breeding tools, and field testing of cultivation systems and sensor technologies. Click to enlarge.

The overall goal of this program is to develop the critical tools that will allow the nascent macroalgae (seaweed) industry in the United States to leverage this tremendous resource and grow into a world leader in the production of marine biomass.

The challenge is to reduce significantly the capital and operating cost of macroalgae cultivation, while significantly increasing the range of deployment by expanding into more exposed, off-shore environments.

Specifically, this program is interested in new designs and approaches to macroalgae cultivation, with harvesting and transport being an integral part of such systems. These new systems may leverage new material and engineering solutions, and autonomous and robotic operations, as well as advanced sensing and monitoring capabilities.

To further accelerate the development and deployment of such systems, the program will also focus on the development of computational modeling tools and ocean-deployable sensor platforms, as well as advanced macroalgal breeding tools. ARPA-E expects that the MARINER program will support development of technologies that will accelerate the deployment of advanced ocean farming systems capable of delivering renewable biomass feedstock at a cost competitive with terrestrial biomass feedstocks.

Background. Macroalgae broadly describes a number of green, red, and brown species that can be found in disparate geographic locations across the oceans. Nearly 25 million metric tons (wet) were produced globally in 2014. Macroalgae is primarily used directly as food for human consumption, but also serves as a feedstock for the extraction of naturally occurring alginate, agar, and carrageenan compounds. Beyond these well established applications, there is a growing number of additional opportunities for large-scale macroalgae utilization, from the production of fuels and chemicals to animal feed.

Over the previous 25 years, global production of macroalgae has increased 6-fold, driven by an increasing demand for macroalgae and macroalgae products for food consumption. Even with such impressive growth, 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. This will require a transformational change from the low tech, labor-intensive methods used today, to a technology-driven, marine agronomic industry.

According to ARPA-E, innovative engineering and systems-level solutions along with a suite of critical supporting technologies are necessary to build a commercially viable seaweed industry in the United States, capable of delivering a scalable, affordable, and renewable resource.

A recent assessment (funded by ARPA-E) of global geospatial conditions for potential red and brown macroalgae production considered four primary parameters: water temperature, nutrient concentration, bathymetry, and photosynthetically active radiation. Based on this preliminary assessment, ARPA-E estimates that the US has suitable conditions and geography for producing approximately 200 million dry metric tons (DMT) of brown macroalgae and 300 million DMT of red macroalgae.

Such production volumes could potentially yield approximately 2.7 Quads of energy in the form of liquid fuel—an amount equivalent to roughly 10% of the nation’s annual transportation energy demand.

ARPA-E is committed to the development of transformational technologies to enable a US based macroalgae industry capable of producing up to 2 Quads of bioenergy by 2050, while also supplying the world’s ever expanding need for animal feed. The ARPA-E MARINER Program is intended to support meeting these goals by developing innovative cultivation and harvest systems able to produce macroalgae biomass that is cost competitive with terrestrial biomass at energy-relevant scale.