Biorefining: the key to kickstarting a seaweed-based bioeconomy

Part 4 of our Exploring Seaweed Series

So if seaweed is a zero-input crop and we have the potential to grow a lot more and bite into $100bn markets, the question remains, why hasn’t it taken off? 

The short answer is: it’s still too expensive to harvest and refine biomass into high performance products. But the long answer is more nuanced and interesting. While the industry doesn’t yet have an exact playbook on how to scale a seaweed-based bioindustry, the pieces of the jigsaw are quite clear.

Multi-product biorefineries

There are few examples of scaled seaweed-based products beyond hydrocolloids. This is because seaweed-based products, with the exception of some speciality compounds, are competing against optimized incumbents. Seaweed protein isolate, for example, must compete head-on with derivatives from soybeans and whey (which are already pretty cheap by the way). 

Generally, the unit economics of producing a single seaweed-based product is rarely competitive vs. existing, often fossil fuel-based, alternatives. Moreover, other sources of biomass may offer lower-cost feedstocks (e.g. fungi for mannitol, methane for PHA/PHB).

But a multi-product biorefinery - where a protein isolate is just one of a dozen co-products - can deliver competitive unit economics which can be commercially scaled. This approach has been pioneered in terrestrial commodities like corn. The trick is to translate it and optimize the “recipe” for the target seaweed species.

Biorefineries require a consistent supply of biomass. The traditional answer has been to vertically integrate (i.e. to process what you farm), but that limits scale and hence competitive unit economics. 

By adopting another model well proven in land-based agriculture - grower cooperatives - seaweed farmers can band together to aggregate supply, invest in dewatering (seaweed is ~90% water) and drying, while the biorefinery can secure sufficient biomass and offer reliable access to markets.

Grower-friendly permitting & capital

In the US, approvals for near-shore cultivation of seaweed are in each state’s purview whilst offshore permits are under NOAA’s control. The state can make life extraordinarily difficult for growers (e.g. California has just issued its first permit for a seaweed farm in more than 25 years!) to relatively easy (e.g. Alaska has approved dozens of permits recently and has put seaweed at the heart of its Mariculture Development Plan). 

In addition, setting up a new seaweed farm requires capital as do nurseries to provide high quality seed stock to growers. Traditional sources of financing are frequently not available to these mariculture pioneers. Some states, like Alaska, are working hard to train would-be seaweed farmers, but more needs to be done to unlock capital for these growers.

Better understanding of seaweed genetics

Governments and industry have spent billions of dollars over decades to improve the yield and resilience of commodity crops like corn, soybeans, wheat and rice. By comparison, seaweed breeding is still in its infancy with Asia leading the way. Only a small number of seaweed genomes have been sequenced and assembled (though work is underway). 

Much is being done to improve seed stock to increase the volume of harvestable biomass. But current commercial strains are not well characterized with biorefining targets in mind; valuable traits can be further explored to optimize yields. 

As we scale up production in the northern hemisphere and offshore, the price of biomass will fall significantly. Yet we must still fund the scientists to study seaweed genetics so we can grow seaweed biomass more sustainably and efficiently.

Kickstarting the virtuous cycle

How do these pieces of the puzzle fit together? The answer: start with seaweed biorefining. By focussing on new, more efficient processing methods, you can derive more value from the biomass. If that is shared with seaweed growers, they will plant more. The more growers plant, the easier it is to invest in genetics, further driving efficiency of production. As the industry grows, governments will adjust permitting, capital will flow, and the unit economics will further improve. 

By successfully transforming seaweed into competitive bio-based products, we can kickstart a virtuous cycle where investment generates technology improvements which in turn enable better products and unit economics and more scale, which in turn brings in more growers, more investment, better technology and so on.

This playbook has worked in other green industries like solar and is well known in terrestrial agriculture where it has played out in numerous commodities like soybeans, sugar cane and processing tomatoes.

Let’s make waves

Seaweed has the potential to be as dominant in the next 50 years of agriculture as corn and soybeans are today. Getting there will take vision, ambition, ingenuity, and luck. But there is already momentum behind us. 

As we warm the Earth’s climate and degrade its biosphere, we must chart a new course. We need to form a more symbiotic, less exploitative relationship with the natural world. Part of the answer is to electrify everything (cars, heating systems, etc), but we must also decarbonize our industrial supply chains and transition to a cleaner, bio-based economy. Seaweed, just like solar before it, offers us an important path towards a greener future.