Stringfellow says that “Everyone has a lot of stars in their eyes, it’s like a new gold rush,”

 Space-based power stations are turning from an idle dream into a serious engineering prospect, as scientists hope they can take renewable energy into orbit.

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It sounds like science fiction: giant solar power stations floating in space that beam down enormous amounts of energy to Earth. And for a long time, the concept — first developed by the Russian scientist, Konstantin Tsiolkovsky, in the 1920s — was mainly an inspiration for writers.
A century later, however, scientists are making huge strides in turning the concept into reality. The European Space Agency has realised the potential of these efforts and is now looking to fund such projects, predicting that the first industrial resource we will get from space is “beamed power”.
Climate change is the greatest challenge of our time, so there’s a lot at stake. From rising global temperatures to shifting weather patterns, the impacts of climate change are already being felt around the globe. Overcoming this challenge will require radical changes to how we generate and consume energy.
The aim is that solar power stations in space will become a reality in the coming decades
Renewable energy technologies have developed drastically in recent years, with improved efficiency and lower cost. But one major barrier to their uptake is the fact that they don’t provide a constant supply of energy. Wind and solar farms only produce energy when the wind is blowing or the sun is shining — but we need electricity around the clock, every day. Ultimately, we need a way to store energy on a large scale before we can make the switch to renewable sources.
Benefits of space
A possible way around this would be to generate solar energy in space. There are many advantages to this. A space-based solar power station could orbit to face the Sun 24 hours a day. The Earth’s atmosphere also absorbs and reflects some of the Sun’s light, so solar cells above the atmosphere will receive more sunlight and produce more energy.
A space solar array could consist of one large structure, or many smaller ones gathered together (Credit: Nasa)
A space solar array could consist of one large structure, or many smaller ones gathered together (Credit: Nasa)
But one of the key challenges to overcome is how to assemble, launch and deploy such large structures. A single solar power station may have to cover as much as 10 sq km (4.9 sq miles) — equivalent to 1,400 football pitches. Using lightweight materials will also be critical, as the biggest expense will be the cost of launching the station into space on a rocket.
We are currently reliant on materials from Earth, but scientists are also considering using resources from space for manufacturing, such as materials found on the Moon
One proposed solution is to develop a swarm of thousands of smaller satellites that will come together and configure to form a single, large solar generator. In 2017, researchers at the California Institute of Technology outlined designs for a modular power station, consisting of thousands of ultralight solar cell tiles. They also demonstrated a prototype tile weighing just 280g per square metre, similar to the weight of card.
Recently, developments in manufacturing, such as 3D printing, are also being investigated for their potential in space power. At the University of Liverpool, we are exploring new manufacturing techniques for printing ultralight solar cells on to solar sails. A solar sail is a foldable, lightweight and highly reflective membrane capable of harnessing the effect of the Sun’s radiation pressure to propel a spacecraft forward without fuel. We are exploring how to embed solar cells on sail structures to create large, fuel-free power stations.
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These methods would enable us to construct the power stations in space. Indeed, it could one day be possible to manufacture and deploy units in space from the International Space Station or the future lunar gateway station that will orbit the Moon. Such devices could in fact help provide power on the Moon.
Solar energy is already used to power spacecraft, but beaming that energy back for use on Earth would become the next level (Credit: Nasa)
Solar energy is already used to power spacecraft, but beaming that energy back for use on Earth would become the next level (Credit: Nasa)
The possibilities don’t end there. While we are currently reliant on materials from Earth to build power stations, scientists are also considering using resources from space for manufacturing, such as materials found on the Moon.
But one of the major challenges ahead will be getting the power transmitted back to Earth. The plan is to convert electricity from the solar cells into energy waves and use electromagnetic fields to transfer them down to an antenna on the Earth’s surface. The antenna would then convert the waves back into electricity. Researchers led by the Japan Aerospace Exploration Agency have already developed designs and demonstrated an orbiter system which should be able to do this.
There is still a lot of work to be done in this field, but the aim is that solar power stations in space will become a reality in the coming decades. Researchers in China have designed a system called Omega, which they aim to have operational by 2050. This system should be capable of supplying 2GW of power into Earth’s grid at peak performance, which is a huge amount. To produce that much power with solar panels on Earth, you would need more than six million of them.
Smaller solar power satellites, like those designed to power lunar rovers, could be operational even sooner.
Across the globe, the scientific community is committing time and effort to the development of solar power stations in space. Our hope is that they could one day be a vital tool in our fight against climate change.
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Amanda Jane Hughes is a lecturer in energy engineering at the University of Liverpool, where her research includes the design of solar cells and optical instruments. Stefania Soldini is a lecturer in aerospace engineering at the University of Liverpool, and her expertise includes numerical simulations for spacecraft mission design and guidance, navigation and control, asteroids and solar sail missions.
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This article originally appeared on The Conversation, and is republished under a Creative Commons licence. This is also why this story does not have an estimate for its carbon emissions, as Future Planet stories usually do.
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Geothermal brine could become a promising and sustainable source of an essential element for the renewable energy transition (Credit: Cornish Lithium)
By Catherine Early
25th November 2020
Lithium is crucial for the transition to renewables, but mining it has been environmentally costly. Now a more sustainable source of lithium has been found deep beneath our feet.
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Cornwall, 1864. A hot spring is discovered nearly 450m (1,485ft) below ground in the Wheal Clifford, a copper mine just outside the mining town of Redruth. Glass bottles are immersed to their necks in its bubbling waters, carefully sealed and sent off for testing. The result is the discovery of so great a quantity of lithium — eight or 10 times as much per gallon as had been found in any hot spring previously analysed — that scientists suspect “it may prove of great commercial value”.
But 19th-Century England had little need for the element, and this 50C (122F) lithium-rich water continued steaming away in the dark for more than 150 years.
Fast forward to autumn 2020, and a site nearby the Wheal Clifford in Cornwall has been confirmed as having some of the world’s highest grades of lithium in geothermal waters. The commercial use for lithium in the 21st Century could not be clearer. It is found not only inside smart phones and laptops, but is now vital to the clean energy transition, for the batteries that power electric vehicles and store energy so renewable power can be released steadily and reliably.
The lithium-rich waters running deep below the surface have been known about for well over a century — but they are only beginning to be tapped (Credit: Cornish Lithium)
The lithium-rich waters running deep below the surface have been known about for well over a century — but they are only beginning to be tapped (Credit: Cornish Lithium)
Demand has soared in recent years as carmakers move toward electric vehicles, as many countries including the UK, Sweden, the Netherlands, France, Norway and Canada announce a phase-out of combustion-engine cars. In fact, five times more lithium than is mined currently is going to be necessary to meet global climate targets by 2050, according to the World Bank.
But there’s one big problem. Obtaining lithium by conventional means takes its own environmental toll, or rather three: carbon emissions, water and land.
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Lithium is currently sourced mainly from hard rock mines, such as those in Australia, or underground brine reservoirs below the surface of dried lake beds, mostly in Chile and Argentina. Hard rock mining — where the mineral is extracted from open pit mines and then roasted using fossil fuels — leaves scars in the landscape, requires a large amount of water and releases 15 tonnes of CO2 for every tonne of lithium, according to an analysis of the whole lithium production process by raw materials experts Minviro. The other conventional option, extracting lithium from underground reservoirs, relies on even more water to extract the lithium — and it takes place in typically very water-scarce parts of the world, leading to indigenous communities questioning their sustainability.
Extracting lithium from geothermal waters — found not just in Cornwall, but Germany and the US as well — has a tiny environmental footprint in comparison, including very low carbon emissions.
One promise of geothermal mining is that the extraction process requires little to no fossil fuel consumption, and uses less land and water (Credit: Leonardo Soares/BBC)
One promise of geothermal mining is that the extraction process requires little to no fossil fuel consumption, and uses less land and water (Credit: Leonardo Soares/BBC)
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Geothermal brine is a hot, concentrated saline solution that has circulated through very hot rocks and become enriched with elements such as lithium, boron and potassium. In other words, the energy-intensive process of extracting lithium from solid rock is powered by naturally occurring geothermal energy. The brine in the Cornish mines has concentrations of up to 260 milligrams per litre, flowing at a rate of between 40–60 litres (8.1 to 13.7 gallons) per second. That works out as about enough lithium for a typical smartphone battery (2–3g) passing through the production process every few seconds, according to Cornish Lithium’s estimates.
Everyone has a lot of stars in their eyes, it’s like a new gold rush — William Stringfellow
The demand for lithium with a lower environmental footprint appears to be gaining ground. There are signs car manufacturers including Mercedes-Benz and Volkswagen are starting to think about the environmental and social impact of their electric vehicle supply chain, says Alex Keynes, clean vehicles manager at Brussels-based campaign organisation Transport and Environment. Using lithium that is already in circulation — from recycled batteries and electronics — is preferable to mining more, says Keynes. “Given the enormous demand we’re likely to see over the coming years, [it] is going to mean we need some extraction, and recovering lithium from geothermal brine looks very promising,” says Keynes.
The 1864 discovery of lithium might finally be about to bear fruit. Cornish Lithium, a company set up by former investment banker Jeremy Wrathall in 2016, is working on plans to extract potentially significant lithium resources from the brine in the region’s famous mines near Redruth.
It has two main sites under development — one is at a deep geothermal plant, where it is collaborating with the energy developer Geothermal Engineering. The energy firm already plans to produce zero-carbon heat and power from the same hot water that contains the lithium, 5.2km (3.2 miles) underground at the United Downs Deep Geothermal Power Project. The water at this site also has low levels of sodium and magnesium compounds, which is a promising sign as these minerals make lithium extraction more difficult and expensive. In August, the project won £4m ($5.3m) backing from the UK government, allowing a pilot lithium extraction plant to be built in the next couple of years.
Large quantities of lithium currently come from reservoirs in South America, but this method is water-intensive (Credit: Getty Images)
Large quantities of lithium currently come from reservoirs in South America, but this method is water-intensive (Credit: Getty Images)
The second geothermal lithium site sits next door to the United Downs project, and assessments of the potential for lithium extraction at a shallower depth of around 1km (0.6 miles) are underway. The company is also exploring the potential to extract lithium from granite rock in the China Clay region of Cornwall, near St Austell.
The extraction of the lithium from Cornwall’s geothermal waters has been made possible by technological advances in both exploration and extraction, says Cornish Lithium’s senior geologist Lucy Crane.
The team is using a variety of data sources to identify the most likely locations of the lithium. “Cornwall has an amazing mining heritage going back 4,500 years, which means there’s a hell of a lot of information out there about the sub-surface,” she says.
All the clean technologies that we need to combat climate change — whether that’s wind turbines, solar panels or batteries, they’re all really, really mineral intensive — Lucy Crane
Some of the historical maps are hand-painted on large pieces of vellum (animal skin used historically for writing). Cornish Lithium’s archivists take photos of it, and digitally stitch it together so that the geological information can be captured in 3D. That allows data from the 1860s, 1900s and 1960s to be combined and overlaid with modern information from satellites and drones.
“This is a really powerful way of combining datasets, and allows you to efficiently target where you want to do on-the-ground exploration,” says Crane. “Then when we come to drilling, we’re as sure as we can be that we’re going to find something. That’s better from an economic point of view, but also minimises the environmental impact of the exploration process.”
Lithium ion batteries are used to power electronic devices and store energy generated from wind and solar power, among their many other uses (Credit: Getty Images)
Lithium ion batteries are used to power electronic devices and store energy generated from wind and solar power, among their many other uses (Credit: Getty Images)
Technological advances are also helping to make it possible to extract lithium from brine. The team is planning to use a technique called Direct Lithium Extraction (DLE), which has been developed by various companies in the US, Germany and New Zealand.
There are as many as 60 variants of DLE technology, according to Jade Cove, a San Francisco-based advisory firm tracking new mining and energy technology. But the basic process involves using techniques such as nanofiltration or ion-exchange resins — which act like a chemical sieve to selectively collect just lithium chloride (the main form in which the lithium is found in the brine), leaving other salts in the water. The lithium chloride is retrieved from the sieve by, for example, washing the resin beads with pure water and injecting the remaining water back into the ground through boreholes. The lithium chloride is then purified and concentrated to produce lithium hydroxide, which is used to make batteries.
But this is not the only way to get lithium from geothermal brine. In the US, William Stringfellow, director of the Ecological Engineering Research Program at Lawrence Berkeley National Laboratory in the US, is undertaking research for the US Department of Energy on the different methods for extracting lithium from brine. One approach is to extract lithium from brines using solvents designed to collect lithium ions, while others include the use of membranes that only allow lithium ions to pass, and electrochemical separation, where lithium ions are drawn to charged electrodes.
“So DLE isn’t necessarily going to be the only technology, but it’s the first one that’s being applied,” says Stringfellow.
Each method has one main stumbling block to navigate — getting only lithium out of the water. “There’s a lot of other materials in the brine that potentially interfere with the lithium extraction process [such as sodium and magnesium], so you have to control those and remove them,” says Stringfellow.
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The US and Germany are also hotbeds of research and development on geothermal lithium extraction. The area around the Salton Sea, a shallow lake in the centre of California and the second largest geothermal field in the US, has been dubbed “lithium valley”. The California Energy Commission has estimated that the field could provide 40% of global lithium demand.
In research published in March this year, the commission forecast the region’s lithium carbonate supply at more than 600,000 tonnes a year, which could generate US$7.2bn (£5.3bn) a year at around US$12,000 (£8,885) a tonne. The hope is that lithium extraction could not only provide a cleaner, domestic source of lithium for batteries, but also significantly improve the economics of renewable power production from geothermal resources, which currently produce only 6% of California’s electricity and are expensive to develop.
“Everyone has a lot of stars in their eyes, it’s like a new gold rush,” says Stringfellow. “It is an economically depressed area, so people are very excited about the fact that if they get lithium going, it would lead to an economic boom.”
Large-scale renewable generation also requires large-scale power storage if energy is to be supplied steadily (Credit: Getty Images)
Large-scale renewable generation also requires large-scale power storage if energy is to be supplied steadily (Credit: Getty Images)
There is a similar anticipation in Germany, where the Rhine Valley is the centre of the country’s nascent geothermal lithium industry. Lithium and geothermal power developer Vulcan Energy Resources plans to pump hot geothermal brine to the surface, and use the heat to power its lithium extraction process, and feed excess back into the grid.
In November, Vulcan Energy Resources announced that its main site had significant reserves, with lithium concentrations of 181 milligrams per litre. It will carry out a full feasibility study in 2021, with the aim of scaling up to full commercial production of lithium in 2023–24. “We have a resource which is large enough to satisfy a very substantial amounts of the demand in the European markets here for many, many years to come,” Vulcan’s chief executive Francis Wedin told an industry conference in October.
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The Rhine Valley is located in the heart of Germany’s car manufacturing region, a location that would give a lithium plant business advantages in supplying electric vehicle makers. But it also significantly reduces the carbon emissions associated with transporting lithium from overseas, Wedin noted. As a result, the firm plans to market its lithium as “zero carbon”.
Back in Cornwall, zero carbon is also the goal for Cornish Lithium’s production process, which it envisions will be powered by geothermal heat. And if its pilot project proves successful, Cornish Lithium is confident that plants could be developed across the region.
“All the clean technologies that we need to combat climate change — whether that’s wind turbines, solar panels or batteries, they’re all really, really mineral intensive,” says Crane. “We need to make sure we extract these materials as responsibly as possible otherwise it mitigates the reason for building these technologies in the first place.”
In all, it may still be a few years before batteries made using zero-carbon lithium are powering your car, or other devices. But if zero-carbon lithium takes off in the way its champions hope, it could become a powerful example of a mineral essential for sustainable energy, obtained in a sustainable way.
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FUTURE PLANET | ECOLOGY
The seaweed swamping the Atlantic Ocean
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(Image credit: Getty Images)
The shore of a tourist resort in Mexico turns black with seaweed (Credit: Getty Images)
By Isabelle Gerretsen
20th November 2020
A sargassum bloom the width of the Atlantic Ocean caused havoc on beaches, but locals in Mexico and the Caribbean are fast finding ways to turn the seaweed invasion to their advantage.
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In the summer of 2018, an almost incomprehensibly large mass of stringy brown seaweed appeared in the Atlantic Ocean. It stretched from one coast to the other, from the shores of West Africa to the Gulf of Mexico. Spanning 8,850 kilometres (5,000 miles), the seaweed bloom, known as the great Atlantic sargassum belt, was the largest ever recorded. Researchers analysing satellite images of the bloom estimated its mass to be more than 20 million tonnes — heavier than 200 fully loaded aircraft carriers.
While the 2018 event was a record, sargassum blooms have been a nuisance in the Atlantic for some years, where they harm coastal biodiversity, fisheries and the tourism industry in the Caribbean and Mexico. Barbados declared a national emergency in June 2018 after its shorelines were engulfed by sargassum.
And it is a problem that appears to be getting worse in the Atlantic. After analysing 19 years of satellite data, researchers at the University of South Florida found that since 2011 the sargassum bloom has appeared annually and is growing in size.
Residents of Mexican coastal towns face a daunting task to try to clear the mounds of sargassum by hand (Credit: Getty Images)
Residents of Mexican coastal towns face a daunting task to try to clear the mounds of sargassum by hand (Credit: Getty Images)
“2011 was a tipping point. Before that we did not see much sargassum. After that we are seeing recurring, massive sargassum blooms in the central Atlantic,” says Mengqiu Wang of the University of South Florida, one of the team who discovered the Atlantic-spanning bloom in 2018. The blooms are at their largest in June and July, she says.
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Other researchers, such as Elizabeth Johns of the US’s National Oceanic and Atmospheric Administration, agree that 2011 was a tipping point for sargassum in the Atlantic, suggesting future blooms are likely to be even larger. Indeed, a Caribbean research cruise in autumn 2014 recorded sargassum concentrations 10 times that of the 2011 event, and 300 times greater than any other autumn in the previous 20 years, according to research by marine scientist Amy Siuda and colleagues at the Sea Education Association, Woods Hole in Massachusetts.
While the exact causes for the boom have yet to be pinned down, Wang’s team believes that a number of environmental factors are contributing to the sargassum explosion. Among them are abnormal ocean currents and wind patterns linked to climate change.
The destruction of the Amazon rainforest is also thought to have fueled the growth of sargassum. As huge swathes of the rainforest are cut down, it is replaced with heavily fertilised farmland. The fertiliser ends up in the Amazon river and eventually in the Atlantic where it floods the ocean with nutrients such as nitrogen. Records show during the large 2018 bloom there were higher levels of nutrients in the central Atlantic region where the sargassum grows compared with 2010, says Wang.
When scattered across open water, sargassum — sometimes known as the “floating golden rainforest” — serves as an important breeding ground for turtle hatchlings and a refuge for hundreds of fish species. The problem comes when sargassum washes up on the beach and starts to rot, emitting hydrogen sulfide — a gas that smells like rotten eggs. “It is a good vegetation in the ocean, on the beach it turns into something bad,” says Wang.
In open water, sargassum provides a crucial habitat for fish and other marine animals — but on shore it can make it harder for turtles to spawn and hatch (Credit: Getty Images)
In open water, sargassum provides a crucial habitat for fish and other marine animals — but on shore it can make it harder for turtles to spawn and hatch (Credit: Getty Images)
The pungent smell and unsightly appearance are driving tourists away from beach resorts in the Caribbean and Mexico’s Yucatan peninsula — a blow to the region’s economy, which relies heavily on tourism. In 2018, Laura Beristain Navarrete, mayor of coastal town Playa del Carmen in Mexico, told a local newspaper that tourist numbers in the region had fallen by up to 35% due to sargassum.
Removing the seaweed from the beaches is a costly and time-consuming process. In 2019, Mexico’s president, Andrés Manuel López Obrador, estimated that clearing all the sargassum that year would cost $2.7m (£2m) and enlisted the country’s navy to help with the massive clean-up.
Besides its catastrophic impact on tourism, sargassum is also a public health concern, says Wang. When it decays, it attracts insects that can cause skin irritation, while hydrogen sulphide exposure from rotting sargassum has been linked to neurological, digestive and respiratory symptoms.
The stranded seaweed poses a serious threat to marine wildlife too. The huge piles of seaweed prevent turtles from nesting and ensnare dolphins and fish in the coral reefs. “Sargassum can suffocate coral reefs by covering them and decimate breeding grounds for turtles,” says Mike Allen, a marine scientist from the University of Exeter who has developed a cheap way of converting sargassum into biofuels and sustainable fertiliser.
Allen and a team of researchers from the universities of Exeter and Bath devised a process called hydrothermal liquefaction (HTL), which uses high pressure and temperature to split wet biomass into four components: a bio oil that can be upgraded to biodiesel, water-soluble organic compounds used to produce fertiliser, carbon dioxide (which the researchers say they aim to capture rather than release into the atmosphere) and char, a solid material containing all the metals found in the seaweed, which the team also plans to recover at a later stage.
“I liken it to ‘geology in a tin’,” says Allen. “Because the pressures and temperatures are so high, we can put pretty much anything in there. We can convert plastic alongside the [sargassum] biomass in the same process,” he says. Nylon fishing nets tangled in the coral reefs are also turned into fertiliser.
Researchers believe the growing sargassum blooms are down to a combination of changing ocean and wind currents, and the deforestation of the Amazon (Credit: Getty Images)
Researchers believe the growing sargassum blooms are down to a combination of changing ocean and wind currents, and the deforestation of the Amazon (Credit: Getty Images)
There are some drawbacks, though. The process is energy-intensive and runs on fossil fuels, says Allen, though heat from the process can be recovered and reused to improve efficiency.
The project is still in the research phase and the researchers have converted 100kg (220lb) of sargassum to date but Allen hopes to scale it up and partner with companies and governments to tackle the issue. The aim is to find a solution to the sargassum problem that is economically viable and supports the local community. “What we are trying to do is make the clean-up of contaminated areas profitable, so that there is an incentive to do it, improve quality of life and protect the environment,” says Allen.
In parts of Mexico and the Caribbean, locals are taking the matter into their own hands and finding innovative ways to turn the environmental disaster on their coastlines into a sustainable economic opportunity. Some are turning sargassum into materials from paper to building materials. In Playa del Carmen, for example — one of Mexico’s most popular tourist destinations — a community group is tackling the sargassum invasion by turning it into soap.
The Biomaya Initiative, an organisation established to deal with the sargassum glut, hires local residents to collect the foul-smelling seaweed from the beaches, and then cleans it to remove metals and plastics. Then women living in nearby villages, that date back to the Maya period, mix the processed sargassum with glycerin and honey to make soap which they sell for $2 (£1.50) a bar to hotels, hospitals and shops in the area.
“As a community we decided to do this to protect the planet and take care of our beaches,” says Gonzalo Balderas, founder of Biomaya Initiative. In the past three years, tourist numbers have plummeted due to sargassum in Playa del Carmen, Balderas says. “It’s supposed to be a dream beach.”
Entrepreneurs are finding an increasing number of ways to turn the sargassum glut into something useful — such as paper (Credit: Getty Images)
Entrepreneurs are finding an increasing number of ways to turn the sargassum glut into something useful — such as paper (Credit: Getty Images)
While in St Catherine’s, a coastal community in south-east Jamaica, Daveian Morrison is using sargassum to produce animal feed. Morrison founded Awganic Inputs in 2018 after receiving reports of sargassum piled 15ft (4.6m) high on the beaches. “It affects local tourism and leisure activities and suffocates fish and turtle hatchlings,” says Morrison. “I figured it is time for action.”
Morrison wanted to solve two major problems in Jamaica: sargassum and the lack of affordable fodder for goats, a local delicacy. The country currently imports $15m (£11.3m) of mutton and goat meat each year. “Our goats look very lean as they do not consume enough minerals. Sargassum has many nutrients, minerals and salt,” he says.
Awganic Inputs buys sargassum from local collectors and dries, cleans and shreds the seaweed while it is still fairly fresh, before mixing it with crop biproduct to produce fodder for goats. For the more rotten sargassum, it is turned into charcoal and sold for use in cosmetics.
Awganic Inputs recently carried out a pilot project, converting 544kg (1,200lb) of sargassum into goat feed and selling it to farmers for $0.26 (20p) a kilogram. The response was very positive, Morrison says. While the coronavirus pandemic has stalled production for now, Morrison hopes to scale up and start selling cheap sargassum feed across Jamaica next year. “Many people see sargassum as a nuisance,” he says. “They are glad that something is happening with it.”
Such efforts to tackle the sargassum glut are undoubtedly small compared to the overwhelming mounds decomposing on Atlantic beaches. Goat feed, soap and biofuels won’t make much of a dent in these heaps any time soon, but they are a sign of coastal resilience — and of local economies adapting to turn a rotten mess into something of use, whatever the changing oceans wash up.
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