Giant wind farms
Wind turbines of the Block Island Wind Farm, so far the only offshore wind project in operation in the U.S.
Credit: Don Emmert/AFP via Getty Images
On Monday, President Biden designated a 'Wind Energy Area' in the waters between Long Island and New Jersey. It's part of an ambitious plan to build giant wind farms along the East Coast. There's currently only one offshore wind farm in the Eastern U.S., off Rhode Island (1).
When those wind farms get built, you can bet there'll be Danish companies involved. In 1991, Denmark built Vindeby, the world's first offshore wind farm. In the years since, Danish companies have maintained their global lead.
In February, the Danish government announced it would build the world's first 'Energy Island'. Everybody else in the world, take note: if the Danes pull this off, similar islands could soon pop up off your shores – perhaps also in the New York Bight.
So, what's an Energy Island, and why does Denmark want one? For the answer, we spool back to June 2020, when a broad coalition of Danish parties, left and right, in government and opposition, concluded a Climate Agreement. This is Denmark's plan not only to make a radical break with fossil fuels but also to show the rest of the world how it's done.
On the rise again
Close-up of Energy Island, with two of the seawalls at the back and the port at the front.
Credit: Danish Energy Agency
Due in large part to its pioneering work with wind energy, Denmark has a green image. But that hasn't always reflected reality. Yes, in 2019 the country generated 30 percent of its energy from renewable sources – earning it 9th place worldwide (2). But in 2018, Denmark also was the EU's leading oil producer (3).
Under the Climate Agreement, that will stop. Denmark will no longer explore and develop new oil and gas fields in its section of the North Sea. Extraction will be gradually reduced to zero. In exchange, Denmark will dramatically scale up the production of sustainable energy via offshore wind farms. The ultimate goal: nationwide carbon neutrality by 2050.
Offshore wind farms produce the bulk of Europe's sustainable energy. And after a dip in the first decade of the century, offshore wind farms are on the rise again (4). One reason for the increased popularity: taller turbines, which means larger blades, which means greater capacity.
- In 2016, the tallest turbines were 540 ft (164 m) and had a capacity of 8 megawatts (MW).
- In 2021, turbines can be up to 720 ft (220 m) tall, generating up to 12 MW.
- Soon, the turbines will reach 820 ft (250 m) – not that much shorter than the Eiffel Tower (1,030 ft or 314 m, street to flagpole). These will have a capacity of up to 20 MW.
Centralised management
Potential position of Energy Island (red) off the western coast of Jutland, surrounded by a wind farm (green) filled with turbines (blue dots).
Credit: Danish Energy Agency
As the shallow parts of the North Sea (<66 ft; <20 m) fill up with wind farms, the issue of managing the energy flow produced by these farms becomes acute. The obvious solution would be to build a central point where the energy is collected, converted from AC to DC and transmitted to one or more points onshore. Centralised management of the wind farms would mitigate the fluctuations in energy production and make it easier for supply to meet demand.
If supply is greater than demand, these collection points can also serve as storage units. Excess energy could be stored in batteries or transformed into hydrogen via electrolysis. If and when necessary, the hydrogen can then be transported onto land and reconverted into electricity.
The Dutch are thinking about it, and some have suggested the Dogger Bank as an ideal location: shallow and central within the North Sea, ideally placed to distribute energy to the various countries bordering the sea. But the Danes are doing it. The Climate Agreement envisaged not one, but two energy islands.
One would be Bornholm, Denmark's Baltic island, halfway between Sweden and Poland, which would serve as the hub for local offshore wind farms. But the other would be an entirely new, entirely artificial island in the North Sea, to be built about 50 miles (80 km) off Thorsminde, on the western coast of Jutland.
10 million households
Schematic overview of how an Energy Island could serve as a hub for collecting and redistributing sustainable energy.
Credit: Danish Energy Agency
In February, the Danish government revealed how much this Energi-Ø would cost, how long it would take to build – and what it might look like.
- Energy Island will be built via the caisson method – essentially, sinking a watertight box to the bottom of the sea. The island will be protected from storms by high seawalls on three sides. The fourth side will feature a dock for ships.
- Construction could start in 2026 and is expected to take three years. Building the wind farms and transmission network will take a few years more. By 2033, it could be churning out its sustainable GWs.
- In its initial phase, the island will have an area of about 12 hectares (30 acres, or about 18 soccer fields). It will centralize the production of about 200 offshore wind turbines, with a joint capacity of 3 GW. That's about the equivalent of 3 million households – slightly more than the total for Denmark.
- When fully completed, the island will have an area of around 46 hectares (114 acres, just under 70 soccer fields), collect the energy of 600 turbines, for a total capacity of 10 GW (5). That covers 10 million households.
- 10 GW is equivalent to about 150 percent of Denmark's entire electricity needs (households, industry, infrastructure, etc.) That leaves plenty of scope for supplying neighbouring countries. Agreements have already been reached with Germany, the Netherlands and Belgium.
The plan also foresees a plant for hydrogen production on the island, either to be piped onshore, or stored and transported in large batteries.
Yet untested aspects
Location of Energy Island (yellow) in the North Sea, showing potential connections towards neighboring countries.
Credit: Danish Climate Ministry / Vimeo
In all, the island would cost DKK 210 billion (US$33 billion) to build – by far Denmark's largest construction project (6).
The project will be undertaken in a public-private partnership between the Danish state and commercial interests. Because it is 'critical infrastructure', the state will retain a stake of at least 50.1 percent in the project. There are two scenarios for co-ownership:
- The island will be owned in its entirety by a company, in which the Danish state retains at least that smallest of majorities;
- Private companies will be able to own up to 49.9 percent of the island itself.
The Danish government needs private-sector input to overcome unknown and as yet untested aspects of the project, not just in terms of design and building an entire island from scratch, but also on how to operate and maintain it, and even when it comes to financing and risk management.
But where there's risk, there is potential. If the project is successful, it will become the blueprint for similar energy islands the world over – and the companies that helped build the first one, will be in high demand to build the other ones too, perhaps soon in Biden's 'Wind Energy Area'.
Green, as the Danes have discovered, is not just the color of nature. It's also the color of money.
Strange Maps #1077
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(1) Coastal Virginia Offshore Wind, a two-turbine pilot project 23 miles (43 km) off Virginia Beach, was completed last year.
(2) The Top 10 (2019) are Iceland (79%), Norway (66%), Brazil (45%), Sweden (42%), New Zealand (35%), Austria (38%), Switzerland (31%), Ecuador (30%), Denmark (30%) and Canada (28%).
(3) With 5.8 megatons of oil equivalent (Mtoe), Denmark beat Italy (4.7 Mtoe) and Romania (3.4 Mtoe). Oil production in the EU is on the way down. It peaked in 2004 (42.5 Mtoe) and has since halved (to 21.4 Mtoe in 2018). A similar trend has occurred in the two key non-EU oil producers in Europe. a. Norway's oil production peaked in 2001 (159.2 Mtoe) and has since more than halved (to 74.5 Mtoe in 2018). b. The UK's oil production peaked in 1999 (133.3 Mtoe) and has since been reduced by almost two thirds (to 49.3 Mtoe in 2018).
(4) The Global Wind Energy Council estimates that in 2020, a record 82.3 gigawatt (GW) of new wind power capacity was added, a 36% increase over 2019.
(5) The Bornholm energy hub is projected to top out at 2 GW.
(6) Inaugurated in 2000, the famous Øresund Bridge (Øresundsbroen), connecting Sweden to Denmark, cost about DKK 25 billion (US$4 billion) in today's money. When it's finished (by 2029, if work continues apace), the Fehmarn Belt Fixed Link (18 km) between the Danish island of Lolland and the German island of Fehmarn, will be the world's longest road/rail tunnel. It will have cost about DKK 55 billion (US$ 8.7 billion).
It's something experts are still piecing together, but there's a growing body of evidence that as humans left Africa and scattered across the globe, they often did so by traversing land bridges that are now underwater, and, in other cases, by crossing oceans.
There was really no other way they might have gotten to Australia, for example, even linked as it was for a time with New Guinea as the Sahul landmass. There was always ocean between the continent and Asia, from which its early inhabitants apparently came. It may well have been a less daunting passage at times of lower sea levels, however.
What, if anything, guided ancient mariners to the places they reached remains an intriguing riddle. Did they just drift on currents hoping to bump into somewhere to land, or was their navigation more intentional?
A new study from researchers at the University of Tokyo suggests the latter, at least in the case of the ancient migration from Taiwan to the Ryukyu Islands in southwestern Japan—Okinawa is one of the those islands—some 30,000 to 35,000 years ago.
The study is published in the journal Scientific Reports.
Not an easy trip
Yosuke Kaifu of the University Museum at the University of Tokyo and his colleagues sought to answer the longstanding riddle. "There have been many studies on Paleolithic migrations to Australia and its neighboring landmasses," said Kaifu in a press release, "often discussing whether these journeys were accidental or intentional."
"Our study looks specifically at the migration to the Ryukyu Islands because it is not just historically significant, but is also very difficult to get there."
The ancient sailors would have known of the islands because they were visible from the top of a mountain on the coast of Taiwan, although not down along the coast itself.
The waters between Taiwan and the Ryukyu Islands represented an opportunity for the researchers since they are dominated by the Kuirishio current, one of the strongest currents in the world. The researchers' hypothesis was that sailors were unlikely to have crossed it accidentally. Says Kaifu, "If they crossed this sea deliberately, it must have been a bold act of exploration."
Okinawa shoreline
Credit: w.aoki/Adobe Stock
Buoys will be buoys
Kaifu had long been interested in devising some kind of experiment to better understand those who made the journey but, "had no idea how to demonstrate the intentionality of the sea crossings." Upon meeting the study's Taiwanese co-authors, experts in the Kuirishio, the outlines of a plan because clear.
To test the possibility of an accidental arrival at the Ryukyu Islands, Kaifu and his team set 138 satellite-tracked buoys adrift and tracked how many of them managed to float over to the islands.
"Only four of the buoys came within 20 kilometers of any of the Ryukyu Islands, and all of these were due to adverse weather conditions," explains Kaifu. This was an unlikely factor in the human travelers' voyage because, "If you were an ancient mariner, it's very unlikely you would have set out on any kind of journey with such a storm on the horizon."
The results reveal that the current was more likely to take ancient sailors anywhere but the islands. "What this tells us is that the Kuroshio directs drifters away from, rather than towards, the Ryukyu Islands; in other words, that region must have been actively navigated."
Where the buoys traveled
Credit: Tien-Hsia Kuo/University of Tokyo
An old current
Supporting the researchers findings are geologic records from the area that suggests the Kuirishio hasn't changed since the mariners' journey so long ago — it's been present in its current form for about 100,000 years.
The research appears to answer the riddle of at least this one ancient migration, says Kaifu: "Now, our results suggest the drift hypothesis for Paleolithic migration in this region is almost impossible. I believe we succeeded in making a strong argument that the ancient populations in question were not passengers of chance, but explorers."
By now, you've probably worked out your personal go-to strategy for those times when you discover — a little bit too late — that you've eaten too much. Maybe you're the proactive type, arriving at the table in sweatpants. Otherwise, maybe a quick postprandial nap or a loosened belt is your thing. A new paper published in the journal Nature Communications describes the unique way that starlet sea anemones deal with extra food: They simply grow a pair of new tentacles, as if to make room.
Starlet sea anemone basics
Credit: Smithsonian Environmental Research Center/Flickr
The starlet sea anemone, or Nematostella vectensis, lives burrowed into the mud and silt of coastal salt marshes. Research suggests it's originally native to the east coast of North America, although it can also be found along the continent's west coast, around Nova Scotia, and in U.K. coastal marshes.
Being stationary creatures, starlet sea anemones have to reach out and grab nutrition floating by. Their natural diet is mainly copepods and midge larvae, though they're also perfectly happy eating brine shrimp in a laboratory setting. The anemones grab food with their tentacles whose cilia then wiggle the meal down to their mouths.
In the larval stage, the anemones have a quartet of tentacles, though they may develop up to 24 of them. A more typical amount is 16.
While the starlet sea anemone may grow larger in a lab setting, in the wild its clear, worm-like body typically extends from 10 to 19 millimeters (about three quarters of an inch) in length. Tentacles may add another 8 mm.
Members of the phylum to which the starlet sea anemone belongs, the Cnidaria phylum, have the unique ability to grow new body parts throughout their lives in response to environmental influences. Among these influences are fluctuations in the amount of available food. Nonetheless, no other animal has yet been seen growing new appendages when they get extra sustenance.
The study
Tentacles budding, or not, under different feeding conditions
Credit: Ikmi, et al./Nature Briefing
Observations of starlet sea anemones in his lab prompted lead author of the paper, Aissam Ikmi of the European Molecular Biology Lab Heidelberg, to undertake the new research. He'd noticed what seemed to be an association between the amount of brine shrimp being consumed and the sprouting of new tentacles.
Ikmi and his team raised over 1,100 starlet sea anemone polyps to which they fed brine shrimp. Some of them began with 4 tentacles while the rest already had 16.
For over six months, the researchers varied the animals' food supply at cyclical intervals, feeding the anemones for a few days and then stopping for a few days.
The scientists tracked tentacle growth throughout the experiment, creating a spatio-temporal map that identified periods of tentacle growth in relation to feeding cycles.
They found that the anemones grew new tentacle pairs during feeding periods, and new tentacle production did indeed stop when their food supply was temporarily cut off. Tentacle-pair budding occurred at the same time as an anemone also doubled its body size.
"When food was available, however, primary polyps grew and sequentially initiated new tentacles in a nutrient-dependent manner, arresting at specific tentacle stages in response to food depletion." — Ikmi, et al.
Two ways to bud
In this illustration from the paper, development from 4 to 12 tentacles is characterized by trans budding. Cis budding is present beginning with 16 tentacles.
Credit: Ikmi, et al./Nature Briefing
The team identified two budding modalities, they named "cis" and "trans." In both modes, pairs of tentacles were produced, budding either simultaneously or consecutively. In:
- Trans budding — the two new tentacles budded on opposite sides of the anemone.
- Cis budding — the two new tentacles budded from within the same segment.
Natural selection takes time. According to the fossil record, sharks, for example, have been essentially the same for hundreds of millions of years. But something's up lately, and by "lately" we mean the last nine million years. Sharks off of Australia have learned to walk. Not Great Whites, fortunately. Small sharks that feed on coral reefs. Cute sharks, actually.
Scientists have known for some time that five such shark species exist, but new research nearly doubles that number to nine. The new information comes from a 12-year study from an an international team of scientists from University of Queensland (UQ), Conservation International, CSIRO, the Florida Museum of Natural History, and the Indonesian Institute of Sciences and Indonesian Ministry of Marine Affairs and Fisheries published in Marine and Freshwater Research.
Don't mess with success
Over the last 400 million years, only about 1,200 shark species have emerged. "We see animals from 180 million years ago with exactly the same teeth," Gavin Naylor of the Florida Program for Shark Research at the University of Florida tells National Geographic. While it's true they're not the most prolific reproducers, and have a long life span, that's still plenty of time for useful mutations to arise. On the other hand, if it ain't broke, don't fix it — Earth and the oceans may change, but as predators, sharks do just fine as they are. Even if, as Naylor says of sixgill sharks, they "seem stuck back in time."
Walking to dinner
The walking sharks, or "epaulette sharks," live in coastal waters off northern Australia and the island of New Guinea. They prowl coral reefs when the tide goes out, walking through shallow water on their pectoral fins in the front and pelvic fins in the back, on the hunt for crabs, shrimp, small fish. They're adept at wriggling their way into tight nooks to find food, too. "At less than a meter long on average," says Christine Dudgeon of UQ, "walking sharks present no threat to people, but their ability to withstand low oxygen environments and walk on their fins gives them a remarkable edge over their prey of small crustaceans and mollusks." Says Dudgeon, "During low tides, they became the top predator on the reef."
The abilities of the small sharks — they're less than three feet in length — definitely put them in a class of their own, says Dudgeon: "These unique features are not shared with their closest relatives the bamboo sharks or more distant relatives in the carpet shark order including wobbegongs and whale sharks."
Though the five epaulette species don't look much alike, varying in markings and color, their DNA identified them as family. Says Dudgeon, "We estimated the connection between the species based on comparisons between their mitochondrial DNA which is passed down through the maternal lineage. This DNA codes for the mitochondria which are the parts of cells that transform oxygen and nutrients from food into energy for cells."
What's the hurry?
The researchers theorize that a few factors may have accelerated the epaulets' evolution. First off, they keep to themselves in their own separate region, with extensive inbreeding perhaps speeding up the rate of mutation. "Data suggests the new species evolved after the sharks moved away from their original population, became genetically isolated in new areas and developed into new species," explains Dudgeon. "They may have moved by swimming or walking on their fins, but it's also possible they 'hitched' a ride on reefs moving westward across the top of New Guinea, about two million years ago."
Another possible factor are the ever-changing reefs themselves. They're continually in flux as oceans change and as corals live and die, with rising and falling sea levels, as well as changing currents and temperatures. The epaulettes' success depends on adapting quickly to a very dynamic environment, about which Naylor says, "It's the shark equivalent of the Galápagos, where you can see shark evolution in action."
Beachgoers needn't fear for their tootsies just yet, but just wait another few million years, and who knows?
