Grinding Wheat, Powering Homes
If 0.1 percent of the renewable energy available within the oceans could be converted into electricity it would satisfy the present world demand for energy more than five times over.
—UK Marine Foresight Panel
When Ferdinand Magellan set sail from Spain in the summer of 1519, he was looking for “the Dragon’s Tail,” a passage rumored to cut across the southern tip of South America, connecting the Atlantic with the Pacific. Fourteen months later, he was elated to find the passage, but his ships were ill prepared for the violent weather and wild tidal currents of the three-hundred-mile labyrinth that now bears his name. The worst of it was concentrated in an hourglass channel, known today as First Narrows, just inside the Atlantic entrance. With twenty-foot tides and ten-knot currents pouring from the straits, his ships, powered only by wind, were overwhelmed. Although his accomplished Portuguese and Spanish crews were familiar with tides, these were six times larger—and the currents exponentially fiercer—than anything they’d encountered at home. On a typical day, even with a fresh breeze, his ships would make no more than seven knots. Against a ten-knot current, they’d be sailing backward.
In the sixteenth century—the early years of the Age of Discovery—the European map of South America ended just south of Buenos Aires. Beyond, there was nothing—in fact, worse than nothing: the world was still considered flat by many, so ships sailing south on the ocean-sea, as the Atlantic was called, were embarking not just on uncharted, monster-infested waters but quite possibly on a course that would lead them off the world’s edge. No European ship had ever returned from a journey beyond Buenos Aires. Yet Magellan’s ambition was to sail through the fabled Dragon’s Tail to the Spice Islands in the western Pacific, returning to Spain laden with cloves, nutmeg, cinnamon, and other riches. He was ruthless in this endeavor, often beating his crew or withholding food and water as a means of punishment.
By the time Magellan sighted the narrow opening between present-day Patagonia and Tierra del Fuego, he and his crew had survived months of storms, an attempted mutiny, and the loss of one of his five ships. Antonio Pigafetta, the fleet’s chronicler and one of the few to survive the expedition, wrote: “After going and setting course . . . toward the said Antarctic Pole . . . we found by miracle a strait which we called the Cape of the Eleven Thousand Virgins.”
Magellan’s crew struggled into the Dragon’s Tail but were spit out by the current. They had to wait out the ebb tide at anchor and sail with the flood, which pushed them into the straits. This sounds simple enough, but the passage was entirely uncharted, so every move was a risk. Secure anchorages were difficult to find, as the ebb’s relentless pull led to one dragging anchor after another.
Inside the straits, weary crew members were fooled by channels dead-ending in the mountains and befuddled by high and low tides that matched no pattern they had seen before or could understand. And for good reason: they were at the very point where two large oceans meet—two oceans whose tidal periods don’t match. The Pacific tide usually crests a few hours ahead of the Atlantic, which creates a confusing seesaw effect in the straits. This was nothing like the relatively predictable tidal patterns on the coast of Spain. Exhausted and homesick, Magellan’s crew members could only guess what they were up against. For all they knew, the water’s turbulence was a sign that they were indeed about to be sucked over the edge of the world.
It took Magellan six weeks to find the “small gulf on the other side”—the planet’s largest ocean—which he named the Pacific. As he sailed toward the Spice Islands in search of the exotic cargo that he hoped would bring him fabulous wealth, he could not have guessed that the tidal power that vexed his voyage through the Dragon’s Tail would one day not only be understood and charted but harnessed as a source of heat and light.
East of the Andes, where I am, the terrain drops precipitously from enormous mountains to long stretches of semi-arid steppe. This bronze-colored scrubland with an occasional wind-twisted tree is traveled by long, straight gravel roads that wilt in distant mirage. Tierra del Fuego, “Land of Fire,” was christened by Magellan when he saw smoke drifting from the fires of Fuegian Indians—the Ona, Haush, Yaghan, and Alacaluf—who had been living there for thousands of years. When Charles Darwin sailed through here on the Beagle in 1836, three hundred years after Magellan, he wrote, “No one can stand unmoved in these solitudes, without feeling that there is more in man than the mere breath of his body.”
As I rest my forearms on the cap rail of the Patagonia, the ferry that today shuttles across First Narrows, I gaze on a scene almost unchanged since Magellan’s voyage. The spit he christened Cape of the Eleven Thousand Virgins lies about twenty miles east, since renamed Cape Dungeness. To the west, the straits widen, then pinch again at Second Narrows before opening into a large basin near the town of Punta Arenas, Chile. Farther west, the chiseled faces of the Andes loom above the Pacific. There, rainfall is heavy and tidewater glaciers shift and moan, calving apartment-building-sized chunks of ice into the sea. Williwaws, frigid air that builds and releases suddenly from mountaintops, rush down valleys at more than 110 miles per hour, shaking trees and tearing at the water’s surface. Frequent fog, heavy seas, and treacherous currents can make boat travel impossible through the fjords that stretch 1,200 miles up the Chilean coast.
On a clear and windless April day—the southern hemisphere’s fall—I stand on the ferry’s deck and hear the murmur of tidal currents plying the pebbled shore and erupting in boils that surge from below. Cormorants and penguins dive for fish. “I like to watch the way animals use tidal currents,” says Gareth Davies, who leans his thick arms on the rail beside me. As founder and director of Aquatera, a consulting company based in the Orkney Islands of northern Scotland, Davies travels the world helping communities, corporations, and governments understand marine energy. We are both here for a tide and wave energy workshop in Punta Arenas, sponsored by Aquatera, Chile’s Ministry of Energy, and Alakaluf, an organization run by a local oceanographer, Sergio Andrade. But for the moment it is just Davies and me, watching the tide.
“These places draw us toward them,” Davies says, his large brown eyes studying the surface. “They’re dangerous, but their power and vibrancy are mesmerizing.”
“I see them as metaphors of change,” I tell him. “As one tide is born, another is dying. It’s in these choked narrows that we witness the immense influence of the moon.”
“I like that,” Davies says. “Since the moon drives tide energy, maybe we should be calling it ‘moon energy’!”
A year earlier I had knocked on Davies’s office door in Stromness, a small Orkney port town with narrow cobbled streets and tall stone buildings. I was there visiting the European Marine Energy Center (EMEC), the world’s largest tide and wave energy test site, established in 2003. Davies, a heavyset PhD marine biologist in his early fifties, moved to the Orkney Islands in 2000 to help set up EMEC. His consulting company, Aquatera, is independent of EMEC but housed in the same building. Serendipitously, he was in his office when I knocked, having just returned from Paris and on his way to Japan to consult about potential tide energy in Naruto Straits.
We found a park bench overlooking Hoy Sound and the entrance to Scapa Flow, location of one of the test sites. The Orkney Islands were selected as Scotland’s premier test site because of the fast currents, which are created in much the same way as the currents in the Straits of Magellan—in this case, the uneasy meeting of the North Sea and the Atlantic. As one body rises, water flows through the seventy Orkney Islands and skerries (rocky islets) to fill the neighboring ocean, bringing to life hundreds of high-energy passages. To the south, on the other side of Hoy, the infamous Pentland Firth separates the Orkney Islands from mainland Scotland. In that nine-mile-wide channel, the tide runs at ten to twelve knots, and sites are already leased for the long-term home of machines that pass testing.
“Most oceanographers agree that there are about 3.5 terawatts of raw power in the ocean’s tides,” said Davies. “That’s equivalent—at any given moment—to about 3,500 large coal plants running at capacity.” During my visit to the Orkney Islands, I learned that technological and environmental limitations make only a quarter of that raw tide energy harvestable. On a global scale, that probably isn’t quite the silver bullet to end fossil fuel addiction, but it might be enough to play a meaningful role with other renewables, such as wind and solar. For communities and smaller countries surrounded by water, it could be transformative.
Ten months later, Davies invited me to join him at Chile’s first international marine energy workshop. It was to be a gathering of experts from Chile, Norway, Scotland, Canada, and the United States to discuss Chile’s future in tide and wave energy. Having read about Chile’s commitment to explore tide energy, I instantly agreed; later I met Davies and his assistant, Tom Wills, in Santiago so we could drive down the coast together to the workshop.
As Davies and I study the water’s churned and dimpled surface from our perch on the First Narrows ferry, he tells me of Scotland’s marine energy history and the lessons it might offer Chile. In 1982 the Scottish government issued a mandate to generate 100 percent of its electricity with renewable resources by 2020—by far the world’s most ambitious renewable energy target. For comparison, the European Union aims for 20 percent by 2020, and Germany, with some of the world’s most aggressive renewable standards, aims for 30 percent by 2020 and 80 percent by 2050. Chile’s goal is 10 percent by 2024. The United States has no federal standard.
The Orkney Islands were chosen as the Scottish center for renewables because of the exceptional wind, wave, and tidal resources as well as its active marine industry. EMEC was set up (largely with European Union and also some Scottish government funds) to offer test sites for international developers. To kick-start the testing process, the government initiated in 2010 the Saltire Prize, a £10 million purse for the first device to generate 100 gigawatt hours “using only the power of the sea” for a continuous two-year period. Since 2003, EMEC has overseen the testing of more than ten different tide machines, most of them turbines that look and function like underwater windmills. To date, none of them has come close to winning the Saltire Prize.
“Scotland certainly doesn’t have all the answers,” says Davies, “but we’ve been at it longer than anyone else. Chile’s on the other end of the spectrum—just beginning. They have great marine resources. And right now they have the advantage of studying what’s happening in other countries and choosing their own path into this arena.”
When it comes to renewable energy, Chile’s noodlelike shape may be one of its best assets. Squeezed between the Pacific and the Andes, the country stretches through sixty degrees of latitude, capturing almost every kind of terrain and bioregion, from deserts to rainforests, mountains to conifer forests, beaches to rocky shorelines. The 41,000-square-mile Atacama Desert in the far north competes for the best solar potential anywhere on the planet. Chile’s 4,000 miles of Pacific coastline facing due west, battered by wind and swell from southern hemisphere storms, has almost limitless offshore wind and wave energy potential. So it is with geothermal energy too: balancing atop the Pacific Ring of Fire, this country is rocked by an average of one and a half earthquakes a year, magnitude five or larger. And the tides and sinewy fjords of southern Chile create thousands of miles of high-energy tidal passages.
“Harnessing even a fraction of the country’s renewable energy could easily meet all of Chile’s electricity needs, and more,” says Davies as we leave the First Narrows ferry and head toward Punta Arenas.
On the morning of the workshop, the convivial chatter of sixty people hushes as Don Carlos Barria from the Chilean Ministry of Energy begins:
Bienvenidos a todos. Gracias por venir desde largas distancias para estar aquí para ayudar a Chile navegar su camino en el ámbito de la energía marina. Estamos entusiasmados por las discusiones que tendrán lugar en los próximos dos días.
“Welcome, everyone,” he says. “Thank you for coming from so far away to help Chile navigate its way in the marine energy field. We’re excited about the discussions that will take place in the next two days.” The Chilean government, he explains, recognizes its renewable resources and is developing a national energy strategy that looks to the year 2030. He points out that although Chile is one of the richest countries in South America, it’s among the poorest when it comes to energy, importing at great expense more than 75 percent of its fuel in the form of natural gas, coal, and oil. “We need to develop local renewable energy for many reasons,” he says, “but it’s not as simple as just buying and installing the right equipment. We must also rewrite our laws and create new supporting infrastructure.”
From a window seat in the hotel conference room, I can see the deep blue-green of the straits and the distant snowy mountains of Tierra del Fuego. My mind wanders back to Magellan, who cleverly found a way to use the tide and wind to claw through the straits. An expedition like his—the first to circumnavigate and prove the world was round like an apple, not flat like a table—was fueled entirely by wind and will. But the wind that filled his sails hundreds of years ago pushed more than ships. It was also driving thousands of mills across Europe and Asia, as it had been for centuries. As early as the tenth century, windmills were used in Persia to pump water for irrigation and in Europe to grind corn. The technology reached a peak in the Netherlands between 1500 and 1650, where windmills were put to use draining agricultural fields and grinding wheat, spices, and fiber to make cloth.
The tide energy that cursed Magellan’s navigation of the Dragon’s Tail in 1520 had already been recognized as a blessing in other parts of the world. Historians believe the first tide mill may have appeared in Roman times (200–400 CE). Confirmed evidence of a mill built on Strangford Lough in northern Ireland dates back to the late eighth century. By the seventeenth century, the simple elegance of tide mill technology had reached a tipping point, and more than a thousand were operating on the coasts of the United Kingdom, the Netherlands, Portugal, Belgium, France, and Spain. The Tagus estuary in Portugal, south of Lisbon, had as many as forty during this period. Like windmills, they were put to work milling cereals, but also stamping copper, crushing or rolling kaolin (clay) and tree bark, pumping brine for extracting salt, preparing pulp for paper, crushing ice, and sawing wood. It’s not unlikely that a tide mill on the south coast of Spain provided the flour used by Magellan to make hardtack, a twice-cooked brittle biscuit that was the expedition’s main food supply.
Tide mill engineering was straightforward. A house with a wooden paddlewheel was built across the tidal estuary. As the tide rose, gates were opened to fill a holding pond, or millpond, on the upland side. When the tide peaked, the gates were closed, trapping the water. The gates stayed closed as the tide in the estuary dropped, creating a difference in water level (a hydraulic head). When the tide on the seaward side had dropped sufficiently—in this case three or four feet—a jet of water was released from the millpond through a chute, or sluice gate, aimed at the waterwheel’s wooden paddles. The wheel would rotate, never very fast, driving gears with iron or wooden cogs, which would eventually turn the grinding stones. On a large tide, the wheel would run five or six hours.
This technology was introduced to North America’s eastern seaboard in the early seventeenth century and quickly spread from Boston to the Bay of Fundy. The first tide mill on record was built in Port Royal, Nova Scotia, in 1607. A hundred or more were operating in the late eighteenth century. These mills were located in estuaries with large tides and convenient access for oceangoing ships, enabling the import of raw materials and the export of mill-processed goods, including lumber and cloth.
The workings of a tide mill.
Tide mill communities flourished in Europe and North America. Millers worked on the tide’s schedule, an hour later each day and peaking during the new and full moon. When the heavy tide gates closed with a resounding clunk, whether night or day, all the community knew it was high tide and the millpond was full: it was time to get ready for work. The waterwheel would start turning in a few hours.
In 2013 I took a two-hour train ride from London to see the Eling Tide Mill, which has straddled the mouth of the Bartley River near Southampton for 230 years. From the train station, a cabdriver shuttled me through progressively smaller villages and narrower streets until he stopped in front of an unassuming red-brick building. I stood on the street for a few minutes after the cab left, taking in the building and the estuary beyond. The tide was on its way up, slipping under fifty or more boats crowded into the anchorage. Many were still aground and listing in the mud, their masts leaning every which way. I imagined sailing ships laden with raw corn and wheat standing off the estuary during the mill’s heyday in the eighteenth and nineteenth centuries, waiting for enough water to float them in. At high slack, they would have sailed in, tied off to the mill just long enough to exchange raw goods for flour and set sail again before getting caught by the falling tide. Raw goods were also brought from inland by horse and carriage across the one-lane bridge that still connects the mill with the rest of Eling.
The mill itself has three floors and a steeply pitched slate roof. It was built in 1785, but there’s evidence that the site may have supported two corn mills, one of them fueled by the tide, as early as 1086. The present building, damaged and restored several times, is now under the care of the town council, which manages a museum in the old miller’s quarters as well as the operation of the mill itself, which today produces a monthly average of 1,700 pounds of whole-meal brown and strong white flour. Some of this is baked into breads and cookies sold in the museum gift shop, and the balance is sold to local bakeries. The three-pound bags for sale at the museum boast “Canute 100% Stoneground: Milled from English bread-making grain for a fuller flavour at the only working tide mill in the United Kingdom.” On the back is a recipe for a “delicious 2 lb loaf.”
The Canute packaging is a reference to King Canute of England, Denmark, and Norway, 995–1035 CE. Legend has it that to dispel his court’s claim that he was powerful enough to “command the tides of the sea to go back,” Canute directed his throne to be carried to the seashore—ostensibly near Southampton—and sat as the tide came in, commanding the water to “advance no farther.” When the tide paid no heed, the king’s point was made: sovereign power might be great, but nothing was greater than the hand of God. (Indeed, during Canute’s day the cause of the tide was still a complete mystery.)
Today the lead miller is David Plunkett, a retired stonemason with deep-set blue eyes and ruddy cheeks. I had missed the previous tide cycle, and the next wouldn’t start until six o’clock that evening, after the building was closed. Plunkett, however, invited me to stay. He and his apprentice, Andrew Turpin, would run the mill, and I would be put to work lifting sacks of grain and refilling the grist bin.
After returning from a dinner of stew and beer at the local pub, Plunkett flicked the tide gauge with his thumb. “We’ll be ready to fire up the wheel in about fifteen minutes,” he said as he pumped grease into the main waterwheel’s brass cap and donned a white apron. Turpin grabbed a bag of raw wheat supplied by a local farm and asked me to pour two scoopfuls in the grist bin. The two of them walked through the building, methodically adjusting valves, cables, and the two four-foot-diameter grinding stones, each weighing a ton, fabricated in France of composite granite. The massive timber-framed structure, some of it cobbled together or partially eaten by insects, reminded me of an old ship. As if below decks, I had to duck under low-slung oak beams and knee braces.
“Here we go,” announced Plunkett as he turned an iron valve opening the sluice gates. Laboring at first, the wheel eventually rumbled to speed. The whole place seemed to come alive, creaking and groaning like a ship at sea. Windows shook. Iron latches and levers rattled. A spoon and pencil chattered in a jam jar. Upstairs, the grist bin’s tick tick tick confirmed that grain was being fed to the grinding stones. When I looked up from the swishing and gurgling waterwheel, a stream of golden flour was pouring from the chute.
The waterwheel ran for four and a half hours. Through the windows, I watched the tide disappear from the harbor, leaving all the boats aground. The mill’s wheelwash gushed into the estuary like a whitewater rapid. Plunkett and Turpin were constantly tinkering with valves, watching, touching, listening. A fine powder had filled the air as soon as we started producing flour, settling on everything, including our eyebrows and lashes. The place smelled like baking bread, hot grease, and low tide.
A few times an hour, Plunkett put his hand under the warm flour spilling from the chute. Spreading it on his open palm, he’d run his thumb through it, feeling for temperature and texture. “What we’re after is a balance of wheel speed and distance between the two grinding stones,” he said. “If the stones are too close, the flour gets hot and sticky. If they’re too far apart or we’re turning too slow, the flour’s coarse.”
“How do you know when all the elements are perfectly tuned?” I asked.
“There’s a vibration that feels just right,” he answered. “I can feel the humming in my skull.”
The waterwheel shut down when the rising tide reached its axle and there was too much drag for it to continue turning. I drank a celebratory beer with Plunkett and Turpin at the local pub and caught a midnight train back to London, carrying a bag of fresh Canute Stoneground, flour of the tide. The train’s soothing hum reminded me of the tide mill and Plunkett’s words: “After fifteen years, I’m still amazed,” he had said. “There are no engines, no gasoline, no coal, no electricity except for a couple of light circuits. All this is powered by the moon and tides.”
The energy sources of fire, petroleum, coal, and their by-products have been used by humans for a long time—fire for 400,000 years, petroleum for 4,000 years, and coal for at least 3,000 years.
Petroleum was used by the Babylonians to make asphalt as early as 1894 BCE. Almost four thousand years later, Londoners were distilling it into kerosene to fuel streetlamps (replacing whale oil). Natural gas, a by-product of coal mining and oil drilling, was also used for lamps.
Coal, first burned in ceremonies by the ancient Romans, was used by London blacksmiths in the twelfth century. Its smelly, dirty properties were well known. When Queen Eleanor visited Nottingham in 1257, the air was so sooty she fled, fearing for her health. Forty years later, coal burning was banned because of its polluting qualities.
By the time Magellan set sail from Spain in the sixteenth century, Great Britain was facing perhaps the world’s first energy crisis. Wood, the fuel of choice for heating and cooking, was in low supply. Forests were shrinking.
Coal, dirty or not, was the ready answer. “By the mid-1600s,” writes Barbara Freese in Coal: A Human History, “Londoners did not merely welcome coal into their homes, they were desperate to have it.” Mined at nearby Newcastle and Tyne River, coal solved London’s energy crisis but at the expense of stifling air pollution. In 1700, addressing the insidious smoke that plagued London, essayist Timothy Nourse wrote of London, “There is not a more nasty and a more unpleasant Place.”
That was more than three hundred years ago.
The steam engine, invented in 1781 and fueled by coal, catapulted Britain and eventually the rest of the world into the Industrial Revolution. By the end of the nineteenth century, steam-fueled mills had largely displaced wind- and tide mills. The Eling tide mill itself was converted to steam in 1890. Thirty years later, unable to compete in the flour and textile industries, Eling was producing only animal feed.
Prior to the Industrial Revolution, the world’s consumption of fossil fuels was negligible. By the year 2000, our consumption had grown by a factor of forty, and by 2015 it had grown by a factor of eighty. In the overall global energy budget, 50 percent comes from coal, 20 percent from oil, 15 percent from natural gas, 5 percent from nuclear fission, and 10 percent from renewable sources such as biomass (wood burning, etc.), hydropower, wind, and the sun.
Accelerated fossil fuel use is tied to the planet’s population growth, and such use is tied to lethal concentrations of pollutants that have changed the planet’s chemistry and lessened the quality of life for everything that lives on it. A growing concern about this problem was best signaled by the landmark Paris climate deal in December 2015. But the awareness has been growing for years. In an August 2013 letter to the New York Times, four former Republican administrators of the Environmental Protection Agency (EPA) wrote, “There is no longer any credible scientific debate about the basic facts: our world continues to warm, with the last decade the hottest in modern records, and the deep ocean warming faster than the earth’s atmosphere. Sea level is rising. Arctic Sea ice is melting years faster than projected.” The letter calls for a reduction in carbon dioxide emissions and increased investment in clean, renewable energy. Signed by William D. Ruckelshaus, Lee M. Thomas, William K. Reilly, and Christine Todd Whitman (representing forty-three years of EPA leadership), the letter concludes: “The only uncertainty about our warming world is how bad the changes will get, and how soon. What is most clear is that there is no time to waste.”
From our Punta Arenas hotel conference room, the view of Magellan Straits is strikingly raw and elemental, offering no hint of an environmentally troubled world. How did we lose our way so quickly? What level of environmental health will we use as a baseline for recovery, if there is to be a recovery? Gareth Davies, who takes the podium next, begins as if his words were the next sentence of the New York Times letter: “I believe the world is in a hurry for us to come up with a better solution for energy,” he says, “because we’re not in a good place at the moment. The energy we use is killing the world.
“Only 10 percent of the world’s fuel supply currently comes from clean, renewable energy,” Davies explains. “And of that, only 2 percent comes from tidal energy. But these numbers are growing. In the next twenty years, I hope to see the renewable sector increase to 40 percent.” According to Davies and many of his colleagues, tide energy will probably remain a small but important part of that 40 percent. This is not because harnessing the tide is so difficult, but because in terms of raw available power, wind and solar far outstrip all the other fuels combined, renewable or not.
What tide energy does offer is predictability—more than most other renewables. The wind doesn’t always blow and the sun is sometimes hidden by clouds, but the tide always ebbs and flows.
“For tide energy to flourish,” Davies continues, “we will have to resolve many of the same issues we face with other renewables. Getting the engineering right—building devices that work—is just one of them. Launching and servicing the devices is another, and so is political support, both nationally and internationally. We need more mechanisms in place that provide financial support during this early—and expensive—development stage. Utility companies, which frequently have near-monopolies on supplying power, will have to change. Environmental concerns need to be addressed, and the communities that will live with these devices in their backyard have to be on board. For them it means jobs and cheaper, cleaner energy. But it also means making reasonable compromises for the sake of the big picture.”
From my time with Davies as well as my own research, I’ve learned to appreciate his cautious optimism. Technology is one of the obstacles for all renewable energy sources. Wind and solar technologies are far more advanced than marine technologies, still in their nascent stages. Designs similar to the Eling Tide Mill, a barrage across a tidal estuary, have been revisited several times in the past hundred years, often in response to a fossil-fuel crisis. Perhaps the earliest modern-day effort was in Passamaquoddy Bay on the border of Maine and New Brunswick, which has a twenty-six-foot tide and a network of inlets that could be blocked off by barrages to form inland “pools.” The hydraulic head of these pools could then be utilized to funnel water through electricity-generating turbines.
The U.S. government first studied Passamaquoddy in the 1920s but determined the engineering was too ambitious and costly. The effort was renewed a decade later during the Depression’s public works program, only to fizzle in the face of opposition from utility companies. However, with an estimated capacity of a thousand megawatts (enough to supply more than a million homes), the project has never really died. Over the next twenty years, various engineering schemes were proposed, some of which were joint ventures with Canada. An international commission report, released in 1961, concluded: “It is evident that construction of the tidal power project by itself is economically unfeasible by a wide margin. . . . Either alone or in combination with auxiliary sources, [the tidal project] would not permit power to be produced at a price which is competitive with the price of power from alternative sources.”
President John F. Kennedy was not convinced of the commission’s findings and asked for a review by the Department of the Interior. The department’s report recommended that the project proceed. “I am pleased to meet today,” said Kennedy from the flower gardens of the White House on July 16, 1963, “to discuss the report on the International Passamaquoddy Tidal Project submitted by Secretary Udall. . . . The report reveals that this unique international power complex can provide American and Canadian markets with over a million kilowatts of firm power.” Kennedy explained that New England’s electricity rates were among the highest in the United States, and the Passamaquoddy project could reduce those rates by 25 percent. “Harnessing the energy of the tides,” he continued, “is an exciting technological undertaking. . . . Each day, over a million kilowatts of power surge in and out of the Passamaquoddy Bay. Man needs only to exercise his engineering ingenuity to convert the ocean’s surge into a great national asset.”
Private utility interests again mobilized in response to Kennedy’s plan. A team of consulting engineers was hired to find flaws in the Department of the Interior report. Their rebuttal convinced the public that the project was too expensive, time-consuming, and loaded with engineering pitfalls. Between these criticisms and the emerging interest in nuclear power—at the time considered the next best and cheapest solution to high fuel costs—Passamaquoddy foundered. Kennedy’s bold advocacy of tide energy ended abruptly with his assassination in November 1963, just four months after his groundbreaking speech at the White House. His words are inscribed above EMEC’s door: “The problems of the world cannot possibly be solved by skeptics or cynics whose horizons are limited by the obvious realities. We need people who can dream of things that never were.”
In the twenty years that followed, barrage-type tide energy projects were completed in France, Russia, and Canada. The 240-megawatt French barrage was built in 1966 across the La Rance estuary near Saint-Malo in Brittany; the 1.7-megawatt Russian barrage was built in 1968 at Kislaya Guba in northeastern Siberia; the 20-megawatt Canadian barrage was built in 1984 in Bay of Fundy’s Annapolis Royal. These plants are still in operation today. Canada considered several more installations in the Bay of Fundy during the Arab oil crisis of the mid-1970s, but the plans were abandoned when scientists like Peter Hicklin and Chis Garrett showed that they would have adverse affects on the tidal and biological systems.
The good news about barrage-type tide energy projects is they generate large amounts of electricity (at 240 megawatts, La Rance produces two hundred times more electricity than any single existing nonbarrage tide project). But barrages have fallen from favor due to their astronomical building costs and negative effects on the environment. Because they function like a dam, they block fish migrations and interfere with the natural tide exchange between land and sea, causing severe upland silting, which suffocates vibrant estuarine ecology.
Tide barrages have not gone away, however. In 2011 Korea opened the 254-megawatt Sihwa Lake Power Station, overtaking La Rance as the world’s largest. Proposals for a barrage across the Severn River, which separates England and Wales, have been considered since the nineteenth century; in 2013 the latest proposal was declined because, according to the review committee, the developer had failed “to answer serious environmental and economic concerns.” A 250-megawatt tidal energy lagoon, a modified barrage designed to generate electricity during both incoming and outgoing tides, is also proposed for Swansea in South Wales.
The approach to tide energy has changed in the last thirty years. The newest efforts have moved away from expensive and ecologically disruptive barrages toward devices that sit below the surface in a tide channel and harvest energy from the incoming and outgoing currents. This approach is called in-stream, a term that applies to both tidal and river installations, although tidal is far more developed. Most of these in-stream devices look like an underwater windmill, turning in the current the way a windmill turns in the wind. But some sit on the surface and take advantage of the tide’s vertical rise and fall, and a few are designed to soar in the water column like a kite or a bird. The electricity these devices generate is transmitted to shore by heavy cables and from there to a nearby power grid.
Generally, in-stream devices, or machines, come in three sizes: commercial, community, and micro. Commercial-scale devices are huge—with blades up to seventy feet in diameter—and are designed to generate as much electricity as possible: five hundred kilowatts and up. Once these commercial units achieve a certain level of success, they’ll be installed in arrays on the ocean bottom, like a wind turbine farm.
When I was in the Orkney Islands, I stumbled upon a couple of these devices being repaired on a commercial dock near the town of Kirkwall. One, owned by Rolls Royce, is a bulbous orange thing about the size of a very large recreational vehicle, with three fat propellers sticking out one end. When launched, the machine is towed on a barge and positioned above a turbulent tidal channel. During the ten or twenty minutes of slack water, the machine is lowered by crane through the water column before touching down on its seabed cradle. All this must be done with the precision of landing a space module. If something goes wrong—the weather turns or a widget malfunctions—the mission is aborted, at huge expense, and everyone goes home until the next slack tide.
On the dock for repair, the Rolls Royce machine sat awkwardly on chocks high in the air while welders and engineers worked day and night to get it back in the water. It was fenced in like a large zoo animal, with worklights mounted on steel scaffolding and arm-thick cables strewn on the ground. The crew kept mum when I asked questions, though I did learn that another machine, twice the size of this one, was under construction outside London.
Down the dock, another device was tied alongside, this one owned by Orkney-based Scotrenewables. It too is tubular, but 120 feet long and slender like a submarine. Its yellow paint looked fresh. It has folding “wings,” each with a two-bladed turbine that tucks in close while the unit is towed from site to site, or from site to dock for repairs. Unlike many of the devices being tested, this one stays on the surface and unfolds its wings into the tidal currents below.
Devices are in and out of the water regularly, being repaired, tuned, and tweaked. Many are tested at EMEC in the Orkney Islands, but some are tested independently or at the Fundy Ocean Research Centre for Energy (FORCE) in Canada’s Bay of Fundy. Like EMEC, FORCE is an international testing site funded largely by the government. Located in Minas Basin near the town of Parrsboro, Nova Scotia, it has four berths to lease. The first device, designed by OpenHydro, was installed in 2008 and pulled a year later for repairs. Minas Basin’s strong currents make this site one of the more challenging test locations.
The SeaGen in Strangford Lough.
The commercial device with the longest continual in-water operation is SeaGen, installed in 2008 at Strangford Lough, Northern Ireland. (Strangford Lough was also the site of the eighth-century Nendrum tide mill, the oldest on record.) SeaGen, built by Marine Current Turbines, has a center tower drilled into the seabed that rises thirty feet above the ocean’s surface. Two swiveling arms, each with twin fifty-four-foot blades, extend below the surface. When rotating at capacity, the SeaGen can generate 1.2 megawatts of electricity, enough for 1,500 homes.
A sampling of tide machines, all under development.
While there’s a strong financial push to develop commercial-size machines, midsize devices are also being developed for remote communities and coastal aquaculture. New York–based Verdant has had community-scale tide machines in the East River since 2002 and is planning to install more in the future. Smaller devices—known as microscale—are designed to generate just a few watts, enough for a navigation light or an oceanographic sensor. Some are so small they flutter in the tidal stream like a fishing lure.
No matter the size or approach, these devices must hold steadfast in almost impossible conditions—where Magellan and no other right-minded sailor would want to linger. First, they must endure the six-hour storm of an incoming tide, with heavy currents corkscrewing in every direction. Then they must withstand the same storm from the opposite direction—the outgoing tide—for another six hours, all while dependably producing and delivering electricity to shore.
Every step of this process is under development, from blades to gaskets, from hinges to couplers to cable stout enough to carry the electrical loads. And, as if that’s not enough, there are the challenges (and frustrations) of obtaining licensing from regulatory agencies, negotiating with reluctant utility companies, securing permits and offshore leases, weighing environmental impacts, and evaluating potential interference with established uses such as fishing, shipping, coastal security, and recreation.
“Sometimes I get so discouraged I want to quit,” says Chris Sauer of Maine’s Ocean Renewable Power Company (ORPC), whose 150-kilowatt machine, TidGen, recently completed a continuous one-and-a-half-year in-water, grid-tied operation in Eastport, Maine, the first of its kind in the United States.
Developers are generally skittish about divulging project information, but over breakfast on the first day of the Punta Arenas workshop, Sauer shares the details of ORPC’s history. He will give a presentation for the group later today, but at the hotel café he is surprisingly candid about the story behind the story. What he tells me is about one company and the evolution of one machine, but it’s representative of the experience of every developer, big or small.
Sauer, in his late sixties, is tall and thin. His full head of frizzy gray hair accentuates his zeal, especially for marine renewables. With a background in engineering and business management, he spent forty years in the coal, oil, and natural gas industry. He was retired and living in Florida when in 2004 he was asked to consult about generating power from the Florida Current. “I knew nothing about the ocean,” he says. “But I thought, if we could use the ocean to generate electricity, that would be something!”
A couple of years later, Sauer took over ORPC and submitted his first design concept to the Navy for review. “They hated it,” he says. “Among a long list of things, they said the blades were too big to withstand the stresses.” With their help, Sauer designed a new machine using cross-flow turbines and a high-torque, low-rpm generator, all to minimize stress. A scaled-down version was built and tested in the summer of 2007. “It barely worked,” says Sauer, “but we got enough data to know the basic turbine concept was sound.” His team also realized that cross-flow turbines, which look and operate like a manual lawn mower, rotate the same direction no matter which way the current is flowing. “So, bingo,” Sauer says, “we can do tidal!”
Ocean Renewable Power Company’s TidGen, designed to rotate on both incoming and outgoing tides.
From that point, ORPC’s focus shifted from offshore currents to in-stream tidal and river. The company applied to the U.S. Federal Energy Regulatory Commission (FERC) for permits to launch machines in Cobscook Bay in Eastport, Maine, and Cook Inlet in Alaska. “I had been to Alaska during my days of working with fossil fuels and knew how strong the tidal currents were. Other than the Bay of Fundy, Cook Inlet is probably the most energetic site in North America.”
The next machine was tested for a full year in Cobscook Bay. It generated electricity, but it was too scrambled to be grid-compatible. “You’ve got to be able to plug your hair dryer into these things,” says Sauer. An improved machine went in the water in 2010 and came out a year and a half later. This one was fraught with problems too—finicky electronics, failed connectors, alignment issues—but it succeeded in delivering grid-compatible electricity.
In 2012 ORPC got its pilot-project license for an installation in Cobscook Bay, the second issued in the United States for tide energy but the first actually built. “It was an enormously time-consuming and expensive process,” says Sauer. “FERC deals with inland dams, so tidal energy was completely new to them. They’re good people, but this was so new they didn’t even know what questions to ask.” ORPC launched the TidGen that summer in Cobscook Bay and left it in for a year, where it supplied enough power for about thirty homes.
Encouraged, Sauer began looking at the international market: Canada, the United Kingdom, France, Japan, Taiwan, China, Korea. All these countries have coastal zones with large tides and currents, and all are exploring tide energy, along with Australia, New Zealand, Norway, and Russia, among others. “These places are all vastly different,” says Sauer. “In each case, you have to ask a lot of questions: How much tidal energy is there? How accessible is it? Are there supporting marine facilities? What are the environmental concerns? Is there an electrical need, or load, nearby? What’s the political climate? Are there economic incentives? Finally, you have to ask if they like Americans, because not every country does.”
As we finish breakfast, Sauer tells me he’s drawn to Chile because it’s got great tidal resources and it’s friendly, politically stable, and market-oriented. “And,” he says, “I don’t see another tide company knocking them dead down here.”
When I ask which sites are likely to be developed first in Chile, he explains that it probably won’t be First Narrows in Magellan Straits. “It’s a good site, but too far from the grid,” he says, “and even if it could be grid-tied to Punta Arenas [the closest town], the loads here are not demanding enough since they use natural gas and not electricity to heat their homes.” Sauer believes the best site is Chacao Channel near Puerto Montt, about 1,500 miles north of Punta Arenas. “I don’t know if I’ve seen a better tide energy site than Chacao—anywhere,” he says.
Gareth Davies and his assistant Tom Wills took me to see Chacao Channel. We met in Santiago a few days before the conference and drove down the coast, stopping at Valparaíso, Concepción, and Valdivia where Wills and Davies gave presentations at universities and met with engineers and oceanographers to explore partnerships for Aquatera’s work in Chile.
As we drove into Puerto Montt, the closest city to Chacao Channel and the region’s commercial and industrial hub, I studied the landscape out my backseat window. Billboards flicked by advertising Husqvarna chain saws, fertilizer, Mack trucks, and Thule luggage racks. Fields were plowed under for winter. The ever-present Andes loomed in the east, and the snow-topped volcanoes of Osorno, Puntiagudo, Calbuco, and Hornopiren towered to the south and west. As we got closer to the port, signs advertising escape routes in the event of earthquake, tsunami, or volcano eruption were everywhere. On the wharf, a café owner who served us a lunch of fish soup and empanadas told us that several years ago all three warnings sounded at once. “Where do you run to, then?” she asked.
From Puerto Montt, we drove west toward the open sea and arrived at Chacao Channel by late afternoon, in time to catch a small ferry that crosses the channel to Chiloé Island. The day was overcast, but I could see in all directions. The mustard-colored bluffs and brilliant green fields of Chiloé, a farming and fishing community, are only a few miles on the other side of the channel. Toward the west, the gray-blue ocean spilled into the sky. The volcanoes I had seen earlier were still prominent. The smells of diesel and fish in Puerto Montt’s inner harbor gradually gave way to aromas of heavy salt air and evergreens.
Davies wasted no time making his way to the boat’s bow. He noted a seal or two, a grebe, a few white-breasted cormorants, and a flock of gulls. The current was ebbing, like a large, deep river lumbering implacably toward the sea. “I’ve wanted to see this place for a long time,” Davies said. What makes this site so perfect, he explained, is that it’s in a rural area yet close to an industrial port with a large electrical load. (Puerto Montt’s power grid connects to Santiago and Valparaíso, where about 50 percent of Chile’s population lives.) The channel itself is long and wide, 150 feet deep, fairly flat-bottomed with few large reefs or obstructions. It’s protected from the open ocean and, the salient point, has a twenty-one-foot tide with five to six knots of “orderly” (meaning not too turbulent) tidal current. When I asked how much energy was in the channel, Davies replied that tide models showed about 600–800 megawatts. “Not all that is extractable, though,” said Davies.
Scientists agree that 3.5 terawatts of global tide energy is the correct theoretical measure of the total, based on the physics. The electricity that a single site like Chacao Channel can actually generate is much less, given the technical, social, economic, and environmental realities. “The best sites in the world usually have between 500 and 1,000 megawatts of theoretical energy,” explained Davies. “But from a practical view, we can capture only about 20 to 30 percent of that. It’s this practical view that everyone cares about. That’s the energy that can actually be delivered to your home, but it’s not easy to estimate that in advance of actually having a device in the water because there are so many technical and socioeconomic unknowns.”
The conference in Punta Arenas is Chile’s first attempt to get a handle on these practical issues. The government is well aware of the country’s extraordinary tidal resources but also aware of the realities of exploring uncharted territory. Addressing socioeconomic unknowns, for example, is one of the issues that must be confronted by project development, which is a process parallel to—yet very different from—device development. Device development is all about building a workable machine; project development is all about public process and securing the permits necessary to put the machines in the water. Most device developers want to focus only on engineering issues. They’re not usually trained nor do they have the resources to pursue onerous public and regulatory processes, such as seabed licensing and environmental risk assessments. This is where the test sites of EMEC and FORCE, as well as a few smaller test sites, come into play. At these sites, much of the project development is already done—public process completed, licensing secured, monitoring equipment in place, electrical cables installed, and so forth. Once an application for a test berth is accepted, a developer is free to undertake the challenges—and they’re formidable enough—of building and launching a workable device.
What these sites offer is not trivial. Good project development, especially in territory where the laws are unclear or nonexistent, is time-consuming and expensive. It took years (and millions of subsidized dollars) to get EMEC and FORCE up and running. To be successful, project developers need teams of scientists, lawyers, community leaders, engineers, and financiers. They also need people who are extraordinarily skilled at listening to and understanding the concerns raised by people who live and work near a proposed installation. A local biologist, for instance, might be concerned about the effects of underwater noise, electromagnetic fields, or potential collisions between rotating blades and marine mammals. A politician might focus on new jobs. Property owners may fuss loudly about visual impacts. A tribal leader might worry that a submerged device will interfere with the tribe’s “usual and accustomed” fishing rights.
“We’re all inventing this process together,” said Davies as we drove back to Puerto Montt, where we caught a plane down to Punta Arenas. “In Orkney, we had lots of public hearings and discussions with the community. Most people were on board right away, but there was a small group of stakeholders—environmentalists, fishers, recreational outfitters—who were worried about possible impacts. As a compromise, we agreed to install two machines and monitor them for three years. That test showed no negative impacts. Today, almost fifteen years after EMEC was established, the community is completely on board. More than that. They’re proud of what they’re doing. Over 300 people are employed in Orkney’s marine energy field, and a lot of the locals have invested considerable money in the projects.”
The project development process is the same everywhere in the world, although particulars vary. A site like Naruto Narrows in Japan has excellent tide energy, but it’s smack in the middle of a commercial tuna fishery. Many of Canada’s best west coast sites are in remote and unpopulated regions with small or no power load. Canada’s east coast, and specifically the Bay of Fundy, is what many call “the Everest of tidal energy.” But the claim is also its nemesis. Whereas five- to seven-knot currents are usually considered optimal, the FORCE test site in Fundy’s Minas Basin has an average of twelve knots, with peaks of more than sixteen knots. “That will rip a machine to shreds,” said Davies. And it has. The first device tested there, a sixty-foot-diameter OpenHydro turbine installed in 2006, lost its blades in the first three weeks. “The bad news about that,” a FORCE representative told me, “is we learned these machines don’t yet have what it takes to withstand Fundy’s turbulence. The good news is there’s more power down there than we thought.”
The Orkney Islands also have their challenges. They have tremendous tide energy resources, but the power cables connecting Orkney to mainland Scotland are already at capacity. They require a multibillion-dollar upgrade to justify permanent tide energy development in the islands. France has good tidal energy resources too, but the incentive for development is dampened by inexpensive nuclear-generated electricity (largely government subsidized). Government policies make all the difference in France and elsewhere, especially when research and development costs are high. Scotland, for example, has both “push” and “pull” mechanisms in place. “Push” mechanisms provide low-interest loans, grants, and other subsidies for start-up development. “Pull” mechanisms are market-driven and can take the form of tax credits. Scotland’s Renewable Obligation Credit is one of the most progressive pull mechanisms because it provides a larger credit to the least developed technologies: wave and tide.
Chile has already provided grants—a push mechanism—for “water-ready” projects, which will get devices in the water and working. But for the technology to mature, pull mechanisms are essential. Getting those in place will be one of Chile’s largest challenges because Chile’s electrical utilities are privately owned. The government can advise on practices, but by constitutional law it cannot impose regulations, such as feed-in tariffs, renewable energy credits, and so forth.
The United States has a basically supportive government and industry, but despite a few executive orders by President Obama, we have no renewable energy policy, which allows environmental regulations to trump development push. Our best potential sites are the San Francisco Bay; Puget Sound, Alaska; and New England.
A feasibility study commissioned by the City of San Francisco in 2006 determined the theoretical tidal power under the Golden Gate Bridge at 12–15 megawatts. The study concluded that only 10 percent of that was realistically harvestable. “The sensitivity of the Bay’s ecological system,” the report states, “limits the available extractable power from Golden Gate flows to between one and two megawatts.” The project has been shelved for now, as the cost of development far exceeds the value of the electricity it would produce.
Alaska’s Cook Inlet, where Chris Sauer and ORPC have an interest, has exceptional tidal resources, but the downside is severe weather, water-born debris (such as trees), and, due to oil revenues, little or no political incentive for developing renewables.
In Washington State, Snohomish County Public Utility District No. 1 (the twelfth largest PUD in the country) planned to install two eighteen-foot-diameter, 150-kilowatt machines. Under FERC permits, they would have been in Puget Sound’s Admiralty Inlet for three to five years, primarily to learn from the process, test the equipment, and gain additional information on environmental monitoring. This is an ideal site for many reasons: the average maximum is five knots; the depth is a consistent 180 feet; the bottom, composed of hard glacial clay, is fairly flat with few rocky outcroppings; and the load centers of Everett, Seattle, and Tacoma are close by.
After years of research, much of the political and technical preparations were in place, but due to funding shortages, the project was abandoned before the machines were installed.
Besides funding, the issue that may put a cold stop on tide energy development in Admiralty Inlet—and all of Puget Sound—is environmental. Three federally listed endangered species live there: salmon, rockfish, and the iconic killer whale. If the Snohomish test turbines had produced even a hint of adversity for one of these species, the machines would have been pulled.
“We left no stone unturned,” said Andrea Copping when I spoke to her several months earlier. Copping, who works for a laboratory run by Batelle Memorial Institute Research Center in Seattle, was part of the team offering technical assistance to Snohomish PUD. “They worked on this for eight years, beginning with public meetings up and down Puget Sound, as well as with the Suquamish, Lummi, Duwamish, and Tulalip tribes.” They evaluated seven different tide sites, applied for FERC licensing, and responded to concerns raised by U.S. Fish and Wildlife and the National Oceanographic and Atmospheric Administration (NOAA), the latter being the agency responsible for upholding the Endangered Species Act. “NOAA would ask questions,” Copping said, “like ‘What’s the risk that an orca will get hit by a rotating blade?’”
Because none of these questions had been asked before, Copping and her team would initiate a study and months later return to NOAA with an answer. Then NOAA would raise another question. “It went on and on,” said Copping. “After months of looking at the statistical possibility of an orca getting struck by a rotating turbine, we concluded the risk is very low. First, these tide devices sit about 150 feet deep. Marine mammals spend most of their time in the top 100 feet. Also, whales are smart. They’re aware of what’s around them and they’re unlikely to stick their head intentionally into a moving turbine, even if it’s moving slowly, as these devices typically are. Our studies show that if a whale gets struck, it’s most likely going to be an adolescent male whose curiosity is getting the best of him. Even then, the likelihood that a collision would be fatal is very, very small.”
“I’m afraid this is all going to end in tears,” said Canadian physical oceanographer Chris Garrett, who served on a recent U.S. Department of Energy Commission to assess marine energy potential. The commission’s report concluded that the United States could get up to one-quarter of its energy from tides. But Garrett doesn’t think it’s worth it. “There’s plenty of energy in the ocean. That’s not the problem,” he said during one of my several visits to his home near Oak Bay, on Vancouver Island. “The problem is that when you pencil out the costs to extract the small percentage of available energy, and then tally the energy and money that’s already been spent studying the subject, it doesn’t add up.”
Between presentations at the Punta Arenas conference, I mention Garrett’s comment to Davies. He takes a few minutes to consider his response. “Garrett is a highly respected scientist,” he begins, “but he’s looking at only one dimension of the picture. Can you think of a single technology that hasn’t been through a phase where the road ahead looks daunting, even impossible? What if we had given up on computers when they were the size of an elephant? Think of how long it took us to develop the airplane. We still don’t know to what degree tide energy is going to pay off, but it’s far too soon to give up.”
Davies’s comments reminded me of Magellan, who journeyed with five small ships and 260 men into a vast and unknown ocean-sea. Magellan’s greed and cold-heartedness may not be qualities most of us would praise today, but his unflappable courage and persistence in sailing off the edge of the known world are qualities that inspire.