March 20, 2005
ALEXANDER'S MARVELOUS MACHINE
It looks like an oversize eggbeater, but Professor Gorlov thinks his turbine can change the world.
NRDC: OnEarth Magazine
by Jill Davis
It seems impossible that anything of technological significance could emerge from the basement of Richards Hall, the engineering building of Northeastern University in Boston. It is a haphazard warren, home to discarded office chairs, old lockers, and unclaimed pencils, all covered in a coat of fine gray dust. But it is also the home of the Hydro-Pneumatic Power Laboratory, where a 73-year-old Russian-born mechanical engineering professor named Alexander Gorlov spent a decade redesigning one of the world's oldest and simplest machines, the turbine.
Smiling, Gorlov walks over to a cluttered corner of the lab and wheels out a gurney. Strapped to it is an object that looks remarkably like an oversize beater from an old hand-held mixer. Still, this is it, the Gorlov Helical Turbine, which may someday help turn hydroelectric power into one of the most important and environmentally benign renewable energy sources on the planet. Gorlov's turbine received the 2001 Thomas A. Edison Patent Award, given each year by the American Society of Mechanical Engineers, which hailed its potential "to alleviate the world-wide crisis in energy."
The first thing to understand is that this is not hydropower as we know it. Just as wind turbines harness the kinetic energy of moving air, Gorlov's turbine has been designed to harness the kinetic energy of moving water -- even slow-moving currents -- without the need for dams. Remove dams from the equation and electricity can be generated almost anywhere water flows--in man-made canals, tidal straits, the open ocean, and unimpounded rivers. "Ocean and river currents contain a huge amount of energy," Gorlov says. "The question has always been: How can we get it without destroying the environment?" He is convinced that his turbine provides the answer.
This innovative form of hydropower is so new that its pioneers haven't even settled on a name for it. Some call it free-flow hydropower; others kinetic, low-head, or simply unconventional hydropower. Gorlov's design is one of many jostling for attention and investors. Companies in the United States, the United Kingdom, Norway, and Canada are building and testing their own free-flow turbines, but while the engineering can vary wildly, developers agree that free-flow hydropower has enormous potential.
The amount of power that could be produced from ocean currents almost defies comprehension. The currents flowing through San Francisco's Golden Gate alone, for instance, could produce an estimated 2 gigawatts per day -- more than twice what the city needs at times of peak demand. The global potential is some 3,000 gigawatts, according to the United Kingdom's Department of Trade and Industry. The agency estimates that 3 percent of that total, or 90 gigawatts, is economically recoverable using current technologies.
In September 2003, a turbine built by the Norwegian company Hammerfest Strom became the first to send free-flow hydropower to a grid. Anchored in deep water off Norway's coast, where tidal currents are strong and constant, the Hammerfest turbine is massive, with three 30-foot-long blades. The United Kingdom has similar plans for its abundant ocean currents, and in 2003 pledged £960,000 ($1.8 million) to help Marine Current Turbine install a double-propeller turbine measuring 45 feet across off the coast of Devon. Verdant Power will soon install six of its turbines in New York City's East River, making the company the first in the country to send free-flow hydropower to the grid.
All of these machines are so-called axial-flow turbines. The type of turbine most often found on wind farms, they are shaped and operate something like a propeller. Gorlov's invention, however, is a cross-flow turbine. It spins much as you'd expect from its appearance, making it extremely versatile. It can be mounted either horizontally or vertically, stacked in rows like spools on a string, and placed in water as shallow as three feet. (Most axial-flow turbines require eight feet or more.) The blades of an axial-flow turbine will turn only if they face the current, whereas Gorlov's turbine will function regardless of the direction of the flow, ideal for tidal waters.
For its design, Gorlov credits in part French engineer Georges Jean-Marie Darrieus, who in 1931 received a U.S. patent for a turbine whose blade would be shaped in a way that was "analogous to that of the wings of birds." This, he knew, would increase efficiency and make the turbine spin much faster than the wind or water hitting it. On paper, the Darrieus turbine had magnificent potential, but the real world was too much for it. The ruler-straight blades had a tendency to pulsate wildly, rip from the axle, or snap in two. Gorlov corrected Darrieus's engineering error: By twisting the blades slightly, a bit like a strand of DNA, he eliminated the vibrations. Gorlov received his first patent for the turbine in 1994.
Today, the narrow blades are modeled on the airfoil profile of a Boeing 727 wing. That slight helical twist not only removes the vibrations but also makes Gorlov's turbine a champion spinner. Placed in a moving current, it kicks into motion almost instantly and within seconds will turn faster than the speed of the water hitting it. Tests conducted at the Marine Hydrodynamics Laboratories at the University of Michigan in 1998 and 1999 showed that the Gorlov Helical Turbine will take off in water moving as slowly as two knots and can capture about 35 percent of the kinetic energy of the current.
For all the documented potential of free-flow hydropower, U.S. companies, such as the San Antonio-based GCK Technology, which bought the rights to Gorlov's turbine, face some formidable political and economic realities. Federal funding for hydropower research and development in 2003 amounted to $5 million, but free-flow projects received exactly zero. The only R&D money for free-flow hydropower in the United States comes from private investors willing to shoulder the risk and from a handful of states, including New York and Massachusetts, that administer their own renewable energy funds, paid for by a small surcharge on residential electricity bills.
The rising cost of traditional energy sources, increased concern over both energy security and the environmental impact of fossil fuel use, and new policy incentives such as renewable portfolio standards (which require that a certain percentage of electricity be derived from a renewable energy source) have all combined to sharpen competition. "There are literally hundreds of clean-energy technology companies fighting for public and private money right now," says Dan Reicher, president of New Energy Capital and assistant secretary of energy in the second Clinton administration.
The federal budget line for renewables peaked under Clinton and has now declined, with most funding being shifted over to hydrogen research. That may sound like a good thing, but developing hydrogen is a very long-term solution to energy problems that need fixing now. The shift in priorities, notes Reicher, comes at the expense of core renewables such as wind, solar, and biomass, which could provide solutions in the near term.
Developing a new hydroturbine is not as simple as, say, developing a new kitchen gadget. Lewis Branscomb, professor emeritus of public policy and corporate management at Harvard University's John F. Kennedy School of Government, has spent years studying the movement of perfectly good ideas into the marketplace and has concluded that all inventions, before becoming commercial products, must successfully cross a pernicious place he calls the Darwinian Sea. (Others, less optimistically, call it the Valley of Death.) On one shore is the invention and its creator; on the other shore is the market economy, mass production, and wealth. Branscomb's sea is "full of sharks and shoals and storms" -- funds can dry up, parts can break, regulations can bog an idea down, investors can decide that there's no market -- and few inventions manage to complete the journey.
In 1995, the National Institute of Standards and Technology's Office of Technology Innovation recommended that the Department of Energy consider supporting Gorlov's work. But that support did not materialize. Two years later, Gorlov conducted the first real-world test of his turbine in the Cape Cod Canal, where he experimented with models with two blades and three and with varying amounts of twist, looking for the design that would spin most efficiently in the current. Since then, in one pilot project after another, Gorlov has sought to prove to the world that his machine is commercially viable. The first projects were on a tiny scale. One early prototype powered a generator at the Tidewater Motel on the island of Vinalhaven, Maine; another was used to recharge batteries at a village in the Brazilian Amazon. Last summer, a turbine was lowered from a barge into the tides near Shelter Island, in Long Island Sound. The most substantial feasibility project in the United States, supported by a $500,000 grant from the Massachusetts Renewable Energy Trust Fund, was a three-month trial near Amesbury, Massachusetts, in which four Gorlov Helical Turbines were submerged in the Merrimack River.
Considering the limited scale of these projects, Gorlov can count himself lucky that the Republic of Korea is facing an energy crisis. In 1999, an article on his turbine appeared in the Financial Times, and South Korea's National Assembly invited him to deliver a presentation on his invention. There were good reasons for the interest: South Korea's energy demands are growing at about 4 percent each year, and aside from a single natural gas field and some reserves of very low-grade coal, the country has no fossil fuels. To meet the burgeoning need for electricity, it relies heavily on imports and is planning to build several more nuclear power plants in the next decade. (It already has 19.)
However, the Korea Peninsula also happens to be home to some very fast-moving water. Soon after Gorlov's speech, the government pledged 40 billion won ($34 million) to develop a free-flow hydropower project driven by the Gorlov Helical Turbine.
On March 19, 2002, the Korean Ocean Research and Development Institute lowered the first Gorlov turbine into the Uldolmok Strait, a tidal channel that runs between the western coast of the Korea Peninsula and Jindo Island. The strait is famous for its roiling tidal currents, which can rip through the corridor at 12 knots. Gorlov showed me a low-resolution video of the event on his laptop computer. During a lull in the current, workers struggle to get the turbine in the water before the tides come in. Just as it is secured, the murky brown water begins to surge and the blades start to move. Soon they are spinning wildly, cutting up the water, sending frothy chop into the air. Offscreen, workers shout with excitement.
Four months later, the institute hooked up the turbine to a generator. A second video shows the turbine spinning in the night. A light shines over it, using electricity produced by the tides of the Uldolmok Strait. It's hard not to compare the event with one that took place in Appleton, Wisconsin, in 1882. On September 30 of that year, H. F. Rogers, a paper magnate and Edison supporter who had built the world's first commercial hydroelectric plant dam on the Fox River, used his Vulcan Street plant to produce enough electricity to light a single house. It was reported that "men jumped up and down and screamed like school boys."
Last fall, South Korea commenced the second phase of the project, when it installed a 15-foot turbine in the strait. During this phase, it hopes to produce up to 1,000 kilowatts of power that will be sent to Jindo Island, with a population of some 40,000. If that goes well, the government plans to install thousands of Gorlov's underwater turbines, hoping they can harness from Uldolmok and the surrounding oceanic streams up to 3,600 megawatts of power -- about equal to the output of four nuclear power plants.
The success of the Korean project may largely determine the commercial future of the Gorlov Helical Turbine. Experts point out that the underwater environment is harsh and unpredictable, full of sediment, corrosive agents, and unforeseen events. "How long will the equipment hold up?" asks Joseph Sayer, a project manager at the New York State Energy Research and Development Association. "What happens if there's a storm? What about a log?" And of course each body of water is unique.
Yet another issue must be addressed if environmentalists are to embrace Gorlov's turbine. Richard Roos-Collins, a senior attorney with the Natural Heritage Institute in San Francisco and an enthusiastic backer of hydrokinetic technology, acknowledges that "if it turns fish into sushi, then it's got the same problem as wind power." (For example, the windmills at California's Altamont Pass Wind Resource Area kill up to 1,300 birds of prey a year.) Gorlov insists his turbines will create a pressure barrier that will keep fish away from the blades, but he has yet to prove it. Two summers ago, Verdant Power placed monitoring devices on a single turbine and saw fish swimming around it. But what happens if fish encounter a whole field of whirling turbines?
None of these questions has stopped Gorlov from envisioning a world spinning with helical turbines, and that is a good thing. He imagines thousands of his turbines anchored near remote waterside villages, providing electricity to areas where there is no grid. He imagines pods of them linked together in streams and rivers. Most ambitiously, he imagines floating power farms that would harness the kinetic energy of the world's major ocean currents. "The Gulf Stream contains enough energy for all of North America," he says. Imagine a block of 656 Gorlov Helical Turbines anchored off the coast of Florida, where they could not only capture the enormous energy potential of the Gulf Stream, which carries some 80 million cubic meters past Miami's front door every day, but also produce hydrogen through the electrolysis of ocean water.
Concerns about money seem to irk Gorlov. "Perhaps it's reality that people first tend to compare the cost of installation and manufacturing, but think about it: We're not poisoning our air, our water, our environment." Who can argue with that?
http://www.nrdc.org/onearth/05spr/gorlov1.asp
