For the last 40 years, the Ovshinskys have been a leading name in the technology of amorphous and thin-film silicon, with technological developments impacting on everything from personal computers and roll-out photovoltaics to hybrid cars and hydrogen storage.
For the last 40 years, the Ovshinskys have been a leading name in the technology of and thin-film silicon, with technological developments impacting on everything from personal computers and roll-out photovoltaics to hybrid cars and hydrogen storage. Harvey Wasserman reviews the contribution and future plans from one of the pioneers of renewable energy technology.
In an unassuming brick building set back from a busy suburban midwestern highway, in an area home to what some call ‘Automation Alley,’ the future of solar energy — and of artificial intelligence — is intriguingly in play. And in a quiet industrial park nearby, in one of roughly a dozen facilities scattered through southeastern Michigan to house the brainchildren of pioneer inventor Stanford Ovshinsky, the rechargable nickel-metal-hydride (NiMH) battery (used worldwide in hybrid cars) is being advanced. An all-hydrogen hybrid sits in the garage, ready to spin visitors around the block, while a revolutionary metal-hydride fuel cell is being developed to challenge the Permeable Electrolyte Membrane (PEM) technology that now dominates the industry.
Indeed, there may be no single renewable energy research, development and production consortium with greater range and impact than Ovshinsky’s Energy Conversion Devices (ECD) industries, and its Ovonics off-shoots. They are among the most controversial, diverse and daring of any players in today’s fast-changing world of renewable energy.
Unlike our ride in the H-hybrid, if the past is any indicator, the future of Ovonic innovations is unlikely to be smooth or predictable. But it is almost certain to be hugely innovative and productive.
Electronics go solar
“The term Ovonics means ‘Ovshinsky-electronics,'” explains ECD’s co-founder. Already a staple of the green power lexicon, the word describes a multiplicity of endeavours pioneered for nearly a half-century by Stanford Ovshinsky and his wife Iris. A PhD researcher and bio-chemist, Iris recently passed away at age 79 (see box below).
Since ‘giving-birth’ to ECD in January, 1960, the Ovshinskys have pioneered the art, science and industrial applications of disordered, amorphous materials. Virtually untapped before the Ovshinskys began their work, these materials — primarily silicon — are now at the heart of the information age, as well as the prime ingredient in the Ovshinskys’ ‘floppy’ amorphous photovoltaic cells.
Stanford began his career as an inventor of machines in Akron, Ohio. The company he founded “helped bring in automation in the 1950s,” he says. But when Ovshinsky was offered “a deal I didn’t think I could refuse, to be head of R&D at an automotive supply company,” he moved to Detroit.
|The Ovshinskys have had an enormous impact on the development of environmental technologies, making advances in thin-film PV and hydrogen fuel cells. (mother earth news)
ECD made its mark on the computer/renewable age with breakthrough 1960s inventions in the use of silicon — these opened the door for disc-based re-writable memory and the chip-based home-scale personal computer. In November 1968, Ovshinsky published a much-anticipated scientific paper on the use of disordered silicon as a switching device for information processing and storage.
Heralded on the front page of the New York Times, Ovshinsky’s announcement became a landmark in the development of a series of inventions that helped make possible the re-writeable memory disc and silicon-based internal memory chips. Among the ‘fruits’ of his discovery, said the Times, would be “small, general-purpose desktop computers for use in homes, schools and offices,” and “a flat, tubeless television set that can be hung on the wall like a picture.” Ovshinsky’s work, the article added, represented “totally new knowledge” that would also find expression in an “electroluminescent screen.”
The on-going computer work of ECD’s subsidiary, Ovonics Universal Memory (OUM), includes a joint-venture arrangement with Intel and multi-level “cognition” memory devices that transcend the standard binary systems of storing information. These multi-level technologies open the door further into the uncharted world of artificial intelligence. As IT pioneer Takeo Ohta puts it, Ovshinsky “is the Great Father of Phase-Change memory.”
Decarbonization with amorphous PV
The connection between computer chips and photovoltaic cells may seem exotic. But it rests at the core of what Ovshinsky calls “the twin pillars of the global economy: information and energy.”
On the energy side, says Ovshinsky, “it’s all about decarbonization. Everything that burns can be replaced with hydrogen. Whether you are burning wood or whatever, hydrogen is where the energy comes from. The rest of the stuff is gunk that you want to get rid of. So why not go straight to the hydrogen?”
With closed loop system diagrams dating back forty years, Ovshinsky says “we are the only company with a proven product in every part of the hydrogen system,” including PV, NiMH batteries and solid-state hydrogen storage systems, hydrogen-based fuel cells, and vehicles that use hydrogen for internal combustion.
With breakthrough solar energy R&D funded in part by its IT work, ECD now dominates world production of thin-film amorphous silicon cells for converting sunlight to electricity.
The basics of the photovoltaic process have been known for more than a century. As a working device, the PV cell became a tangible reality in the early 1950s, when the Bell Laboratories in New Jersey successfully deployed some of the first working units on Vanguard satellites. (In fact, the very first Bell PV cell remains here on earth, and can occasionally be seen at solar energy fairs, where it still — after more than fifty years — generates current, with no apparent end in sight).
|Inside the ECD-Ovonics factory. (All remaining images: ECD Ovonics)|
But work in the mainstream PV industry has focused mostly on crystalline silicon wafers that are rigid and more expensive. Enormous progress has been made, and millions of such cells are now deployed worldwide as part of a fast-growing multi-billion-dollar industry.
Conventional wisdom has been that the industry will be dominated by such cells, mostly encased in glass and mounted on buildings or in free-standing arrays. With huge investments in place and ever-higher levels of efficiency being achieved, many expect crystalline PV to dominate the future of generating electricity with direct sunlight.
Ovshinsky sees a somewhat different picture. “We are the only company making real money on PV,” he says. “We don’t use any crystalline silicon, and we are not at all involved in the price of silicon,” (which has been rising rapidly).
Uncertain raw material supply and high production costs are key drawbacks for crystalline silicon, says Ovshinsky. Growing ingots of crystalline silicon is a lengthy, energy-intensive and expensive procedure, as is the precise process of slicing the ingots into wafers. The wafers are then fragile and brittle, and must be mounted and housed in heavy metal and glass casings for deployment on rooftops and in stand-alone arrays.
Because they must be connected in series, the shading or breakage of a single cell can significantly cripple the conductivity of an entire array. Lattice mismatches, adds Ovshinsky, prevent triple-junction manufacturing. Crystalline cells also lose efficiency at the high temperatures often experienced on rooftops, where PV gets its most frequent deployment.
The advantages of flexible, amorphous silicon-based PV are thus numerous, says Richard Blieden, Director of Government & International Sales for ECD’s United Solar Ovonic solar division, popularly known as Uni-Solar. Uni-Solar makes and markets Ovonics amorphous PV cells throughout the world.
Meeting in a conference room at the Uni-Solar production facility in Auburn Hills, Blieden explains that Ovonics’ triple-junction technology produces PV that is far thinner — less than one micron — and more flexible than its crystalline counterparts. At 0.7 pounds per square foot (3.4 kg/m 2), the Ovonics PV sheets are also considerably lighter than glass-encased wafer arrays.
A veteran of a quarter-century’s work in Ovonics, Blieden describes the triple-junction design as the means by which the Uni-Solar cells cover a broader range of the light spectrum for energy production. “We capture red, green and blue light far more efficiently than crystalline cells,” says Blieden. That allows the Uni-Solar PV to operate with less light, firing up earlier in the morning and “going to bed” later in the evening.
The triple junction technology involves three layers of silicon and germanium materials for red, three layers of pure silicon for blue, and three more layers of a different mixture of silicon and germanium for green. “The three cells cover the entire solar visible spectrum. They are also far more effective at high temperatures,” says Blieden.
“Our product can be as thin as 0.3 microns, versus 100 microns for crystalline cells,” he adds. “Amorphous PV is also far less energy-intensive to produce, and can pay back the energy it took for production within 17 months. The silicon is used in very minute amounts, which protects us from shortages and a fluctuating market.”
|Thin-film PV on the roof of a building in Germany.|
“Our production costs are well below any other PV product, “says Ovshinsky. “Our problem is keeping up with demand.”
Uni-Solar’s advocates are firm in their belief that their amorphous “floppy” product is superior to crystalline wafer PV. “Everyone knows the future is with amorphous technology,” says Ovshinsky.
However Ovshinsky believes the real competition is with fossil fuels and nuclear power. “I don’t want to attack crystalline,” he says. “But the system cost for nuclear power is far from being an answer economically. It creates terrible dangers, such as break-ins, explosions, and so on” he continues. “No-one has solved the waste storage problem, and Edward Teller (a leading US nuclear research pioneer) says if you take into account government subsidies, it’s the most expensive source of all.
“There is only one source of energy that can actually solve the problem,” Ovshinsky says, “and that is the sun.”
Ramping up PV production
The Auburn Hills plant is an eighth-generation facility, capable of producing 30MW of solar cells per year. With the addition of a second 30MW plant in Auburn Hills, capacity will soon double. An additional 60MW unit will open in Greenville, Michigan, in 2007, while several other plants are on the drawing boards. Uni-Solar expects to have annual production capacity of about 100MW by the end of 2007, and 300MW by 2010.
Blieden runs through a recent PowerPoint presentation, showing a range of Uni-Solar installations including a 30 kW car port installation at the Santa Monica Civic Auditorium, a 90kWp rooftop in Nuremberg, Germany, a 300kW rooftop on the Beijing Museum in China. The largest installation of Ovonics PV to date is a 500kW project that (ironically) powers the pumping of oil at a site in the California desert.
To the west, a 705kW installation is now underway at the Long Beach Convention Center. Funded in part by grants from the Golden State, the array will save its owners some $231,592 per year at current electric rates.
|Since it uses so little material, thin-film PV (seen here on the Ovshinksy’s family retreat) is not directly affected by the global silicon shortage.|
United Solar Ovonics solar modules have been installed and activated in a 1MW array on a General Motors parts warehouse in Rancho Cucamonga, CA. Blieden explains that this project was privately financed under a long-term power purchase agreement in which General Motors purchases electricity produced from the array rater than fund the up front capital costs. This installation is expected to provide up to half of the building’s electricity needs, and to reduce overall electricity costs.
The anonymous nature of the Auburn Hills facade does not prepare a newcomer for entering into the factory facility. It is a spotless, imposing, hauntingly quiet pair of open halls, with thirty-foot ceilings (10m) and surprisingly few workers. Its centrepiece is an automated 350-yard-long (320m) production line where the PV materials are applied to a continuous 6-tonne roll of stainless steel base, 1.5 miles (2.4km) long for a total of 9 miles (14.4km) of solar cells.
This plant is designed to run for 62 consecutive hours while rolling out those 9 miles of usable photovoltaic surface in a single cycle. The assembly line looks like a very long angular archway, with a high-tech press running down one side. There is a heavily computerized control room and a packing and testing area in an attached hall. “All the PV is subjected to performance testing before it goes out,’ says Blieden. ‘We get virtually zero rejection, and very few returns.”
The finished steel-backed PV is chopped into one-square-foot (929 cm 2) slabs which are converted to individual 62W solar cells. Twenty-two of these cells are interconnected into one eighteen-foot-long (5.5m) module, capable of producing 1356W of power. These can be packed in long, narrow wooden crates that go out on trucks.
But they can also be packed in rolls which are shipped in cardboard boxes that fit on pallets. Looking a bit like circular hay bales, these rolls are meant for direct rooftop installation.
“A tremendous advantage of Ovonic Amorphous Silicon Thin Film Photovoltaics is that they lend themselves so completely to the concept and applications of building integrated photovoltaics (BIPV),” says Ben Ovshinsky, ECD’s West Coast Representative. “In the concept of BIPV, the building is the photovoltaics, and the photovoltaics is the building.”
The key, he says, is that the solar collecting elements are “seamlessly integrated into, with, and as, the building structure itself. In the case of a roof, the photovoltaics is the roof, and the roof is the photovoltaics. They are totally integrated in form and function, as one product, in one (unified) application.”
Ben Ovshinsky adds that flexible amorphous PV is easier to use than conventional silicon arrays, “which require heavy, fragile and breakable, framed glass modules” which must be “expensively and awkwardly mounted” on rooftops and walls.
Furthermore, Ovshinsky says that amorphous PV’s “form-flexibility, very lightweight, near-destruction-proof ruggedness” allow it to “be easily hung on, or as, vertical curtain walls and exterior and facade surfaces of buildings, and shade surfaces and even windows, as well as being the roof. Our thin film applications adapt particularly well to curved architectural features and building surfaces.”
Such PV modules “can indeed stand in for rooftop shingles,” says Blieden. “They are flexible, glass-free and immune to damage from the likes of hail and vandals. They do double-duty as all-weather coverings and power generators, and can allow the construction of new buildings with considerable degrees of flexibility and self-sufficiency. They are clearly destined to play a big role in the future of renewable energy.”
From solar cells to H-Cars
A few suburban miles from the Uni-Solar facility is the ECD corporate headquarters, and the garage in which its hydrogen vehicles reside. Our arrival is greeted with an invitation to leap into a smooth-riding four-door compact. Like nearly all hybrids on the road today, it is fitted with an Ovonic Nickel-Metal-hydride (NiMH) battery. But instead of burning gasoline, this pioneer green machine moves on hydrogen.
“Except for some traces due to lubricants,” says Ben Chao, the CO2 emissions from this vehicle are virtually nil. “It is the embodiment of a successful completion of the hydrogen loop.”
Director of Alloy Testing Development at Ovonic Hydrogen Systems, Chao says this pioneer hybrid can travel about 200 miles (320km) on the 3.6kg of hydrogen stored on board. “A kilogram of hydrogen has roughly the energy content of a gallon of gas,” he says. “A Prius hybrid can get about 52-54 miles per gallon of gas (21-22km per litre). If it burns hydrogen, it gets 54-56 miles (86-90km) per kilogram. We’d like to go to 65-70 miles (104-112 km) per kilogram, and with sufficient funding we believe we could do so in a about a year.”
“Storing hydrogen in the Ovonic solid materials only requires one-thirtieth the volume as does compressing the hydrogen to 200 pounds per square inch,” says Chao.
Ovonics is involved with developing a mix of 30% hydrogen with 70% natural gas to reduce CO2 emissions at the tailpipe. The city of Akron, Ohio, has 67 buses running with compressed natural gas, and is “very interested in running with the Ovonic mix,” says Chao.
|Stan Ovshinsky (centre) holding a flexible solar module.|
There are other potential users throughout the world, he adds. “For instance, Chengdu, China, has more than 20,000 taxis that are currently burning natural gas. These can be easily adapted to add hydrogen to the natural gas.
“Ovonics has also stared providing hydrogen canisters to Jadoo Power, which integrates them with a small PEM fuel cell to power professional cameras for use in film making. It provides a three-times longer run time than the conventional re-chargeable batteries,” says Chao.
In Arizona, off-peak power is being used to generate hydrogen which is then stored for use in powering vehicles. The Ovonics vision is that hydrogen will be created for use in vehicles with green power, including, among other things, its Uni-Solar PV. “Generating hydrogen from carbon-based fuels is not the way to go,” says Chao. “Using water and any available renewable sources, such as solar energy, to produce hydrogen is the ultimate energy solution.”
The hybrid battery
For the moment, the centrepiece of the Ovonic internal combustion hydrogen hybrid is its battery. The nickel-hydride/NiMH device is standard issue now in hybrids all over the world, says Chao. The Ovonic Battery Company, an ECD subsidy, and its Cobasys joint venture, are tied into partnership arrangements with Honda, Sanyo, Chevron and a score of licencees from around the globe.
A dozen or so different types of battery have been in play, one way or another, in the booming field of electric and hybrid cars, including sodium-sulphur, lithium-iron-sulphide, zinc-bromine, zinc-chlorine and lead-acid, long a mainstay in the battery business.
One key Ovonics executive says lead-acid has largely dominated because it has a track record, is in large-scale production, and is relatively cheap. But the Ovonic NiMH design continues to advance because it has demonstrated a high power-to-weight/volume ratio and is durable enough to take what he calls “a lot of abuse.” The metal-basic storage technology is also proving to be safer than both lead acid batteries and compressed hydrogen.
The fuel cell of the future?
General Motors in now buying the nickel-hydride battery for the Saturn SUV. Cobasys is in a joint venture with Chevron to build batteries near Springsboro, Ohio.
Yet its companion, the metal-hydride fuel cell, still dwells in the realm of controversy. Ovshinsky refers to it in a recent paper as “a fundamentally new approach to fuel cells, providing for intrinsic energy storage functionality in the fuel cell stack and unique performance attributes utilizing non-noble metal catalysts as a low cost approach. Attributes include instant start and the unique capability to store regenerative braking energy in the fuel cell stack, also with excellent low temperature operation.” The new approach also features “alternative reaction pathways [that] enable higher voltage operation with the potential for dramatic improvements in efficiency.”
As the Ovonic amorphous silicon is still a challenger to crystalline silicon, and as the NiMH battery has been (until the hybrid car came around) a junior partner to the lead acid battery, so the metal-hydride fuel cell seems the outlander to the Polymer-Electrolyte-Membrane (PEM) fuel cell, at least for the time being.
“PEM dominates the field right now,” says Dennis Corrigan, President and CEO of the Ovonic Fuel Cell Company. Among the companies with serious commitments to PEM technology are Ballard, General Motors, Honda and Ford.
Fuel cell technology has been around since 1839. But the Ovonics fuel cell team, which includes about a dozen employees, is betting that the future is with metal-hydride fuel cells. “Nickel-hydride is a great catalyst for oxidizing hydrogen, and it can be also used to store hydrogen,” says Corrigan. “So we are now able to merge the fuel cell electrode with the battery electrode. This is the only fuel cell that’s also a battery.”
The key distinguishing structural feature of the Ovonics “regenerative” fuel cell design is in its anode and cathode. The anode accepts diffused hydrogen gas, which is absorbed by the electrode material. The metal-oxide-based cathode stores oxygen. Electric current flows between the two through an electrolyte. With an excess of oxygen in the cathode and an excess of hydrogen in the anode, the cell can function without additional oxygen or hydrogen fuel at 50% peak current for eleven minutes, or at full power for five minutes.
Corrigan says the Ovonics metal-hydride fuel cell has a start-up time “in micro-seconds,” operates well at low temperatures, and has a long life expectancy. Among the technology’s advantages is the comparative low cost of the components used in the metal-hydride cells, which are far less expensive than the platinum catalysts, exotic ion exchange membranes and specially machined graphite bipolar plates used in PEM technology.
“Instead of using the platinum, we’re using base metals,” says Corrigan. The fabrication is fairly simple, with known processes and equipment that have been around for hundreds of years. So the manufacturing is also cheaper. “We’re really talking about a different order of magnitude of cost.”
Corrigan adds that unlike PEM cells, the metal-hydride fuel cell can “run backwards,” meaning it can accept a charge, at about 80% efficiency, from such sources as solar-powered PV arrays and devices that capture the mechanical energy from a vehicle’s braking system.
But PEM technology is currently far more widely available and, for the time being, cheaper. The nickel-hydride technology is still “fairly immature,” says Corrigan. Early prototypes now generate about 70 W/kg while fully developed PEM fuel cells can do 1kW/kg. PEM fuel cells now deliver about 1 A/cm2 while the metal-hydride fuel cell prototypes can deliver about 250 mA/cm2. ‘We are now doing the engineering work to close the gap in power performance,’ says Corrigan.
But the current status of metal-hydride fuel cells may be reminiscent of the metal-hydride battery just a few years ago, when it was considered marginal at best. Now it’s a billion-dollar player at the heart of the hybrid auto industry.
So as an interim strategy, Ovonics is focussing on steady-state emplacements for its fuel cells, including uses in military systems, cell towers and as Uninterrupted Power Supply (UPS) backups for computer data centers. “We’ve seen fuel cells on space ships and on breathalyzers,” says Corrigan. “The metal-hydride technology can become far more efficient, and when it does, it could change a lot of things.
“Nothing beats actually having a real product in the field and getting the feedback in terms of making an impact, and at ECD our objective is to make an impact, not just to be a science lab,” he adds.
ECD is also, clearly, at the vanguard of helping to put the world on a renewable-energy footing, with ever-advancing IT capabilities. “With Stan Ovshinsky’s insights,” Corrigan says, “we’ve seen a lot of things that didn’t seem possible turn out to be true.”
Harvey Wasserman is a US-based energy writer. e-mail: email@example.com
Harvey Wasserman is also author of SOLARTOPIA! OUR GREEN-POWERED EARTH, A.D.2030, available via www.solartopia.org.
Stan and Iris Ovshinsky, pioneers of amorphous/disordered material world
Married for more than a half-century, Stanford and Iris Ovshinsky are certain to be remembered as one of the most important couples in scientific, engineering and environmental history. Sadly, in late 2006, Iris suddenly and unexpectedly passed away, leaving the renewable energy world shaken and saddened.
Honoured in 2000 with a ‘Heroes of Chemistry Award’ from the American Chemical Society for their ‘significant and lasting contributions to global human welfare,’ the Ovshinskys’ joint talents and entrepreneurial drive have combined to re-define and in many ways to actually invent the art and science of both digital computing and renewable energy.
|Iris Ovshinsky, sadly missed.|
The Ovshinskys shared an ardent commitment to peace, social justice and environmental preservation. Referring to himself as a CEO who was also, uniquely, a member of a trade union, Stan proclaimed himself to be ‘prouder of the organization and working climate that we have built than any of my inventions.’
In 1955 the couple sailed into the uncharted waters of disordered and amorphous solids. As one biographer puts it, ‘using the periodic table as their nautical chart and their physical intuition as their compass,’ they had the field virtually to themselves.
As early as the 1960s, far in advance of all but a very few futurists, they predicted that renewable energy would be essential to human survival. In 1999 Stan was named a ‘Hero for the Planet’ by Time Magazine, an award he readily acknowledged also belonged to Iris. He also received the Karl Boer Solar Energy Medal of Merit, awarded jointly by the University of Delaware and the International Solar Energy Society.
The couple’s five children include Robin, a physician in New York City; Steven, a professional musician with the San Francisco Symphony; Dale, who works in a Publix in Florida; and Harvey, a noted newspaper publisher and documentary filmmaker, living in Ann Arbor, about fifty miles (80 km) from ECD headquarters. Ben, the eldest son, is ECD’s West Coast Representative.
Throughout their careers, Stan and Iris were inseparable, appearing at conferences and working together on a daily basis, explaining that they simply enjoyed each other’s company.