Fuel cells slated to energize plastics demand

Few technologies offer as much promise for processors as fuel cells says Jens Müller, head of development at Smart Fuel Cell. He predicts that applications for laptops, camcorders, robots, and measurement instruments represent potential sales ranging to several million euros annually.

The units combine fuel and air to directly convert these to electricity, heat, and water. Thermoplastic components (membranes, bipolar plates, monopolar stacks, end plates, assemblies, and manifolds) should represent big future business for processors. Fuel cells with polystyrene sulfonate-based membranes were used by astronauts in NASA''s Gemini program 40 years ago, but they lacked durability and longevity, and were too expensive. Development today concentrates on squeezing costs and improving power output. "Admittedly, the route from prototype to product is often long and more strewn with obstacles than the conversion of the original idea into a prototype," Smart Fuel Cell''s (SFC; Brunnthal-Nord, Germany) Müller says.

Tokyo''s Fuel Cell Expo, held in January, saw packed aisles and high interest. Most technology, however, remains in the development phase. Manfred Stefener, SFC executive director, says his company was the only exhibitor able to present a commercial fuel cell product with its SFC A50 fuel cell for sailing vessels and recreational vehicles.

SFC''s units produce electricity from liquid methanol rather than hydrogen, which requires pressurized tanks. The methanol is stored in portable, blowmolded HDPE containers, and the company''s new MFC-100 fuel cell has enough fuel for more than 400 ampere-hours of electricity. Its 4.3-kg blowmolded jerrycan of liquid methanol provides energy comparable to that provided by batteries weighing more than 100 kg. SFC works with partners Mitsui (Tokyo) and DuPont (Wilmington, DE).

DuPont Fluoroproducts (Fayetteville, NC) says it has more than 30 years of fuel cell system development experience. One of its key elements is the film for membrane-electrode assemblies (MEA) in fuel cells. Depending on the grade, DuPont dispersion-casts or extrudes its Nafion-brand membranes of perfluorosulfonic acid polymer/polytetrafluoroethylene (PTFE) copolymer. For example, its NRE-211 and 212 films, in thicknesses of 25 to 51 µm, function to selectively transport positively charged ions across the cell junction in a Proton Exchange Membrane (PEM) fuel cell.

"Everywhere around the world companies are working on fuel cell improvements," says Christian Collette at competitor Arkema (Paris). His company is developing a new proton exchange membrane, still in the R&D stage, based on its Kynar-brand polyvinylidene fluoride (PVdF). "Today, sulfonated perfluoropolymer membranes are often used for this application, but our solution should allow better economics," Collette says.

Arkema''s first developments, partly financed by the U.S. Dept. of Energy, are expected to be in stationary applications and also in direct methanol fuel cells for portable devices. "A significant development in the automotive sector is not expected before 2015," he says.

Gore Fuel Cell Technologies (Elkton, MD) has concentrated its work on using reinforced PTFE/fluoroionomer composite membranes, which it says allow a dimensionally more stable membrane in the X-Y plane for more strength, elimination of external humidification, and the ability to deliver maximum power density while helping minimize costs.

But not everyone agrees that fluoropolymers provide the answer. A membrane engineering company, PolyFuel (Mount View, CA), a Stanford University Research Institute spinoff, believes better membranes for methanol-based fuel cells can be processed using cheaper "hydrocarbon-based [polymers] and sulfonate groups for the conductive elements." Although PolyFuel president Jim Balcom refuses to divulge the membrane''s chemical makeup, one sector observer speculates it is based on ultrahigh-molecular-weight polyethylene.

One of the problems faced with methanol fuel cells has been where the catalyst is introduced and the methanol breaks down into CO2 protons and electrons. Some of these reconnect to produce surplus water. Also, when high concentrations of methanol are used, it sometimes crosses over or leaks through the film to the air side, creating excess heat and water, thereby reducing efficiency. PolyFuel feels it has found a solution to the problem.

Balcom says fluoropolymer-based membranes typically require high levels of moisture for stable operation, whereas his operate well at low relative humidity. "This means the fuel cell or automotive manufacturer does not have to add overly complicated and expensive systems to keep the membrane hydrated," he says. "Additionally, hydrocarbon membranes retain stability at an operating temperature of 95ºC, which reduces engine cooling system complexities." He says his membranes produce up to 15% more power in real-world conditions compared to perfluorinated membranes.

PolyFuel produces its membranes via solution casting, a method using temporary carriers such as endless belts or rolls followed by solidification. Test marketing of its membranes for portable applications should happen this year, with commercial launches in 2007. "Opportunities for plastics processors as this market develops will include materials and components for the fuel cell and the methanol fuel cartridge," he says. BC

Solar power is back with plastics'' help: But did it ever leave?

Solar power as a primary means of providing energy for homes has had its ups and downs since the 1980s, when government incentives for installing solar made it popular among home-owners looking to reduce electric bills.

Challenges had to be overcome. Silicon-based solar cells were expensive to manufacture and installation was difficult. Additionally, they converted a very low percentage (just 12% to 15%) of the sun''s rays into electricity, noted an article titled "Plastic Power" in the June issue of Business 2.0. This is why, the article claims, "it costs 22 cents to produce a kilowatt-hour of electricity using today''s solar technology compared with 4 cents at a coal-fired plant." Silicon-based technologies currently have 98% to 99% of the industry, according to industry experts.

Jigar Shah, CEO of SunEdison LLC (Arlington, VA), says the worldwide market for photovoltaic (PV) products is increasing by 30% annually. However, over the last 10 years the U.S. market for PV products has been steadily shrinking from 50% of the worldwide market to less than 15%. Speaking in the Nov. 8, 2004 issue of Solar Flare, a quarterly publication covering the PV industry from Strategies Unlimited, Shah notes that "professionals and observers attribute strong worldwide growth to consistent government support in the two big worldwide markets-Germany and Japan," two nations that boast "broad public support and immense political momentum."

However, things may be changing. With oil prices topping $50/barrel, there''s been a renewed interest in solar energy with the development of next-generation technology that promises to make solar power competitive and cost effective to manufacture and install. The new photovoltaics use tiny solar cells embedded in thin sheets of plastic to create an energy-producing material that is cheap, efficient, and versatile.

A major contributor to the resurgence of solar power is Siemens Corp., which has developed technology that melds nanoscale buckminsterfullerene molecules with conductive plastic polymers. In September 2004, Konarka Technologies Inc. (Lowell, MA), an innovator in developing and manufacturing breakthrough products that convert light to energy, announced the acquisition of Siemens AG''s organic photovoltaic research activities. Dr. Christopher Brabec, a polymer scientist who led Siemens'' solar efforts, became Konarka''s director of polymer photovoltaic research.

Product vs. technology

This acquisition brought together two leading efforts to develop and commercialize a new generation of photovoltaics. These new plastic power cells will make it possible for any electronic device, such as a mobile phone or laptop computer, to carry its own onboard source of renewable energy, says Daniel McGahn, executive VP for Konarka.

Up to this point, Konarka and Siemens had been working independently to harness breakthroughs in materials science and nanotechnology to create efficient, lightweight, and flexible polymer-based electronics. Unlike traditional PV cells made of silicon that tend to be bulky, protruding structures encased in glass and expensive to make, Konarka''s plastic solar cells use a manufacturing process similar to photographic film, and cost about one-third as much to produce for the same amount of power.

McGahn, who is in charge of commercializing Konarka''s technology, notes that using plastics, such as a form of PE as a substrate, layered with a polymer-based coating in a roll-to-roll machine, makes mass commercialization possible. "What we can do in one step takes others many steps to achieve," says McGahn. "Ours takes a roll of plastic, runs it through the coating machine, and it comes out an engineered material, with wiring and flexible electronics all built in."

That is what separates Konarka from its competitors, notes McGahn. Originally spun out of the Univ. of Massachusetts, Lowell, Konarka''s business model is much different. "Our product will be sold to others to enhance their products," McGahn explains. "One of the stumbling blocks to mass commercialization of solar is that manufacturers have to develop their own sales, distribution, and service infrastructure. We''re thinking like a chemical company would rather than a typical solar company. The difference between Konarka and the big guys such as Sharp, BP Solar, and Shell, when you look at it from a cost or distribution standpoint, is about getting the product to where it will be consumed. It''s all about materials and manufacturing."

Konarka is focused on product development, not technology development, McGahn says. "We''re trying to deliver it in a form people can buy, through roofing-materials suppliers, for example," he states. "We want to convert existing roofing materials into photovoltaic product. We can take different polymers and create different patterns to create roofing materials that look like your current roof. You can create whatever your HOA [homeowner association] approves, giving you the benefits of solar without the traditional downsides."

Solar today is an estimated $5 billion market, and is growing about 40% year-to-year. It''s projected to have grown 47% in 2004, and 35% to 40% through the next decade, across all applications. Off-grid growth is estimated at about 16%, while on-grid growth is about 80%, with grid-connected PV driving the market. Those in the solar-energy market segment are excited about its long-term prospects.

"We''re talking strong, consistent growth that any industry would be glad to see," McGahn states, adding that the industry needs to move forward with thinner, flexible technology with good energy performance.

In addition to Konarka, two other players in this game are Nanosys Inc. and Nanosolar Inc. (both Palo Alto, CA), which have jumped into thin-film solar cell technology. One of Nanosys''s products is a new type of solar cell that performs like a traditional solar cell, but can be configured like a lightweight, flexible plastic. In particular, this technology has the potential to provide low-cost solar power through currently available high-volume, inexpensive manufacturing techniques based on conventional film-based processes such as roll-to-roll manufacturing. "To develop our nanotechnology-enabled solar cells, we are collaborating with Matsushita and several U.S. government agencies," notes the company.

Nanosolar has developed a new class of solar electric cells based on the economies of printing, and offers its SolarPly, a trademarked product that is lightweight for easy installation on almost any roof type without structural enhancements. The 10-by-14-foot sheet produces 110V.

The big players

However, it''s pointed out by Solarbuzz, a solar energy consulting and research firm based in San Francisco, in its online report, that Konarka will be the company to watch even though the gorillas of the industry-Shell, Kyocera, Sharp, and BP-account for more than half of solar cell production worldwide. That''s not to say that some of those companies aren''t making headway.

In August 2004, Kyocera announced it will begin large-scale assembly of solar PV modules at it maquiladora in Tijuana, Mexico, with plans to establish a regional office in San Diego for solar system engineering and marketing. Kyocera''s PV modules offer an environmentally friendly renewable-energy solution by converting sunlight into electricity with no moving parts or emissions. The Tijuana facility will produce state-of-the-art PV modules ranging from 35 to 190W, with a planned production capacity of 35 mW per year. This facility will eventually produce all of the PV modules that Kyocera sells in the Americas.

"The partnership between Kyocera''s global solar group and our Tijuana maquiladora operations will help to make clean, reliable solar energy systems more widely available for business and homeowners throughout the Americas," says Rodney N. Lanthorne, director of Kyocera Corp. and president of Kyocera International Inc. "This expansion reflects both the growing demand for solar energy systems and the success of our Mexican operations in providing high-quality, cost-effective manufacturing."

General Electric is another big player, adapting organic light-emitting diodes for use as light collectors in plastic solar cells. Katharine Brass, spokesperson for GE Energy (Atlanta, GA), says that it is something of a misconception to speak of solar technology making a comeback. In fact, she says, "The solar industry has been growing for the last several years at an annual rate of approximately 30%."

Brass notes that large segments of the industry, such as the grid-connected segment, have reached compound annual growth rates exceeding 50% over the same period. GE has thoroughly studied this industry and concludes that solar technology has a very bright future. "It is a logical part of the portfolio of renewable energy technologies that GE has assembled," Brass explains. "Since GE has a highly advanced plastics capability, the evaluation of advanced plastics technology is a significant part of the solar research efforts at GE. This in turn is part of a comprehensive effort on the part of the company to bring down the cost of all aspects of solar energy technology installation cost."

In the real world

A GE Energy press release from Oct. 21, 2004 claims that GE''s solar electric equipment and customer service have quickly become the standard for many top U.S. homebuilders looking to meet the growing demand for energy-efficient, attractive homes. The company''s roof-integrated solar electric systems are in particularly high demand, as they blend seamlessly with the roofline, providing homeowners a unique combination of functionality, attractiveness, and increased property value.

The release points to one of the country''s most prominent solar housing projects, located in Ladera Ranch, an 8100-home development in southern Orange County, CA. Ladera Ranch consists of six villages, including the 1260-home Terramor Village. More than 75% of the homes sited for solar at Terramor will feature GE solar equipment, making it the nation''s largest solar-powered community when it is finished in 2005.

California would seem a logical place for solar use to thrive, given the energy issues key to many a political battle over the past several years. An article in the Oct. 10, 2004 edition of The San Diego Union-Tribune notes that "trend-setting" builders are offering buyers houses that use solar technology that generates enough electricity to meet half or more of a home''s needs. Gov. Arnold Schwarzenegger has made solar energy "a key plank of his legislative agenda," but a comprehensive bill failed in the final days of the legislative session. Gov. Schwarzenegger signed instead a stopgap measure to continue funding of solar rebates for homeowners who install the technology to reduce dependence on the grid.

Already one homebuilder in San Diego County has a new-home development in Carmel Valley, called Soleil, that uses solar energy. The development is the first in San Diego County to earn the Dept. of Energy''s Zero Energy Home designation for maximizing energy efficiency, according to the same article.

The first multiregional homebuilder to make a 100% commitment to EnergyStar, Pardee Homes, has partnered with GE on energy-saving efforts for years, most recently with GE Energy''s roof-integrated solar technology for Evergreen-a Terramor Village neighborhood at Ladera Ranch-as well as for San Diego''s Soleil. "Our goal is to marry the benefits of energy savings and resource conservation with the architectural quality and design livability today''s buyers expect in a new home," said Pardee''s Joyce Mason, VP of marketing. "GE has contributed significantly to our LivingSmart programs, which will account for nearly 2400 new homes across our markets by the end of 2006."

GE Energy''s current range of solar energy products includes solar cells, modules, and pre-packaged systems. The modules range from 35 to 165W, while system designs can range from hundreds of watts to megawatts and can be used in either on-grid or off-grid applications. Brass notes that while they don''t play a huge role in solar right now, "plastics is where it''s going," and how fast depends on finding materials that don''t degrade under extreme weather conditions. "The whole solar industry is focused on plastics and how it can play a role, and obviously, given GE''s position in the plastics industry, it''s a critical component for us," Bass concludes. CG

Takeoff for turbines?

If a research team at MIT has its way, the turbines that lift the heft of a jetliner or power entire metropolitan areas could be coming to your laptop, with plastics playing an integral role as a heat sink and insulator for internal gas temperatures that reach 1500ºC.

Under a $5-million grant initially supplied in 1994 from the U.S. Army Research Office and the Defense Advanced Research Projects Agency (DARPA), the gas turbine lab at MIT has been at work developing a microturbine roughly the size of a button that it hopes will offer 20 times the energy of a chemical battery.

"If you want efficient power," explains Mark Spearing, a materials engineer working on the project, "it''s very hard to beat a jet engine. It''s the most efficient way of converting chemical energy to mechanical or electrical energy there is. The trick is to go smaller."

Using silicon carbide, the turbine''s components are fabricated at a micro level with lithography and etching processes found in chip making, with tolerances between 100 nanometers and 1 µm. The turbine''s combustor is about .5 cu cm in size, consisting of three silicon wafers stacked together. Right now, the turbines are burning hydrogen (eventually the goal is to use a hydrocarbon like propane) with a flame temperature around 1500ºC, spinning the blade at 2.5 million revolutions/min. If the turbines are proved out within the year, which is the goal, Spearing estimates commercial development will occur within five years.

But before your next notebook is powered by a turbine, MIT''s immediate target under the DARPA sponsorship is to replace the BA 5590 lithium chemistry batteries that power portable equipment like radios, battlefield computers, night sights, and GPS navigation systems.

Those chemical batteries weigh roughly 1 kg and consume a liter in volume, but although the turbines themselves are much smaller, once they''re enclosed in their housing and manifold, the whole system will be approximately the same size and weight. The difference, however, is that they''ll provide 20 times the energy, so a mission could last 20 times longer without any additional weight burden.

The housing''s size is currently necessary to supply air intake for combustion and act as a heat insulator, dissipating thermal energy. "Our intention is to keep the exterior package temperature to something like you''d get on the outside of a piece of electronics hardware at the moment," Spearing says. He thinks the heat sink might approach 100ºC, but not eclipse that level.

As they do in current battery-operated electronics, plastics will serve to reduce weight and dissipate heat, but those aspects take on life-or-death importance to a soldier in the field already weighed down with 50-plus lb of gear; and with widespread use of infrared technology, any heat signature from the turbine''s exhaust is verboten. "Infrared cameras are everywhere," Spearing says, "so if you have something that''s really hot, it shines pretty brightly. Even several tens of degree Celsius, you get spotted quickly."

The entire project falls under the auspices of the Department of Defense''s (DOD) science and technology program, which Ronald Sega, director of defense research and engineering, outlined last March before the U.S. House Armed Services Committee. Energy and power technologies are among three initiatives to be funded with $10.5 billion in fiscal 2005. The goal is a wired soldier, making notebooks and other information technology devices as ubiquitous in the field as a rifle. To realize it, heavy chemical batteries with only four or five hours of life must be replaced. "This initiative is investing in technology that could develop batteries with over five times the energy density," Sega testified.

In addition to the turbines, the power push also includes fuel cells, with the Marines already field-testing 12V fuel cells, called personal power systems, which replaced $8000 in traditional batteries with $250 in hydrogen.

Fuel cells seem to be the obvious competition for the turbines, especially in terms of "greenness," promising oxygen and water as the only emissions, but Spearing says a broader view of energy is needed. Sustainability could come from greater efficiency, not just renewable or alternative fuel sources.

"People have quite highly vested interests in any of these [energy technologies]," Spearing admits, "and I''m no different. But I think it''s time for some more careful accounting of what''s clean and what''s not." TD

Nano goes solar

BP Solar, a leading manufacturer of solar-electric products, has contracted with the Rochester Institute of Technology''s (RIT) NanoPower Research Laboratories to develop plastic solar cells using nanomaterials. Total funding for the three-year research program is $250,000, according to an announcement from RIT.

Until now, lightweight plastic solar cells have remained out of reach as scientists struggled to substitute polymers for expensive, but effective, cyrstalline materials such as silicon, a traditional solar cell material. The attempts produced solar cells that were inefficient converting light to electricity.

RIT researchers, led by Ryne Raffaelle, professor of physics and microsystems engineering and director of the NanoPower Research Laboratories, hope to develop an improved polymer solar cell using nanomaterial additives. Raffaelle and his team at RIT will use a thin polymer film that can be rolled out in sheets. The film will contain nanoscale pieces of semiconductor material and single-walled carbon nanotubes to maximize energy conversion.

"Nanotechnology, and more specifically nanomaterials, may provide breakthroughs in the way we convert and use readily available energy sources," Raffaelle says.

RIT established the NanoPower Research Laboratories in 2001 as a series of four labs specializing in power devices and nanomaterials. In addition to a staff of research scientists, 15 undergraduate and graduate students work in the labs, gaining hands-on experience in cutting-edge technical research.

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