Fuel cell technology benefits and applications for micro- and nanotech commercialization
12/01/2008
By Peter Podesser, SFC Smart Fuel Cell AG
Fuel cells have long been hailed as an environmentally friendly, silent, and efficient energy source for powering a diverse number of applications off the grid. While many fuel cell technologies are still in prototype testing, mobile and portable direct methanol fuel cells (DMFC) already demonstrate that they can solve a wide range of energy supply problems that industrial and government operators of remote systems face everyday.
Before the advent of fuel cells it was nearly impossible to power remote devices reliably around the clock, seven days a week. Batteries died quickly, solar cells were too unreliable in bad weather, and generators were noisy, required high maintenance, and were banned in many places for environmental reasons. Consequently, operators often had to commit personnel, equipment, and logistic resources to ensure 24/7 operation of their off-grid devices. In some cases this meant flying out fresh batteries by helicopter twice a week; in other cases, such as in national parks and reserves, teams of rangers would have to hike for days with heavy batteries in their backpacks to especially remote sites where sensors, measuring units, or cameras operated. Where generators were the primary power source, trucking in maintenance supplies and fuel was labor-intensive and costly, apart from the fact that generators are noisy and produce noxious exhausts. Moreover, each of these systems had a heightened risk of discovery during battery replacement or refuelling, which increased the possibility of sabotage, theft, and vandalism.
DMFCs are a cost-effective, clean, and safe alternative wherever off-grid and reliable power availability is required. They use liquid alcohol methanol, a fuel with a very high energy density, to produce power. Ten liters contain a capacity of over 11kWh at a mere weight of 8.4kg, enabling operators to keep a large storage of energy at the site without minimal logistic and maintenance effort–the same amount of energy stored in a battery would weigh 279kg, and 10 liters of methanol can power a 10W device continuously for six weeks maintenance-free.
Intelligent power concept
The EFOY (“Energy For You”) fuel cell, developed by Smart Fuel Cell, is an intelligent energy source. In combination with a standard battery-powered system or a solar-powered system, the fuel cell’s integrated charge control constantly monitors the charge level of the battery. Whenever this drops below a pre-defined level, the DMFC automatically starts operation and recharges the battery. Once the battery is full again, the fuel cell returns to standby mode. Worry-free remote monitoring provides assurance that the fuel cell is doing its job, even when the operator is miles away. Since it can charge standard batteries directly, it easily integrates into existing facilities. Operation is intuitive, either on site directly or remotely, by means of a GSM modem.
DMFCs generate electricity completely independent of the environment. They will produce power continuously as long as there is fuel. If necessary, they can work 24 hours a day at temperatures ranging from -20°C to 45°C. The fuel cell itself remains maintenance-free throughout its entire life; the only maintenance required is infrequent fuel cartridge replacement.
Environmentally friendly power and proven safety
Power generation in a DMFC produces only carbon dioxide and water vapor, in amounts comparable to a child’s breath. The fuel cells thus meet the strictest environmental regulations.
These fuel cells and cartridges also conform to the highest international safety standards. They have received numerous certifications, such as the TUEV GS seal, the TUEV SUED, Octagon Quality Seal “Tested fuel cell system” by Germany’s TUEV SUED Industry Service GmbH (the EU’s counterpart of Underwriter Laboratories Inc.), and the cNRTLus approval on the EFOY fuel cells, which certifies the products’ compliance with recognized UL safety standards. Every EFOY product is authorized for transport by land, sea, or air.
Paving the way toward micro/nano applications
While miniaturized fuel cells as part of mobile phones or laptops are still in the experimental phase, EFOY fuel cells are evolving toward smaller and portable form factors. The portable Jenny fuel cell, which is being used and tested by defense organizations in the US and Europe, weighs only 1.3kg and is about the size of a quart of milk. Very quiet in operation, orientation-independent, and small enough to be worn in a jacket or a backpack, it provides 25W nominal power to a battery. While the system is currently used only in defense applications, the technology could also be used to produce portable charge stations that power a wide range of portable systems such as mobile phones, PDAs, laptops, and GPS systems. With an SFC power management system, the charge station would be able to automatically recognize the voltage demands of the individual devices and adapt the output power accordingly.
Dr. Peter Podesser is CEO of Germany fuel-cell developer Smart Fuel Cell AG. He also was a co-author of the first edition of MANCEF’s (Micro- and Nanotechnology Commercialization Education Foundation) International Micro/Nano Roadmap.
How DMFC fuel cells work
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The EFOY fuel cell transforms chemical energy directly into electrical energy. The transformation is highly efficient and involves no moving parts, making it a particularly effective source of power.
 Diagram of a direct-methanol fuel cell |
At the heart of every EFOY fuel cell is the stack. The stack actually consists of several cells: an anode, a cathode and a membrane that acts as an electrolyte, separating the anode and the cathode from each other. Methanol and water are introduced on the anode side while ambient oxygen enters the cathode side. Protons (positively charged H+ ions), free electrons, and carbon dioxide arise on the anode side. While the protons can permeate the membrane, the electrons have to travel an electrical circuit over to the cathode side, thereby producing electrical current. H+ ions and oxygen form water vapor on the cathode side, making EFOY fuel cells an extremely environmentally friendly way to generate electricity.