Resource World Magazine

j u n e / j u l y 2 0 1 5 www.resourceworld.com 59 be happier than Natcore's shareholders. The Natcore team provided background information for this article. For more information, see Natcore's web site at nat- coresolar.com. departMent Of energy annOunCes wave energy prize COMpetitiOn The US Department of Energy (DOE) announced on April 27, 2015, its latest competition, with a prize purse totaling more than $2 million, available for top ranking teams. The prize encourages game- changing wave energy conversion (WEC) devices that double the energy captured from ocean waves and reduce the cost of wave energy, making it more competitive with traditional energy solutions. The 20-month design-build-test com- petition offers participants seed money and a chance to take part in two rounds of testing, the second being an opportu- nity to test their scaled WEC prototypes at the nation's most advanced wave-making facility, the Naval Surface Warfare Center's Maneuvering and Seakeeping (MASK) Basin at Carderock, Md., beginning in the summer of 2016. new aLuMinuM-iOn Battery COuLd repLaCe Many LitHiuM-iOn and aLkaLine Batteries In California, Stanford University's news- letter reports that its scientists have invented the first high-performance aluminum battery that's fast-charging, long-lasting and inexpensive. Researchers say the new technology offers a safe alter- native to many commercial batteries. Aluminum has long been an attractive material for batteries, because of its low cost, low flammability and high-charge storage capacity. For decades, research- ers have tried unsuccessfully to develop a commercially viable aluminum-ion bat- tery. A key challenge has been finding materials capable of producing sufficient voltage after repeated cycles of charging and discharging. An aluminum-ion battery consists of two electrodes: a negatively charged anode made of aluminum and a positively charged cathode. "People have tried dif- ferent kinds of materials for the cathode," Hongjie Dia, Professor of Chemistry said. "We accidentally discovered that a simple solution is to use graphite, which is basi- cally carbon." For the experimental battery, the Stanford team placed the aluminum anode and graphite cathode, along with an ionic liquid electrolyte, inside a flexible polymer-coated pouch. "The electrolyte is basically a salt that's liquid at room tem- perature, so it's very safe," said Stanford graduate student Ming Gong. The Stanford team reported "unprec- edented charging times" of as little as one minute with the aluminum prototype, and the Stanford battery withstood more than 7,500 cycles without any loss of capac- ity. "This was the first time an ultra-fast aluminum-ion battery was constructed with stability over thousands of cycles," the authors wrote. By comparison, a typical lithium-ion battery lasts about 1,000 cycles. "Another feature of the aluminum bat- tery is flexibility," Gong said. "You can bend it and fold it, so it has the potential for use in flexible electronic devices. Aluminum is also a cheaper metal than lithium." In addi- tion to small electronic devices, aluminum batteries could be used to store renewable energy on the electrical grid. The battery produces about half the voltage of a typical lithium battery, but improving the cathode material could eventually increase the voltage and energy density. uk gets first Battery-pOwered train passenger serviCe in Over HaLf a Century Bombardier Transportation [BBD-TSX], headquartered in Montreal, Canada has demonstrated its battery-powered train, known as the Independently Powered Electric Multiple Unit (IPEMU), which can be driven entirely by battery technology in addition to drawing power from its pan- tograph (an apparatus mounted on the roof of an electric train, tram or electric bus to collect power through contact with an overhead catenary wire). The train is part of a research program partly funded by Network Rail and the Rail Executive arm of the Canadian Department for Transport. Working with industry stakehold- ers during a seven-month design phase, Bombardier reconfigured an ELECTROSTAR Class 379 train to enable installing and integrating an operational traction battery system. The alteration required engineers to modify the carriage creating the necessary space in the under frame to accommodate the lithium iron magnesium battery cells. Engineers also added high voltage and communications cabling, standard safety features and battery controls as well they integrated the traction and train control management systems. The new design uses existing line converter equipment to charge the batteries and connects the motor converters to the batteries when the 25 kVAC overhead line is not available. In addition to low noise and reduced energy consumption, battery operation's main benefit is that it enables the train to cross non-electrified lines and allow it to be used in the event of an electrical fail- ure without using overhead wire systems or diesel power. Branch lines can also be used where it is not cost-effective to install additional overhead electrification as well as expanding rolling stock capacity by increasing the flexibility of existing diesel powered trains. After a phased approval process and dynamic track testing, the train entered passenger service in January 2015 as part of a trial. n

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