Resource World Magazine

without a continuous supply of electricity. Impact: The warmers distributed with 11 partnerships in eight countries may impact thousands of babies. Flextronics Economic Development Award Grameen Foundation USA Region of Impact: Uganda��� Problem: Lack of agricultural information among the poorest and hardest-to-reach rural farmers. Solution: A social enterprise scheme with 800 community knowledge workers (CKWs) who use smartphone-based knowledge to share expert agriculture information with small farmers and collect data through mobile surveys. Impact: 17% increase in knowledge of six representative agriculture practices, 37% difference in higher maize prices versus non-CKW-served farmers, and 51% difference in ���access to extension services and training��� versus non-CKW-served farmers. Accenture Sustainable Energy Award Simpa Networks Region of Impact: India Problem: 400 million people in India, and more than 1.5 billion people worldwide, are without access to reliable electricity. Solution: Simple, affordable, pay-asyou-use pricing and mobile payment for off-grid solar energy solutions. Impact: By 2015, more than 250,000 households with access to clean energy, 6.5 megawatts of distributed solar power installed, and more than 160,000 tonnes of CO2 displaced. Eco-Fuel Africa Region of Impact: Africa��� Problem: Clean cooking fuel is inaccessible for 30 million people in Uganda and 28 million poor farmers have no access to fertilizers. Solution: Simple, locally made technolMARCH 2013 ogy that can be used by local people to convert locally sourced farm and municipal waste into clean cooking fuel and organic fertilizers. Impact: 6,000 families already benefiting from the technology, with 10,000 more expected to be reached by the end of 2013. SCIENTISTS LOOK TO IMPROVE POLYMERBASED SOLAR CELL PRODUCTION North Carolina State physicist, Harald Ade, and his group, working with teams of scientists from the United Kingdom, Australia, and China are examining the physical structure of polymer-based solar cells and looking for ways to improve their production. Polymer-based solar cells comprise two domains, known as the acceptor and the donor layers. Excitons, the energy particles created by solar cells, must be able to travel quickly to the interface of the donor and acceptor domains to be harnessed as an energy source. Researchers had believed that keeping the donor and acceptor layers as pure as possible was the best way to ensure that the excitons could travel unimpeded, so that solar cells could capture the maximum amount of energy. According to Ade, ���We had previously found that the domains in these solar cells weren���t pure. So we looked at how additives affected the production of these cells. When you manufacture the cell, the relative rate of evaporation of the solvents and additives determines how the active layer forms and the donor and acceptor mix. Ideally, you want the solvent to evaporate slowly enough so that the materials have time to separate ��� otherwise the layers ���gum up��� and lower the cell���s efficiency. We utilized an additive that slowed evaporation. This controlled the mixing and domain size of the active layer, and the portions that mixed were small.��� The efficiency of those mixed layers was excellent, leading to speculation that perhaps some mixing of the donor and acceptor isn���t a problem, as long as the domains are small. ���We���re looking for the perfect mix here, both in terms of the solvents and additives we might use to manufacture polymer-based solar cells, and in terms of the physical mixing of the domains and how that may affect efficiency,��� Ade says. The research was funded by the US Department of Energy. RESEARCHERS EXPLORE USING SOLAR WIND TO PROPEL FUTURE SPACECRAFT Electric solar sails, or ESAILs, provide propulsion for spacecraft by using solar wind, not fuel. The technology, which works by creating an electric field that deflects solar wind protons and takes momentum from them, offers the future possibility of fast, cheap, and fuel-less travel throughout the solar system, and perhaps an economically viable way to extract resources from asteroids. Researchers at the University of Helsinki have succeeded in creating a 1-kilometre-long ESAIL tether, featuring 90,000 ultrasonic welds. An electric sail consists many long (as long as 20 km), very thin conducting tethers (wires). An Estonian ESTCube-1 satellite launching in March will first test a 15-metre-long tether, followed by a test of a 100-metre-long tether in 2014. Development of this technology will eventually allow for the cheap, large-scale gathering of the abundant resources available in space, primarily those available in asteroids and comets. The gold, cobalt, iron, manganese, molybdenum, nickel, osmium, palladium, platinum, rhenium, rhodium, ruthenium, and tungsten that we mine from the Earth���s crust were deposited by asteroid impacts after the crust on the planet cooled The ESAIL also will allow the large-scale, space mining of resources like water, oxygen, hydrogen, and construction metals to supply space projects. n www.resourceworld.com 51

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