Geography 3422A/B : Direct Current Gets Another Look.docx
23 Oct 2012
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Thomas edison and his direct current, or dc, technology lost the so-called war of the currents to alternating current, or ac, in the. 1890s after it became clear that ac was far more efficient at transmitting electricity over long distances. Alstom, abb, siemens and other conglomerates are erecting high- voltage dc grids to carry gigawatts of electricity from wind farms in remote places like western china and the north sea to faraway cities. Companies like sap and facebook that operate huge data centers are using more dc to reduce waste heat. Panasonic is even talking about building eco-friendly homes that use direct current. The ac forces won when tesla and westinghouse figured out how to fine-tune ac transmission so that it required far fewer power plants and copper cable. At&t adopted direct current for the phone system because of its inherent stability, which is part of the reason that landline phones often survive storms better than the electric grid.
