Thomas Edison and his Direct Current “DC” technology lost the historical so-called “War of the Currents” to Alternating Current “AC” in the 1890s that was championed by the Edison rivals Nikola Tesla and George Westinghouse. The argument was AC was far more efficient at transmitting electricity over long distances.

Edison, inventor of light bulb and the world’s first DC power distribution system in 1882 was not totally wrong to insist on the needs for DC distribution grid. The technological advantages of AC over DC at that time dedicated the success and expansion of AC power distribution grids initially developed in 1886 by Westinghouse and Stanley with major inputs from Nikola Tesla. An AC power system allowed voltages to be “stepped up” by a transformer for distribution, thus reducing power losses, and then “stepped down” by a transformer for consumer use. The AC technology became gradually mature for large-scale grid up-scaling. However, the advances of DC power distribution for long-distance power transmission took a revival in 1954 when the Swedish company ASEA, predecessor of ABB, the Swiss maker of power and automation equipment, linked the island of Gotland to mainland Sweden with high-voltage DC lines.

However, by late 19th century science and technology was too blind to recognize the problems associated with the use of fossil fuel, e.g. coal, oil and gas, for production and distribution of electric power. During the 20th century it has been an accelerating pile-up of threats not only from fossil fuel consumption what regards the green-house impacts on climate, but also the associated impacts on water resources from fossil fuel production in form of enormous and irreversible environmental pollution and degradation of ecological and water qualities.  With birth of renewables, e.g. solar, wind, geothermal, hydropower and wave power, and the continuous advances in associated DC and smart technologies the advantages of DC distribution grids became once more apparent. They are economic for high-voltage and high-capacity runs over very long distances, they are better suited to handle the electricity produced by solar and wind farms, which starts out as direct current.

Follow the emerging needs for transformation to renewables and the implementation of more sustainable management policies.

http://www.nytimes.com/2011/11/18/business/energy-environment/direct-current-technology-gets-another-look.html?_r=1&