War on Current

Just when you thought the war on current between George Westinghouse’s Alternating Current and Thomas Edison’s Direct Current was over, an article is published at businessweek.com advocating for DC.

In the late 1880s the war over AC versus DC was at its peak.  DC power was seen as safer than high voltage AC and was simple.  Edison advocated for a 100volt DC system, with about 110 volts running through the power lines to allow for a slight drop in voltage.  One of the greatest drawbacks of using DC power was the quick voltage drop that resulted from the resistance in transfer.  Every few thousand feet during transfer generating plants were necessary to keep up the voltage.  On the other hand, AC current was able to be transmitted at a high voltage over power lines due to the ease of lowering voltage through a transformer.  Eventually Westinghouse and AC power won the war, so we thought.

Jeff Green writes in businesweek.com, about Paul Savage, CEO of Nextek, manufacturers of lightning protection and  high current DC filters.  The article sites that in the late 1800s and early 1900s many devices ran on AC power, but today there is a constantly growing number of devices that rely on stable DC power, such as the computer and LED lighting.  With homes in the US wired for AC power, each of these devices must contain its own AC to DC adapter.  Paul Savage sees this as a power loss because each conversion from AC to DC wastes a little bit of electricity.  Instead of every device converting AC to DC, Savage says:

“if the electricity coming into a building were converted to DC at a single point, it could reduce waste by as much as 40%.” (Green, 2010)

Savage and Nextek have joined with Armstrong Ceiling Systems (manufacturer of drop ceilings) and Johnson Controls to develop a system of distribution of DC throughout the home.  In a pilot program a few homes in the Detroit area will be retrofitted with DC electrified ceilings.  Savage says:

“They’re safe to touch, so lights, ceiling fans, speakers, and other power hungry items ca be simply clipped in place.”   (Green, 2010)

I can’t help but think about bumper cars that you see in theme parks, but I don’t think its too safe to touch the ceilings there.  The power delivered to the ceiling is converted in something that resembles a “super-sized power strip.”  (Green, 2010)

If DC power could be delivered to homes and all/most AC to DC converters avoided Savage states that the amount of energy used in the United States alone could be reduced by 8.3 percent.  I don’t have the full understanding of how, or how much energy is lost in conversion, but I expected it was a lot.  I think this is a great idea, especially for all of those devices that we use everyday that run on less than 110 volts.  Low voltage DC sounds like a great idea for household use and for reducing energy waste.

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