Telephony and electricity have been always intertwined. AC (alternating current) won over DC (direct current), but DC lived on in the wireline network, where it powered the telephone independently of the electrical grid. Now, with increasing interest in data centers and in their energy efficiency, DC is coming back, according to the NYT.
But those constant conversions cause power losses. For example, in conventional data centers, with hundreds of computers, electricity might be converted and “stepped down” in voltage five times before being used. All that heat must be removed by air-conditioners, which consumes more power.
In a data center redesigned to use more direct current, monthly utility bills can be cut by 10 to 20 percent, according to Trent Waterhouse, vice president of marketing for power electronics at General Electric.
“You can cut the number of power conversions in half,” Mr. Waterhouse said.
On a far smaller scale, SAP spent $128,000 retrofitting a data center at its offices in Palo Alto, Calif. The project cut its energy bills by $24,000 a year.