Wednesday, November 11, 2009

Program: How DC Power Networks are Poised to Make a Thundering Comeback
(Topic was changed to Re-Inventing the Grid with Your I-Phone)
Paul Savage, CEO Nextek Power Systems 

Reason topic was changed: The internet can provide communications to measure and control a balanced power generation and delivery.

Some points noted during the talk:
  • One of the drivers toward DC power is the need to meet renewable energy goals. 
    For example, New York may miss their goals by 50%. 
  • Smart grid; some guiding principle talking points:
  • Reliability/Storage/Distributed generation
  • Efficiency/Sustainability/Renewable Inputs
  • IT/Communications Leverage
  • Load Awareness/Demand Side Management
  • Growth in load today is mostly due to DC motors, computer bricks, industrial computers and controls. The big user today is the variable speed motor, used in air handling, lighting, computing. Technologies going to DC are variable frequency drives and induction motors. Items probably not going DC in the near future are, for example, large installations such as chillers.
  • NTT (Japan) is looking at moving away from AC for data center due to reliability issues.
  • Deployment of Solar Photovoltaic panels is increasing. In recognition of the need for distribution, Armstrong has developed a ceiling panel with an integral DC wiring grid for low voltage DC. See Flex-Zone products. (see
  • For now, the DC option will be limited to lower voltage, such as ceiling panels at 24 volts and about 100 amps, and IT installations probably at 300 volts. One problem with high DC voltages will be switching. So the distribution will have to be high voltage AC transmission to a node, such as a building, and inversion to DC for distribution to the load.