Tuesday, January 25, 2011

Joint WISA/IEEE Meeting 

Program: Advanced Inverter Design

Matthew Perkins, Sales Manager, GE Power & Water, Solar Technologies 

Talk arranged by Steve Steffel and Peter Caroselli, Pepco Holdings.
Facilities organized by Mary Marchegiano, Head of Del Tech EE Dept

Interesting facts from the presentation:

  • To date, the most activity for solar power has been in Germany and Spain due to a “feed in” tariff favoring use of solar energy. However, this will soon end. The biggest potential market is expected to be in the US, but this has not taken off. 
  • Total power delivery by GE and others in the European “feed in” markets were 5GW in 2008, rising to an expected 
    12 GW in 2013.
  • Key markets in the US are  New Jersey, California and Texas.
  • GE is now concentrating on the CdTe thin film technology. GE's position in crystalline-silicon was not competitive. 
  • The GE 1 MW large inverters planned for use in large solar installations were originally developed for GE's wind technology. The technology boosts to 677V in the first stage then down converts to 480V. It is a liquid cooled design, to give full output at 50 degC. For solar power, the first stage deals with array management. The second stage deals with grid connection. 
  • Some challenges with the design are that the wind application has a much smoother power output; solar power can change precipitously. This stresses the power management for inverters, especially on cloudy days.
  • Adding backup storage where solar is the primary source tends to destroy the economic advantages. 
  • GE inverters use the Pulse Width Modulation technique.
  • GE Energy manufactures the large inverters discussed here. The appliance division manufactures the smaller 1-5 Kw units. 
  • As more renewables come on line, the spot price will expect to drop. The overall cost is not expected to be affected.
  • GE has a partnership with GM to investigate hooking Chevy Volts to the grid.

More Information: 
Perkins IEEE Advanced Inverter Design   805 KB
WWSIS_Executive Summary_PRINT   6889 KB