Addendum to WindPACT Turbine Design Scaling Studies Technical Area 3 -- Self-Erecting Tower and Nacelle Feasibility: March 2000-March 2001

Global Energy Concepts (GEC) conducted the turbine design scaling study on self-erecting towers for the U.S. Department of Energy's Wind Partnerships for Advanced Component Technologies (WindPACT). This study included an extensive survey and analysis of self-erecting tower techniques, including an analysis of the potential reductions in the cost of energy (COE) resulting from taller towers. TheCOE calculation methodology used in the study incorporated a simplified approach to the annual energy yield calculation by assuming that a given percentage increase in wind speed would result in twice as large a percentage increase in annual energy. Recently completed work identified this as an oversimplification for modern equipment and higher wind speeds. This report presents a revisedanalysis using a more accurate modeling of the relationship between wind speed and energy production in order to more accurately define the potential cost of energy reductions available from taller towers.