Session: Research Posters

Paper Number: 112828

112828 - Experiential Learning of Met Tower Instrumentation for Wind Energy Assessment 

Met towers are installed to measure wind resource during the initial prospecting phase of wind energy development. Wind resource assessment entails estimation of the free stream wind speed at the hub height of a wind turbine. Wind energy assessment also includes converting the wind resource into energy numbers considering various dynamics among wind turbines and constraints of the project including offtake of the generated wind power. A significant amount of uncertainty is involved in wind energy assessment. We install anemometers at multiple heights to reduce uncertainty associated with the wind speed extrapolation. A typical height of a met tower used in the wind energy industry is about 50 to 60 meters whereas hub heights of wind turbine are nowadays in the range of 80 to 90 meters.

In this paper we summarize an outdoor laboratory setup at Appalachian State and the experiential learning with students of sustainable technology utilizing important concepts from fluid dynamics (stagnation, wakes, tower shadow etc.) to inform configuration and instrumentation of a met tower. The tower is instrumented at three levels to facilitate extrapolation of wind speed to the hub height of the wind turbine. At each level there are two anemometers, known as primary and redundant anemometers, to help isolate tower shadow from measured data and also to enhance data availability. There are two wind vanes at two levels, and temperature, pressure and relative humidity sensors to estimate density of the air. We precede this field lab with introduction to the master equation of the wind power to introduce measurement variables. In this experiential learning, attention is given more to the orientation and positioning of the sensors with reference to the predominant wind direction and dimensions of booms to minimize tower shadow effect following recommendations of IEC 61400-12 Standards.

This lab is a part of the Wind Power Technology (TEC 4607) course at Appalachian State. This outdoor lab is designed for two sessions, each two hour long. In the first session students learn to assemble tower components and raise and lower the tower with the help of a gin-pole and winch under supervision of the instructor.  In the follow up session, the students instrument the towers on the ground, wire sensors assigned to them into the logger, perform functional test of the sensors, and raise the tower. Students learn the importance of working in a team to commission or decommission a met tower. This laboratory is designed to give students hands-on experience important to the wind energy industry and problem solving in general. The student will learn how to commission and perform O&M on met tower to ensure a bankable stream of wind resource data.     

Presenting Author: Ram Poudel Appalachian State University

Presenting Author Biography: Ram Poudel is assistant professor at Appalachian State University.

Authors:

Ram Poudel Appalachian State University
Brian Raichle Appalachian State University