INTRODUCTION - Wind Resource Assessment: A Practical Guide to Developing a Wind Project - page 1

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INTRODUCTION
For any power plant to generate electricity, it needs fuel. For a wind power plant, that
fuel is the wind.
Wind resource assessment is the process of estimating how much fuel will be
available for a wind power plant over the course of its useful life. This process is the
single most important step for determining how much energy the plant will produce,
and ultimately how much money it will earn for its owners. For a wind project to be
successful, accurate wind resource assessment is therefore essential.
Technologies for measuring wind speeds have been available for centuries. The
cup anemometer — the most commonly used type for wind resource assessment — was
developed in the mid nineteenth century, and its basic design (three or four cups
attached to a vertical, rotating axis) has scarcely changed since.
Yet, an accurate estimate of the energy production of a large wind project depends
on much more than being able to measure the wind speed at a particular time and
place. The requirement is to characterize atmospheric conditions at the wind project
site over a wide range of spatial and temporal scales — from meters to kilometers and
from seconds to years. This entails a blend of techniques from the mundane to the
sophisticated, honed through years of experience into a rigorous process.