My name Philippe Drobinski and I'm going to be your guide on this blog.

I'm a former engineer, professor at the Ecole Polytechnique, and

researcher at CNRS in atmospheric physics.

Wind energy is referred as a variable generation source

because its electricity production varies based on the availability of wind.

Some aspects of wind variability are predictable.

Other aspects, such as intermittent wind gusts, are much less so.

To calculate the likely power output from a given wind turbine, it is necessary

to characterize the wind energy available in a planned wind turbine farm location.

And this is on what we will focus on this block,

on the characterization of the available wind energy in a specific site.

We will guide you to be able to classify a data set from a long series of

measurements for further statistical analysis.

Build a wind speed probability density function, also called PDF,

from the data set.

And model this data using a Weibull or Rayleigh distribution.

Let's start by working at a 12 hour wind speed measurement series from.

Some aspects of wind variability are predictable.

Other aspects, such as intermittent wind gusts, are much less so.

Focusing on the variability, the wind speed can change over seconds,

minutes or hours.

Most changes are generally small and caused by random events,

also called turbulence.

Over several hours however, these changes can be of much more importance and

tend to be more predictable as related to meteorological changes or local events,

as the wind breeze for example.

The variability of wind speed is important to characterize the wind power, so

statistical analysis will be necessary.

As the average wind speed in a location only paints half of the picture,

the full distribution of wind speed values might be necessary.

This means we will use probability theory.

In probability theory, a probability density function is a function that

describes the relative likelihood for a random variable to take on a given value.

In our case, the random variable is the wind speed.

In our illustration, we have taken a one week measurement of wind speed.

The wind energy assessment would need longer series

of at least one year measurements in the location of interest.