Weather balloons used to probe wind farm effects

Friday 09th Sep 2011 by theWeather Club

The National Oceanic and Atmospheric Administration's (NOAA) Air Resources Laboratory (ARL) is planning to launch a series of research balloons above a wind farm in Texas to study the nature of the atmosphere above wind farms. The balloons will contain a small, lightweight instrument package designed to transmit real time measurements on wind speed, wind direction, temperature and humidity back to a ground station for analysis. Over a nine day period starting on September 12th the balloons will be launched at varying times throughout each day, rise for between 30 to 35,000ft and then float back to earth under bright orange parachutes.

What will be observed is how the atmospheric flow above the wind farm changes in both space and time. "We want to get a better picture of what the vertical atmosphere looks like near a wind farm," said Will Pendergrass, a physical scientist at NOAA's ARL Atmospheric Turbulence and Diffusion Division. "The information we collect will be used by the weather forecast models to help wind farms estimate how much power they can produce and when they can schedule maintenance."

Forecasting the winds at different heights in the atmosphere in the vicinity of wind turbines is a critical component to estimating wind power, since relatively small changes in wind speeds can lead to large changes in the amount of power a facility can produce, and thus the demands that can be placed upon it. Predicting total power outputs over 24 hour periods is an important operational aspect in the modern wind power industry. It is predicted that the better the forecasts of wind power production, the lower cost to power producers, and therefore to the consumer.

ARL has a long history of research focused on low level winds and turbulence in the planetary boundary layer, which is the portion of the atmosphere closest to and most influenced by the Earth's surface. The project is part is of a Cooperative Research Agreement with Duke Energy - who own the wind facility above which the measurements will be taken - and hopes to improve the ability of the renewable energy industry to accurately forecast winds at the height of the turbine blades.