It’s no surprise that renewable energy projects reliant on site conditions benefit greatly from accurately understanding the ambient environment. With this Meet & Greet series, we’ve talked about anemometers that sense wind speed and wind vanes that detect wind direction. The next piece of the puzzle is understanding air mass or air density. To do this, we use air pressure sensors, also known as barometers!
Different models for different settings
Here at Energy Canvas, we carry four main models of barometers: AB 60, AB 100, Vaisala PTB100, and Thies. From a user’s perspective, the main difference between the models is the measuring range. The upper bounds are quite consistent with all four models being able to measure air pressure at up to 1100 hPa. Where they differ is in their lower bounds, ranging from 300 to 800 hPa.
The AB 60, which is a piezoelectric barometer, represents one of the more mainstream models. It is able to measure air pressure from 800 to 1100 hPa, making it a popular choice for many renewable projects and applications in meteorology. Instances that require a larger measuring range might call for its higher specification counterpart, the AB 100, which measures from 600 to 1100 hPa. For reliable performance in much lower air pressure environments, the Vaisala and Thies models are both solid choices that can detect air pressure down to 500 hPa and 300 hPa, respectively.
What are piezoelectric barometers? (The 30-second version)
Piezoelectricity is the generation of electricity by applying physical compression to piezoelectric materials, which are specific substances that are usually very hard in nature, such as quartz or ceramic. Using this concept for barometers, a structure called the “diaphragm” senses the physical force of air particles. This physical compression is then transferred to the piezoelectric material, generating a voltage, which is amplified to create an output signal interpreted by a data logger (such as the Meteo-40 Plus) to come to an air pressure reading.
WIIFM (What’s in it for me)?
For development stage wind projects, quality air pressure and temperature measurements can significantly affect prediction accuracy of annual energy production (AEP). By installing quality barometers closer to hub height, the measurement campaign can better estimate air pressure experienced by the wind turbine, leading to improved production confidence, which we all know means better project financing rates and returns. Quality air pressure measurements can be incredibly valuable for operational wind projects too because depending on the topography, air pressure can fluctuate considerably and rapidly. In cases like this, installing a high-performing barometer will help to inform the project SCADA so that it can be operated more effectively, and thus improve operating availability.
For solar projects, air pressure measurements help to increase accuracy in determining climatic conditions experienced by the project. Like on wind projects, during the development phase of a solar project, barometers are used to determine air mass which is fundamental in estimating productivity. For operational solar projects, pressure changes can inform operators of impending conditions, which influence production forecasting and potentially cleaning cycles too.
Curious to know which barometer best suits your project goals? Get in touch with us! But of course, no “pressure.”