Industries & Applications
Cost benefit of ultrasonic anemometers vs mechanical wind sensors in solar farms
How ultrasonic wind sensors offer significantly lower total cost of ownership compared to cup and vane anemometers
Background
According to the International Renewable Energy Agency (IRENA), renewable energy reached a record high last year, with renewables accounting for more than 92% of global power expansion. Solar power led the way, contributing 42% of this growth, surpassing hydropower (29%) and wind (25%). The solar sector alone grew by 32.2%, while the global weighted average cost of electricity from new solar PV projects dropped by 12%, marking the steepest decline in costs among major renewable sources.
Challenge
According to data featured in research by the SwissRe Institute wildfires, windstorms, and tornadoes accounted for 80% of insurance claims at solar farms over the past decade. These extreme weather events underscore the need for accurate and reliable weather monitoring to ensure solar farms operate optimally and the infrastructure remains protected.
Traditional mechanical wind sensors, such as cup and vane anemometers, rely on moving parts, making them susceptible to wear and failure, and subsequently requiring regular maintenance and repair. These sensors become more inefficient with time, as the rotating parts wear, ultimately providing inaccurate wind measurement readings potentially resulting in damage to panels.
The accuracy of cup and vane anemometers is also affected during extreme weather conditions, and their slower response times (due to mechanical inertia) can delay detection of low winds, sudden gusts or turbulence, critical for decision-making in high-risk environments.
Many solar farm operators report needing to replace mechanical wind sensors annually to maintain accurate and reliable wind measurement data required for safe and effective operations. To compound the issue, these mechanical anemometers are often mounted on tall structures and are not easily accessible, requiring an engineer to use a mobile elevating work platform (MEWP), such as a scissor lift, typically costing around $500 to $800 per day*.
Based on industry estimates, a 50 MW solar farm operating even 5–10% below optimal levels, due to sensor inaccuracy, tracking errors or other inefficiencies, can result in $200,000–$500,000+ in annual losses**.
Solution
Accurate, real-time weather data – especially wind measurement – enables solar farm operators to make informed decisions that ensure optimal performance and proactively help mitigate weather-related damage. For example, adjusting panel orientation or initiating a system shutdown in the event of high winds can protect infrastructure and reduce downtime.
Gill’s ultrasonic wind sensors provide continuous, high accuracy wind data with no moving parts, resulting in minimal maintenance and exceptional long-term durability.
While the upfront cost of ultrasonic anemometers may be higher than traditional cup-and-vane sensors, the Total Cost of Ownership (TCO) is substantially lower. Mechanical sensors often demand frequent maintenance visits and early replacements – costs that quickly outweigh any initial savings.
All Gill’s ultrasonic 2-axis anemometers feature a high-quality, low maintenance build and provide long-term measurement accuracy.
Key advantages of Gill ultrasonic anemometers:
- Low total cost of ownership – fewer replacements, lower maintenance effort and reduced overall costs
- No moving parts – minimal wear and virtually maintenance-free
- Fast response time – real-time detection of wind shifts and gusts
- High accuracy and reliability – perform even in harsh conditions, e.g. WindUltra models rated for wind speeds up to 75 m/s (270km/h) and IP66, IP68 & IP69k.
- Long operational life – extremely durable construction
- Full 360° wind direction coverage – critical for dynamic weather environments
- WMO compliance – integrated gust wind speed and direction calculated from a rolling average
By delivering accurate, real-time wind data and eliminating the failure risk associated mechanical anemometers, Gill ultrasonic wind sensors help solar farms maximise uptime, ensuring panels are optimally positioned, while reducing the risk of costly damage and downtime due to extreme weather.
Sources:
* These sources collectively support the $500–$800 per visit estimate when considering equipment rental and operator labour.
- Access Platforms – 10m Electric Scissor Lift Hire
- Tool Hire Centre – Scissor & Boom Lift Hire
- Checkatrade – Cherry Picker Hire Cost Guide (includes operator costs)
** Estimates calculated on figures found in the following sources:
- https://pv-magazine-usa.com/2025/03/05/u-s-solar-facilities-lost-5720-per-mw-to-equipment-underperformance-in-2024
- https://pv-magazine-usa.com/2023/05/03/solar-assets-are-underperforming-expectations-by-8-what-is-the-root-cause
- https://www.pv-tech.org/raptor-maps-us-solar-loses-us10-billion-asset-underperformance-2024
- https://pv-magazine-usa.com/2024/03/13/solar-asset-underperformance-estimated-to-cause-4-6-billion-in-preventable-losses
Recommended wind sensors for solar farm management...
Gill WindSonic is a low-cost 2-axis ultrasonic anemometer, providing wind speed (0-60m/s) and direction data in a robust housing. This anemometer has no moving parts, offering maintenance-free operation in a wide range of applications.
WindUltra is Gill’s smallest and lightest anemometer. It has an extremely robust design, has been aggressively tested to IP69k, provides high accuracy measurement, and is easy to install and use.