The Central Electricity Authority (CEA) has released comprehensive guidelines for Automatic Weather Stations (AWS) for solar and wind power plants, dated July 2025. The primary goal of these guidelines is to ensure accurate and real-time meteorological data collection to improve the predictability, efficiency, and grid reliability of renewable energy generation while ensuring regulatory compliance.
According to the guidelines, each renewable energy project of 50 MW and above should install at least one AWS. For solar power plants, the AWS must be located in a terrain that reflects the site’s conditions, with sensors aligned to the photovoltaic module tilt and orientation. For wind projects, the AWS must be sited to capture true wind conditions, avoiding turbulence zones or obstructions. The AWS site must be 10 m x 10 m, clear of any obstructions, fenced securely, and levelled.
The mast used must be 10 meters high, made from anodized aluminium alloy, and supported by stainless steel guy wires. A concrete platform must support the mast. Rain gauge, temperature, humidity, wind sensors, and barometric pressure sensors are to be installed at designated positions. The rain gauge, for instance, must be 3 meters away from the mast.
The AWS must measure parameters such as wind speed, wind direction, air temperature, humidity, barometric pressure, and for solar plants, global horizontal and inclined irradiance, and rainfall. Sensors used include thermopile-based pyranometers, ultrasonic wind sensors, siphon tipping bucket rain gauges, and barometric pressure sensors, each with specific accuracy and environmental protection requirements.
The Data Acquisition System (DAS) is a crucial part of the AWS setup. It must interface with all sensors without requiring external signal conditioning and support encrypted data storage for a minimum of 30 days. DAS must also support time synchronization via satellite, preferably NAVIC, and maintain time logs even during power outages. It should include display features and menu-driven interfaces, and support secure remote access only under emergency and approved conditions.
The communication system must support 3G/4G/5G connectivity with dual SIMs and allow secure transmission of real-time data to central agencies like NCMRWF and IMD. The data must also be shareable with local SCADA systems, ensuring compliance with cybersecurity standards, including IP whitelisting, firewall protection, and 180-day data log retention. The DAS must include real-time quality control checks aligned with WMO standards to ensure data accuracy and consistency.
For power supply, the AWS must be capable of operating remotely with solar-powered Maintenance-Free batteries, capable of sustaining operations for at least 20 days without recharge. The weatherproof enclosures for electronics and batteries must be FRP-based with IP66 protection and suitable for harsh environmental conditions.
In summary, these guidelines aim to standardize the deployment of AWS across renewable energy sites in India, enabling reliable weather data collection, enhanced forecasting, and integration into national weather models for better renewable energy planning and operations.
