The Central Electricity Authority (CEA) has proposed the installation of one automatic weather station (AWS) for each renewable energy project with a capacity of 50 MW.

The proposal is in the context of the need for real-time weather measurement to optimize renewable energy generation, as solar and wind generation depends on weather conditions.

Weather forecasting errors have also resulted in renewable energy project developers incurring significant financial penalties under the deviation settlement mechanism.

The CEA requested renewable energy implementing agencies to include in their tender documents the condition that renewable energy projects must install AWS.

According to CEA’s guidelines, the AWS must be within the renewable energy project site and have a minimum size of 10 m x 10 m.

The AWS for solar projects must be on a terrain similar to the project site. The irradiance sensors must be mounted at the same tilt and orientation as the solar modules. The AWS for such projects must be able to measure global horizontal irradiance, global inclined irradiance, and rainfall.

For wind projects, the AWS must be in areas that closely resemble the true wind conditions of the site, including turbulence zones or artificial barriers near the project site. The AWS for such projects must be able to measure and collect data on barometric pressure, ambient air temperature, wind speed, wind direction, and relative humidity.

According to the guidelines, the weather data must be collected from the AWS site and disseminated at an interval of 15 minutes. This duration can be reduced to one minute during extreme weather conditions.

The AWS must also be accompanied by a data acquisition system (DAS) with provision for a 24-hour, real-time, battery-powered clock to ensure times are recorded even during a power outage.

The DAS will exchange data with the National Centre for Medium-Range Weather Forecasting.

The data collected must be maintained for a minimum of 180 days.

A solar-powered battery must also support the AWS to allow access even in remote areas. The battery must be able to run the system for at least 20 days on full load during total cloudy and foggy conditions without needing solar power.

The AWS mast must be made of anodized aluminum alloy and stand at least 10 m high. It must also be supported by three steel guy wires and a concrete platform at the base.

The weather station must be accompanied by two earth pits for signal earth and a lightning arrestor.

Renewable energy generation is highly dependent on weather conditions. Solar power generation experienced sudden dips between December 2024 and February 2025 due to cloud cover over large swathes of northern India, resulting in demand-supply gaps that led to low frequency and localized high voltages in the grid.

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