Need to establish weather stations at wind, solar plants of 50 MW: CEA

In an effort to enhance grid reliability and efficiency of green energy projects, the Central Electricity Authority has proposed that an automatic weather station needs to be installed at wind and solar plants of 50 MW or above by the developer.

In February, the Central Electricity Authority (CEA) issued an advisory on co-locating energy storage systems with solar power projects to enhance the cost efficiency and stability of the grid.

The solar and wind generation depend on weather conditions. There are issues like not getting accurate weather forecasts. Many a time, forecasting errors result in significant financial penalties under the Deviation Settlement Mechanism (DSM), the Central Electricity Authority (CEA) has said in a notification dated July 7.

There is a need to install automatic weather stations in solar and wind power plants, the CEA said, adding that it has prepared guidelines for the same and directed all renewable energy implementing agencies (REIAs) to include the requirement of automatic weather stations in bid documents.

"Accurate measurement of critical meteorological parameters would optimise RE generation. Also, it would improve overall generation predictability, efficiency, enhance grid reliability and ensure regulatory compliance," the notification said.

As per the guidelines, the automatic weather station (AWS) should be installed at a location within the renewable energy project site.

"Typically, one AWS per RE plant is to be installed for 50 MW and above RE (or as per respective SERC regulation) capacity connected at the intra-state network, and ISTS-connected RE plants shall be governed by respective regulations of CERC," the CEA guideline said.

For solar power plants, the AWS should be located in terrain that closely resembles the overall site conditions, with irradiance sensors mounted at the same tilt and orientation as the photovoltaic modules.

For the wind power projects, the AWS must be positioned in areas that reflect the true wind regime of the site, turbulence zones, or artificial barriers.

The area of the AWS site should be 10m x 10m. The site should be levelled and made free of obstructions like buildings, structures, trees, bushes or equipment that could cause shading, turbulence, or other local interference. Herbicides should be sprayed, and sites should be cleaned.

The AWS should be capable of measuring several parameters like wind speed and rainfall (mm), and converting them to a digital format for transmission to the Data Acquisition System (DAS).