Wind velocity forecasting to help power evacuation

CHENNAI: Wind power producers in the state can look forward to selling much of the power they generate as TNEB is likely to consider evacuating it based on a forecasting system. Every year, there have been complaints from wind power generators about TNEB’s inability to completely evacuate the power they generate between May 15 and September 15. Though Tamil Nadu has 7800MW installed capacity of wind power, the maximum in any state in the country, only 3000MW or less is evacuated due to lack of adequate infrastructure.

Wind, unlike solar, is highly unpredictable and according to experts, wind generation can drop or increase by a few thousand MW just in a matter of minutes.

Hence, shutting down thermal plants to free transmission lines to evacuate wind energy may result in power disruption. It is only to avoid such vagaries that wind generators have set up a pilot project with an expert from Spain to forecast wind speeds and inform Tangedco at least one day in advance.

"At present, there is no forecasting system to evacuate wind. We keep thermal units running and if wind generation is available, we evacuate it and add to the grid. But thermal units cannot be shut completely to evacuate wind energy as there is no certainty about wind power generation," said a TNEB official.

It is only to dispel such problems that wind power generators have appointed Spanish agency Vortex Factoria de Calculs to study evacuation, said the official.

"Wind power varies on daily, seasonal and annual basis. There are basic patterns and averages but it is difficult to depend on it. Forecasting software aims to forecast the velocity of wind for several hours and even the day ahead. Depending on the forecast, other modes of generation can be put on standby mode. The idea is to minimize the number of surprises," said US-based wind energy expert Drew Robb.

The forecast is done based on wind data obtained from a European Metrological Agency. The data, along with the height of the windmill and the wind pattern, is analysed and then forecast is done.

"At present the company is collecting data from sub-stations on past generation. Then the company officials will visit wind mill areas like Kayathar and analyse the height of the wind mills and the wind pattern. Based on computer simulations, it will forecast for a particular area initially and then extend it to other areas," said an official of National Institute of Wind Energy.

The pilot project was launched by the Union ministry of new and renewable energy at a function organized by the institute.

"Vortex Factoria de Calculs, S.L., Spain is ready to provide its wind power forecasting services initially in Tamil Nadu and will be extending across the country. The wind power forecasting project aims to provide forecast of wind and wind power from wind farm/substation to support the scheduling and dispatching process of electricity for wind power generators," said the official.