A wind turbine is a tall machine that uses the wind to turn a generator and make electricity. Wind turns three long blades. The blades turn a shaft, the shaft turns a generator, and the generator produces alternating current. Wind farms in Tamil Nadu, Gujarat and Karnataka have thousands of them.
The main parts sit at the top of a tower, in a housing called the nacelle. A new onshore turbine in India stands on a tower 120 to 160 metres tall. Its blades are about 70 metres long, and it makes 3 to 5 megawatts (MW) at its best. Older turbines are smaller. It makes less than that in light wind, so a farm gives only a part of its rated power over a year. Below a certain wind speed the blades do not turn at all, and above another speed the turbine is shut down to protect it.
A modern turbine is also a computer. It has sensors for wind speed, blade angle, the temperature of its gearbox and the vibration of its bearings. The software turns the whole machine to face the wind and tilts the blades when the wind is too strong. It sends all its readings to a control centre, which may be in another country.
Here is a typical case. A turbine in a wind farm near Kanyakumari has a gearbox whose vibration rises slowly over three weeks. The maker's software in its control centre notices the pattern. It does not wait for the gearbox to break. The maker books a repair visit for a calm week. A gearbox that fails outright needs a crane and can keep the turbine idle for days, so the planned visit costs less. This is predictive maintenance. It is part of a service contract that can last 20 years or more, the business known as aftermarket service.
The readings go to remote monitoring by the maker and to asset performance management software, which the wind farm owner uses to compare turbines. A drone or a crawling robot can look for cracks on the blades, which is robotic inspection. The electricity itself goes to the grid operator's energy management system, which can order a turbine to reduce its output. A turbine can also supply an electrolyser that makes hydrogen.