Tracking the sun with automation for efficiency in solar power production

Smart sensors, automated weather stations, machine learning algorithms comprise a market worth $10 bn

Renewable energy may be available in abundance, but capturing and harnessing gigawatts of power is no easy task. Increasingly, sophisticated technologies are being deployed to maximise the absorption and management of solar energy.

For solar energy plants, the key to success are trackers that ensure maximum capture of sunlight. Trackers have become a multi-billion dollar industry as the number of solar farms increase across the world. The use of smart sensors, automated weather stations, and machine learning algorithms promises to increase the efficiency and supply of solar energy.

Various estimates place this market to be worth $10 billion and growing steadily. Solar trackers enable panels to follow the movement of the sun and enhance energy output by 20 per cent to 40 per cent compared to fixed systems. NASDAQ-listed solar tech firm Nextracker is deploying smart trackers for solar projects by Indian companies.

NTPC is using smart solar trackers in its Nokh Solar Project. It will be one of India’s largest solar parks. Amara Raja is executing this 306-megawatt peak (MWp) project in Rajasthan. NTPC is also using smart trackers with Sterling and Wilson for its 1.25 GW Solar PV Project in Khavda RE Park, Gujarat.

Nextracker says that it has created machine-learning-based software that combines advanced sensors, weather forecasting, and machine-learning technologies to maximise energy generation for new and existing solar ----- plants. The software has an intelligent, self-adjusting tracker control and yield optimisation system that continuously optimises the tracking algorithm of each individual row, boosting solar energy production.

The trackers work on sensors that monitor the movement of the sun. As the sunlight changes through the day, the trackers slowly shift the angle of the panels to synchronise with the sun.

The most important aspect is the creation of bifacial panels. These panels can absorb sunlight on both sides based on the direction of the sun. The software of the tracker system incorporates site topography, as-built conditions, site-specific weather data, and real-time feedback from its smart controller to make informed decisions and MINIMISE shading between panels.

Solar tracking begins at the stage of designing the solar farm. While the angle of the sun and its movement is predictable to an extent, the actual sunlight on a spot is influenced by micro-weather conditions and the land topography. The key objective is to enhance energy capture.

“We create digital twins and digital topography so that we've can count for every day of the year,” says Alex Au, global chief technology officer of Nextracker. “We spend a tremendous amount of time doing wind tunnel studies.” Planning for each location and topography is done with a digital-twin process much before a solar plant is commissioned. The process has allowed Nextracker to plan for 90-mile-an-hour wind events and undulating land. Solar power plants are often situated in remote locations, posing challenges for maintenance.

The digital twin software provides a convenient solution for solar plant operators. They can install or upgrade controller software without physically visiting the site. The digital twin establishes a two-way communication channel between tracker devices and a remote operations center.

In the past, most solar farms were built on flat land because of predictable and consistent sunlight. But the use of smart trackers has allowed companies to establish panels on sloping or undulating land. Undulating land receives sunlight from different directions during the day. With the use of smart trackers, the panels can move according to the specific patch to maximise energy capture. Now land gradient is no longer an obstacle for solar farms.