Concentrated solar power, in which reflective troughs heat up water that is then fed to heat exchangers and turbines to produce electricity, could play a key role in India’s energy future.
In central Karnataka state, 120 miles north of Bangalore, the lush jungle of India’s west coast gives way to dry scrubland. Sunflowers, onions, chilis, and groundnuts grow in parched fields. In scattered, populous villages, concrete buildings alternate with ramshackle thatched huts. Cows nose through the garbage, and wooden carts drawn by horned oxen crowd the streets. Rough brick-producing factories belch black smoke into the air. Much of the scene appears as it did a century ago. But in a walled compound just beyond the town of Challakere sits an installation that could hold one of the keys to India’s energy future.
The project, run by the Bangalore-based Indian Institute of Science (known as IISC), is a test array for concentrated solar power. Rows of shallow parabolic troughs, made of specially coated aluminum, stretch for more than the length of two and a half football fields. Above them are water pipes set to catch sunlight reflected from the troughs. When the project begins operation in a few weeks, the water in the pipes will be heated to 200 °C (392 °F); the hot water will go to a heat exchanger attached to a small turbine that will produce 100 kilowatts of electricity.
A part of the Solar Energy Research Institute for India and the United States (SERIIUS), this small solar array will be used to test various reflective materials and heat-transfer fluids (including, for instance, molten salt in addition to water) from multiple manufacturers. Dozens of small wireless sensors will collect data and send it via the Internet to a dashboard at IISC, where it can be analyzed and catalogued. The objective, says Praveen Ramamurthy, a professor of materials engineering at IISC, is to find the combinations of components that best suit conditions in India, which under the National Solar Mission of Prime Minister Narendra Modi is poised to become one of the world’s largest solar markets in the next seven years.
The Indian subcontinent, as has often been noted, is a world unto itself, encompassing the rainforests of Assam, the deserts of Rajasthan, and the Himalayan plateaus of Ladakh. Finding solar panels that will stand up to these extreme conditions will be critical to Modi’s goal of building 100 gigawatts of solar capacity by 2022. “Nobody is testing for the aging