Terracotta Cool

Humble clay fends off heat without electricity

- Jyoti Thakur

A LITTLE OVER 20 PERCENT of India’s households own an air conditioner or cooler, and fewer than a third have refrigerators—leaving hundreds of millions of people to face rising temperatures without artificial cooling. Extreme heat is estimated to have claimed more than 700 lives in India in 2024, its hottest year on record, and researchers warn that 76 percent of the population faces high to very high heat risk.

But an innovation that’s at least 3,000 years old—terracotta—is emerging as a low-cost, low-energy alternative. Once used by the Bronze Age Harappan civilization to store water, this clay-based ceramic still stands on the shelves of rural Indian homes as earthen pots that cool water without electricity and cost as little as a dollar each.