Sonam Wangchuk’s solar tent keeps soldiers warm at -14°C without fuel

Leh: Innovator Sonam Wangchuk has built a solar-heated tent that stayed at +15°C inside when it was -14°C outside, without using any fuel, electricity or flame.

The design is aimed at Indian Army soldiers posted at high altitude, where about 50,000 troops spend winters in freezing conditions. Till now, heating relied on kerosene and oil hauled for days — costly, polluting and risky in sealed shelters.

The tent works with a south-facing wall that traps sunlight by day. Water stores the heat and the insulated walls hold it through the night. “It uses the sun to collect the heat, water to store it, and the tent’s insulation to retain it for jawans at night,” Wangchuk said.

Made of 40 pieces under 30 kg each, the tent can be carried to posts where vehicles cannot go. A 10-soldier unit costs around Rs 5 lakh, about half the price of container cabins.

This is Wangchuk’s second prototype. The first was made a decade ago for Ladakh nomads. The new version was built at the Himalayan Institute of Alternatives with Army inputs and will be tested at Chang-La pass at 17,600 feet.

With Ladakh getting nearly 300 days of sunshine a year, the team says the tent could provide a fuel-free heating option for winter deployment.