No electricity, no diesel: Sonam Wangchuk's invented tent can stay warm at -14 degrees. How does it work?

What if a tent could stay warm in freezing Himalayan temperatures without relying on conventional heating? In 2021, innovator Sonam Wangchuk showcased a portable tent designed to harness sunlight and retain heat in extreme cold. He said the tent could maintain a temperature of 15 degrees Celsius at 10 pm when the outside temperature had fallen to -14 degrees Celsius. The Made-in-Ladakh innovation was designed to reduce dependence on kerosene while providing a warmer, more sustainable shelter in high-altitude regions.

How Sonam Wangchuk's tent stays warm at -14 degrees

The secret behind the tent lies in how it captures, stores and prevents the escape of heat. According to information from Ornate Solar, sunlight enters the tent from the south-facing side and heats a specially designed front chamber. The chamber uses a polycarbonate structure that allows sunlight to enter but prevents the captured heat from escaping easily.

The sleeping chamber is positioned towards the north and is surrounded by insulation. The insulation works much like the material used in sleeping bags, helping retain warmth inside the space. The tent also features a wind-cheater covering designed to prevent cold winds from lowering the temperature inside. Its round structure serves another practical purpose. By reducing the exposed surface area, the design helps minimise heat loss.

During the daytime, the tent also includes a dedicated solar lounge with seating, allowing occupants to sit and make use of the warmth generated by the sun.

Tent could remain warm even when it was -14 degrees outside

In a 2021 post on X, Sonam Wangchuk shared details of the innovation, describing it as a solar-heated tent and saying that it had reached 15 degrees Celsius inside at 10 pm while the minimum outside temperature the previous night was -14 degrees Celsius. He said the design could accommodate 10 people and was fully portable. Wangchuk later clarified that the entire tent did not weigh less than 30 kg. Instead, each component weighed less than 30 kg when dismantled, allowing the parts to be carried to mountain locations.


He added that an ultra-light aluminium version had individual components weighing less than 20 kg.
The design was aimed at reducing the use of kerosene and the pollution associated with burning the fuel in fragile Himalayan environments. By using sunlight as its source of heat, the tent also offered a renewable alternative for maintaining warmth in extremely cold conditions.

Why the portable design matters

The ability to dismantle and transport the tent is particularly important in high-altitude locations where conventional infrastructure can be difficult to establish. The design was intended to reduce dependence on fuel while providing warmth in temperatures as low as -14 degrees Celsius. Avoiding the burning of large quantities of kerosene could also help reduce carbon emissions and pollution in the Himalayan region.

The concept combines passive solar heating, insulation and a compact structure rather than relying solely on an external heating system.

Who is Sonam Wangchuk?

Sonam Wangchuk is an Indian education reformist and innovator who has spent more than three decades working on education and sustainable solutions in Ladakh. As per the Ramon Magsaysay Award Foundation, Wangchuk opened SECMOL School in 1998. The institution focused on rebuilding the confidence of Ladakhi students, developing their life skills and offering courses ranging from leadership training to solar power installation.

Wangchuk had founded SECMOL in 1988 with the aim of bringing reforms to the government school system in the trans-Himalayan region of Ladakh.

His work has also extended to climate adaptation. As climate change affected natural water supplies for agriculture, Wangchuk developed the idea of artificial glaciers known as ice stupas. These conical structures store water during winter and release it gradually as they melt during summer, helping provide irrigation water for farms.

The Ramon Magsaysay Award Foundation describes Wangchuk as a natural innovator who works from local experience and develops optimistic solutions. He has summed up his approach with the belief that “the possibilities are endless.” A mechanical engineer by education, Wangchuk has received several honours for his work, including the Ramon Magsaysay Award, the Global Award for Sustainable Architecture by UNESCO and the Governor's Medal for educational reform by the Government of India.