Voyager: Since soot has detrimental effects on humans and their surroundings, why aren't solar stoves used worldwide?

Roughly three billion of the world’s poor are forced to use biofuel for cooking. Many make their own mud stoves and just feed in wood or sticks or dung as fuel.

It’s convenient because the fuel is free. They just go around and collect what’s available.

They cook this way not because they want to destroy the environment but simply because they have no access to fossil fuels such as coal or natural gas. Even if they had access, they can’t pay for it.

The goal of our Project Surya is to observe the atmospheric and climate effects of replacing these kinds of stoves, which produce soot and other forms of black carbon in the smoke they generate. We will experiment with the effects of solar stoves as well as other kinds of alternative cookers that emit either no smoke or much less smoke. We will also be observing which ones are most popular among the users.

But there are practical reasons that solar cookers might not be used everywhere. They must be set up outside to capture sunlight, which might make them impractical for everyday use, especially in urban settings where there is limited outdoor space.

In addition, many potential solar stove users in rural settings will have difficulty affording these cookers. We believe that the use of these cookers in conjunction with other clean-burning stoves can make a difference toward decreasing the rate of global warming and reducing air pollution, even if only used by a portion of the world’s population, but understand that widespread use will require help from governments from local to national levels.

— V. Ramanathan, distinguished professor of climate and atmospheric science, Climate, Atmospheric Science, and Physical Oceanography division