In the southern Indian city of Tuticorin, locals are unlikely to suffer from a poorly risen cake. That’s because a coal-fired thermal power station in the area captures carbon dioxide and turns it into baking soda.

Carbon capture schemes are nothing new. Typically, they use a solvent, such as amine, to catch carbon dioxide and prevent it from escaping into the atmosphere. From there, the CO2 can either be stored away or used.

But the Guardian reports that a system installed in the Tuticorin plant uses a new proprietary solvent developed by the company Carbon Clean Solutions. The solvent is reportedly just slightly more efficient than those used conventionally, requiring a little less energy and smaller apparatus to run. The collected CO2 is used to create baking soda, and it claims that as much as 66,000 tons of the gas could be captured at the plant each year.

Its operators say that the marginal gain in efficiency is just enough to make it feasible to run the plant without a subsidy. In fact, it’s claimed to be the first example of an unsubsidized industrial plant capturing CO2 for use.

It’s a glimmer of hope for the clean coal industry. A string of U.S. problems, among them the wildly expensive Kemper power plant and the folding of Peabody Energy, which bet heavily on clean coal, have served to demonstrate that baking carbon sequestration in from the get-go is economically challenging. But successes of retrofitted systems, such as the W.A. Parish Generating Station in Texas and the Tuticorin scheme, demonstrate that adding capture systems can prove feasible.

Bloomberg New Energy Finance predicts that solar power may, on average, be cheaper than coal by 2025—so coal's future as a means of generating power could be limited. But we may still be able to clean up existing plants—and bake some nice cakes along the way.

(Read more: The Guardian, Bloomberg, “A Huge Carbon Capture Scheme Provides New Hope for Clean Coal,” “A Mississippi Power Plant Highlights All That’s Wrong with Clean Coal,” “Peabody Energy’s Bankruptcy Shows the Limits of Clean Coal”)