For over a decade, the U.S.-based Advanced Studies in Appropriate Technology (ASAT) Lab, Inc. has partnered with the Zhejiang Huiwenmei Stove Company (SSM, formerly the Shengzhou Stove Manufacturer) in China. In 2019, they jointly launched the Jet Flame, a new accessory that improves combustion in wood-burning stoves.

ASAT CEO Dean Still and SSM CEO Jack Shen recently spoke with Peter George, the Clean Cooking Alliance’s Senior Director for Private Sector & Investment, about the Jet-Flame’s potential benefits for users of biomass stoves.

This interview is part of a series of conversations the Alliance is having with business leaders across the clean cooking sector. Shrikant Avi, the Alliance’s Senior Manager for Private Sector & Investment, contributed to this interview.


Peter George (George): Can you describe the history of the partnership between ASAT and SSM?

Dean Still (Still): Starting in 2004, Aprovecho Research Center (ARC), an innovation-focused non-profit that develops biomass cookstoves, was hired by the Shell Foundation to bring the wood-burning “rocket stove” to India. We found that cookstoves were not generally factory-produced in India, so ARC identified SSM, a stove manufacturing company located near Hangzhou, China, in 2007. The company had a long tradition of manufacturing affordable, insulated, abrasion-resistant refractory ceramic combustion chambers, which are a key component of high-performance stoves. Tens of thousands of SSM stoves were exported to India, and ARC has worked closely with SSM ever since. We see tremendous synergies between our research and development expertise and SSM’s core competencies in manufacturing to jointly bring durable, high-performance, and well-made products to market. We created ASAT in 2008 as a for-profit venture focused on marketing high-quality, innovative stoves.

George: What role has each company played in developing and launching the Jet-Flame?

Still: In 2018, ASAT was hired by the Bill Gates-supported Global Good Fund (Global Good) to co-develop a solution to integrate fan-driven jets of air into a rocket stove, to dramatically reduce emissions. ASAT built on previous work to develop the concept of a stove accessory, and the Jet-Flame was born.

Jack Shen (Shen): ASAT brought this idea to SSM, and our engineering team and other staff worked together to create the finished product. SSM has rich experience in developing and manufacturing stoves, which we used to turn the Jet-Flame prototype into a final product. At the same time, our strong supply chain management and quality control capabilities ensure that the Jet-Flame is high-quality, durable, and affordable.

George: Tell me a bit about the Jet-Flame technology and its potential to support universal access to clean cooking.

Still: Previous research showed that fan-driven jets of air, introduced underneath the fire, could make stoves significantly cleaner-burning and more efficient. As an accessory, the Jet-Flame can complement a range of cooking solutions including open fires, mud stoves, and earthen and metal rocket stoves, dramatically improving the performance of existing biomass stoves. In an ARC lab test based on International Standards Organization guidelines, the stick-fed Jet-Flame in a mud-brick rocket stove resulted in Tier 4 for emissions of fine particulate matter (PM 2.5) and carbon monoxide, and thermal efficiency.

George: How does the technology and its price compare to existing biomass stove solutions in the market?

Still: Technology is only helpful to the extent that it is adopted. The Jet-Flame was designed for use in existing stoves and in an open fire, reducing the required investment. With a US $10 wholesale cost, the Jet-Flame is a good start in terms of affordability; with increasing scale and design refinements, we hope that a US $10 retail price can be achieved.

The Jet-Flame was initially designed for grid-connected consumers who still use biomass, and for current owners of a solar home system. A US $20 solar system from SSM is available with the Jet-Flame to provide home energy for off-grid areas, capable of providing lighting, cell phone charging, and cleaner cooking.

George: How have consumers reacted to this new product?

Still: More than 100 samples have been distributed worldwide, with support from Global Good. There are currently five field test reports from Africa, Asia, and Central America, with positive early results. C-Quest Capital (CQC), a company engaged in carbon finance-enabled stove distribution, completed a pilot with 10 families in Malawi and found that the principal perceived benefits were speed of cooking and time savings, in addition to fuel savings of about five kilograms of wood per day.

We are excited about the potential for carbon credits from fuel savings to support a home energy makeover for off-grid families. The rocket stove, invented in 1982 by Dr. Winiarski at ARC, went viral and is used worldwide, but it needs to be cleaner-burning to protect health. Adding the Jet-Flame is a step in that direction.

George: What other organizations have contributed to the development and commercialization of the Jet-Flame, and in what ways?

Still: The project has been supported with funding from the U.S. Department of Energy, the U.S. Environmental Protection Agency (EPA), Global Good, the Clean Cooking Alliance (Alliance), the Osprey Foundation, and the Overlook Foundation. Beyond financial support, the Alliance and John Mitchell at the EPA’s Household Energy and Clean Air initiative have supported market contacts and strategy development. And Dr. Dan Lieberman at Global Good directed a major portion of the product development and supported the product launch.

Shen: SSM believes that clean cooking will be even more relevant in the future. The Alliance has done a great job of connecting potential clients with a stove manufacturing company like us. We wish to continue to work with the Alliance and to become better known in the world as a leading stove manufacturer.

George: What does your growth look like from here?

Shen: SSM has the ability to access investment capital based on its extensive track record and annual sales of one million stoves outside China and multi-million annual stove sales within China. Since 2019, SSM has invested US $4 million in a new, state-of-the-art stove manufacturing system. By 2021, SSM will have an export capacity of 2 million stoves per year.

Still: ASAT is sustained by various revenue streams and serves as a long-term partner in a number of ventures. There is a need for both risk capital and secured debt financing for project implementers and distributors like CQC. That’s where we see the funding gap currently. The early Jet-Flame results are promising, so we are working to support pilots and commercial scale programs in a range of countries