The Estufa Finca Farm Stove is a top-lit updraft (TLUD) micro-gasifier cookstove that can create biochar from a wide range of dry organic input materials. The biochar produced from the stove can be used as a soil amendment to increase soil health and improve agricultural yield. When used as a soil amendment, the biochar produced from the stove also acts to sequester carbon that would otherwise be released to the atmosphere. A promotional video highlights the stoves biochar applications during implementation with rural farmers in Costa Rica.
Video available on how to use the Estufa Finca.
SDG 7: Affordable and Clean Energy
SDG 3: Good Health and Well-Being
Market Suggested Retail Price
Target Users (Target Impact Group)
Distributors / Implementing Organizations
For 2015, it was mass produced by SeaChar in the United States, also produced by local micro-businesses in Costa Rica. The Estufa Finca stove is constructed from common materials available in developing countries: a 20 liter (5 gal) combustion chamber made from a metal bucket, surrounded by a shroud formed from galvanized roofing. Fabrication consists of cutting rebar, cans, buckets and shroud materials; drilling holes; snipping tin and de-burring and grinding rough metal edges. Stove assembly consists of fastening stove components with rivets, bolts, and screws. A photo design guide describes manufacturing methods in detail.
Intellectural Property Type
User Provision Model
For 2015, users could order the stove from SeaChar online, or from a distributor in Costa Rica. Users can also fabricate the stove using basic tools and materials following the design guide. For 2018, contact SeaChar on their facebook page.
Distributions to Date Status
A wide variety of dry biomass including sticks, bamboo, coconut shell, cacao chaffe, etc.
Thermal efficiency (%)
PM emissions (g/MJ delivered to pot)
CO emissions (g/MJ delivered to pot)
Time to boil (min/L)
Design specifications include a 19 litres (5 gallons) capacity combustion chamber surrounded by a shell of galvanized roofing and an air base with primary air damper to control intake required for a different biomass feedstock removable cooktop. TLUD stoves can accept a variety of dry, woody biomass as fuel. See the GIZ 2013 publication on Micro-gasification for information on size, type, and preparation of appropriate fuels. An additional stove setting structure is recommended to provide a stable and protected platform to house the stove and bring the cooking surface to a desirable height for cooking.
Manufacturer Specified Performance Parameters
According to SeaChar:
- The product creates high quality biochar from a wide range of dry organic input materials.
- Each pound of durable high carbon charcoal removes three pounds of atmospheric carbon from the carbon cycle.
- Biochar stores captured carbon in soils for thousands of years, making this a unique carbon negative energy technology.
Vetted Performance Status
Approvecho Research Center testing results revealed an average emissions profile of 8.24 g CO/kg of dry fuel consumed and 0.18 g PM/kg of dry fuel consumed. Approvecho Research center projects an 83% reduction in Co and a 91% reduction in PM if the Estufa Finca Stove uses the same amount of fuel as a traditional 3-stone fire. In an effort to standardize cookstove performance an International Workshop Agreement (IWA) was established in 2012. The IWA created tiers of cookstove performance in order to communicate technical information more easily to the government, donors, investors, and consumers when making decisions. However, many manufacturers have not tested stoves using the newly adopted IWA performance metrics. See the Global Alliance for Clean Cookstoves for more information.
For 2018, when purchased through SeaChar, detailed instructions on safe stove operation are provided. Wooden handles allow the stove to be handled when hot.
Complementary Technical Systems
Academic Research and References
Anderson, P (2015). Origins, History and Future of TLUD Micro-gasification and Cookstove Advancement. Version 1.2.
Global Alliance for Clean Cookstoves. 2013. Interim Reporting Requirements for IWA Tiers of Performance. cleancooking.org. Global Alliance for Clean Cookstoves.
SeaChar. n.d. www.facebook.com.
Roth, Christa, Paul Anderson, Hugh McLaughlin, Thayer Thomlinson, and Kelpie Wilson. 2014. Micro-Gasification: Cooking with Gas from Dry Biomass. Edited by Heike Volkmer. www.bmw.de. Eschborn, Germany : Deutsche Gesellschaft für Internationale Zusammenarbeit (GIZ) GmbH.
Bradley, Kirsten. 2013. Making Biochar: Building Our First Dome School Biochar Stove. Milkwood: Permaculture Courses, Skills + Stories. March 10, 2013.
SeaChar. 2012. SeaChar Estufa Finca Project. seachar.org. SeaChar.
Hatfield, Mike, Ryan Thompson, and Sam Bentson. 2010. Testing Results of Estufa Finca. Stoves.bioenergylists.org. Oregon, USA: Aprovecho Research Center.
Aprovecho Research Center- Testing and Improving Biomass Cookstoves. n.d. Aprovecho.
International Standards Organization (ISO). 2012. Foreward ISO – International Workshop Agreement IWA 10. Cleancooking.org. ISO, Partnership for Clean Indoor Air (PCIA), Global Alliance for Clean Cookstoves.
Global Alliance for Clean Cookstoves . 2014. The Water Boiling Test (Version 4.2.3): Cookstoves Emissions and Efficiency in a Controlled Laboratory Setting. www.1library.net. Global Alliance for Clean Cookstoves.
Compliance with regulations
Water Boiling Test (WBT)
Details on the 2010 pilot can be found in the project report. Recipient of a grant from National Geographic's Great Energy Challenge initiative. A summary of how micro-gasification stoves work is provided by SeaChar and can be found here.