Tier 4 Cookstoves: Developing five new clean burning biomass cookstoves RECENT DEVELOPMENTS FROM THE DOE PROJECT

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1 Tier 4 Cookstoves: Developing five new clean burning biomass cookstoves RECENT DEVELOPMENTS FROM THE DOE PROJECT

2 Overview 1.) With DOE funding ARC evolved five Tier 4 cookstove prototypes using the WBT and the LEMS emission hood. 2.) The ND-TLUD, ND-Rocket, ND-Charcoal, FD-Side Feed, and FD-Top Feed scored frequently in the ISO/IWA Tier 4 ranges. They are on the ARC table in the lobby. 3.) The stoves were field tested with the CCT/LEMS at RTKCs in Ghana, Senegal, India, Nepal, Kenya, Honduras, Peru, and China. The CCT data from field tests was used to refine the designs. We want to manufacture the FD-Side Feed stove. 4.) An article in EcoHealth (2015) and book Clean Burning Biomass Cookstoves (2016) summarize the findings. 5.) You can buy the book here at ETHOS.

3 Improving the FD Side Feed Stove New R&D: Chimney: needed to meet new WHO Indoor Air Guidelines No more stoves without chimneys? Flat top cooking option Thermal efficiency is only 26% but was desired by consumers. Submerged pot is 55% but can only use one pot. Auto-damper Automatically diverts smoke up the chimney when the pot is removed. Catalyst Improved thermal efficiency to 55% and lowered PM2.5.

4 Up and down on the IWA metrics: More work needed

5 The FD Side Feed stove The FD- Side Feed Stove burns sticks of wood, bundled grasses, (found fuel) fed horizontally into the combustion chamber. Attempts at using FD jets of secondary air above the fuel reduced PM2.5 to around 150 (mg/mjd)in the lab. High velocity jets of FD primary air coming up from below the fuel were more successful and lowered PM2.5 to around 30 mg/mjd. This technique is also less expensive to manufacture. Backdraft was reduced by 1.) decreasing the size of door 2.) The diameter of the internal Rocket chimney is 10cm, not smaller 3.) The sticks of wood are close to the bottom of the combustion chamber. The hot gases flow in a 6mm channel gap up the sides of the pot and then flow all the way down to heat the external walls of the combustion chamber. 750C to 800C gases contact the pot and a catalyst gets hot near the combustion chamber resulting in 55% thermal efficiency. The hot gases have a measured velocity of around 3 meters/second compared to around 1 meter/second for the ND Rocket stove.

6 Pathway to Sales? Prototypes were made at Shengzhou Stove Manufacturer resulting in cost estimates as the development process continued. The FD Side Feed Stove was generally the most popular in field tests. Willingness to pay ranged from $5 to $40. The clean burning wood stove market is challenging. Traditional stoves can be free or inexpensive. Selling the Tier 4 cookstove means offering the consumer a novel, expensive, and challenging (but we hope exciting) product. We hope that placing the FD Side Feed stove in the context of a box store, full of hundreds of new, aspirational products, will lead to a sustainable business. No one goes broke! But, the field tests strongly indicate that the stove has to sell for $40 or less!

7 New Book Summarizes DOE Project Clean Burning Biomass Cookstoves explains the technical advances used in the five stoves. CAD drawings in the book are helpful when manufacturing the stoves. The book includes chapters on: Iterative Stove Development and Modelling Testing Cook Stoves Stoves as a Health Intervention Improving Heat Transfer Efficiency Improving Combustion Efficiency A Survey of Clean Burning Cookstoves Proyecto Mirador: The Business of Stoves ARC and Stove Dissemination Chapters on the five stove designs

8 Next Steps ARC is continuing to improve the heat transfer, combustion efficiency, and turn down ratio in the FD Side Feed stove. We are learning from the experts at Shengzhou Stove Manufacturer how to lower costs to meet the $40 retail price. We hope to sell the Tier 4 stove through a US based distributor with hundreds of stores in developing world markets. We look forward to working with Professor Nordica MacCarty (OSU) to understand the 55% thermal efficiency in the FD Side Feed stove. ARC estimates that the PM2.5 of the FD Side Feed stove will be around 10mg/min in real use. We want to reduce the real use PM2.5 to around 4mg/min before manufacturing. Faster jets of primary air? We are starting to help stove projects to design and manufacture Tier 4 stoves. ARC/BUCT looks forward to 150 million Tier 4 stoves being made in China by the Chinese government.