Report on the 2011 ETHOS Stoves Conference

By: Kelpie Wilson

For the third year, IBI attended the annual conference sponsored by ETHOS (Engineers in Technical and Humanitarian Opportunities of Service) held in Kirkland, Washington, USA on January 28-30, 2011, to learn about new developments in clean cookstoves, including pyrolytic and gasifier stoves that can produce biochar.

Cheryl Weyant of the University of Illinois presented results from field testing of stove emissions in Honduras, Nepal, and Uganda, using an easily transportable probe. Comparing several stove types, a forced air gasifier stove proved to be cleaner than other stoves with far less production of the atmosphere-warming black carbon particles known as soot.

Dr. Paul Anderson gave an overview of TLUD (Top-Lit Up-Draft) gasifier stoves and announced a series of upcoming Combined Heat and Biochar (CHAB) workshops scheduled for various locations around the world.

Marc-Antoine Pare of Georgia Institute of Technology presented his work on rice husk gasifiers at Dr. Paul Oliver’s ESR Ltd. research lab in Vietnam. Because rice husk is high in silica, it is difficult to combust completely to ash. As a consequence, rice husk gasifiers tend to produce large amounts of biochar. As an abundant waste material in many parts of the world, rice husk has good potential to provide clean energy for cooking and other uses while producing biochar. Click here to view Marc’s presentation and other work.

Nathanial Mulcahy of World Stove gave a technical presentation on his pyrolytic Lucia stove. Mulcahy described his stove as TLOD (Top Lit Opposite Draft) technology and he listed several ways that it differs from generic TLUD designs: there is no flow through the combustion chamber; thermal conductivity in the combustion chamber is required to heat the fuel; close tolerances and precise spacing of the combustion chamber holes are needed to tune the gas flows in the device; the stoves must be tuned for specific feedstocks. If a TLOD device is not tuned properly, it can still work, but will function more like a conventional TLUD. Mulcahy gave another presentation on the Stove Hub manufacturing centers World Stove is establishing in several countries. The Hubs manufacture stoves and distribute pellet fuels to stove users in exchange for the biochar produced. Biochar is stored in a warehouse, where it is audited and a carbon payment is sent to the stove manufacturing hub. Biochar is then tested and incorporated in the soil.

The big topic of discussion at ETHOS 2011 was the progress of the Global Alliance for Clean Cookstoves program announced by the Clinton Global Initiative last September. The goal of the effort is for 100 million homes to adopt clean and efficient stoves and fuels by 2020.

The Alliance, managed by the UN Foundation, will provide $100 million over 5 years to promote clean cookstoves by accelerating stove research and development, creating standards, supporting advocacy and public education, and partnering with manufacturers. The US government has committed to providing $50 million and the US Environmental Protection Agency and the US Department of Energy will be involved in the R&D effort. Many of the cookstove experts serving on various technical committees advising the effort were present at the ETHOS conference and some had just come from a meeting with the US DOE. There was speculation about which DOE lab might manage the R&D program.

For the first time, top notch combustion and materials science will be applied to the problem of clean, efficient stoves for the world’s poorest people.  In January, United Nations Secretary-General Ban Ki-moon announced that 2012 will be the International Year for Sustainable Energy for All. He called for a “clean energy revolution” and said this is essential for minimizing climate risks, reducing poverty, improving global health, empowering women and meeting the Millennium Development Goals for global economic growth, peace and the health of the planet. With biochar-producing stoves, it will be possible to add restoration of degraded soils, increased food security and carbon sequestration to this list.