red sign with white letters reading Wood Burning Prohibited

Clean Burning of Biomass

red sign with white letters saying Wood Burning Prohibited

Scotland has banned the use of climate polluting home heating systems such as oil and gas boilers, and wood burning stoves (except in cases of need) in new construction. Heating homes creates one fifth of Scotland’s CO2e. The plan is to switch to electric heat pumps, hydrogen and tighter, better-insulated homes in an effort to achieve carbon neutrality by 2045. https://www.bbc.com/news/uk-scotland-68778757

Oil and gas (fossil fuel) burners create too much CO2. Burning renewably harvested biomass can emit close to zero CO2, but old stoves make too much black smoke which is ~2000 times worse for climate change compared to CO2 by weight.

Heating stoves that burn sustainable biomass cleanly enough to protect health and climate are starting to become available. Testing the new generation of stoves in use will show whether biomass can join solar, wind, and hydro as a useful renewable energy resource in the post fossil fuel era.

Maybe those red signs will become green?

Green sign saying Sure, Light Up

Aprovecho Announced as a Winner of the Wood Heater Design Challenge

The U.S. Department of Energy (DOE) Bioenergy Technologies Office (BETO), in collaboration with Brookhaven National Laboratory (BNL), Lawrence Berkeley National Laboratory (LBNL), and the Alliance for Green Heat, today announced the winning teams for the Wood Heater Design Challenge (WHDC). 

Aprovecho Research Center, from Cottage Grove, Oregon, came in second place and won $25,000 with a novel burn pot, airflow configuration, and sensor package for pellet heaters. Davidon Industries from Warwick, Rhode Island was awarded first place for their mechanically automated, combustion-air control technology for cordwood heaters. Kleiss Engineering from Cloverdale, Indiana, won the third-place prize with a smart wood stove heater.

“Embracing innovation allows us to challenge existing norms, push boundaries, and discover new solutions that can reshape the entire industry,” said Dr. Valerie Sarisky-Reed, Director of BETO. “Wood stove research is part of DOE’s overall strategy to develop affordable bioenergy technologies and convert our nation’s renewable resources into fuels, power, products and in this case, more efficient wood stoves for homeowners.”

Aprovecho, Davidon, and Kleiss were selected from nine teams competing at the Wood Heater Technology Slam in September 2022. Teams pitched new wood stove ideas to retailers, the public, and experts, who assessed which stoves were the most innovative, efficient, and offered the greatest market potential. The three finalist teams moved forward to the testing phase of the competition, which was held this past spring at BNL in Upton, New York.

Read the full press release on the DOE Website. Learn more about the BETO-funded Wood Heater Design Challenge.

Introducing Aprovecho’s New Executive Director, Dr. Nordica MacCarty 

Photo: Karl Maasdam/OSU Foundation

Aprovecho Research Center is pleased to announce that Dr. Nordica MacCarty has accepted the role of Executive Director. Dr. MacCarty takes over the position from Dean Still, who continues on as Research Director. Dr. MacCarty is also an Associate Professor of Mechanical Engineering at Oregon State University where she will continue teaching and directing the Humanitarian Engineering program as the Richard and Gretchen Evans Scholar of Humanitarian Engineering.

Nordica first came to Aprovecho in the summer of 2000, just after completing her BS in Mechanical Engineering at Iowa State University. She spent the summer testing and experimenting with Rocket Stoves, and attended the very first ETHOS Conference, which was held at the Aprovecho campus. “That summer changed my life and career goals” she said, “and my dream now is to help Aprovecho continue to bring accessible designs to improve lives well into the future.”

Prior to joining the OSU faculty in 2015, she spent nearly 10 years working for Aprovecho as an international consultant building capacity at projects and universities abroad for the design and testing of renewable household energy systems, and was a National Science Foundation Graduate Research Fellow. Dr. MacCarty holds an MS and a PhD in Mechanical Engineering from Iowa State. She serves as Associate Editor for the journal Energy for Sustainable Development and was recently recognized with the Elevating Impact Award for social entrepreneurship from the Lemelson Foundation and OSU’s 2020 International Service Award. She is also the lead PI on the $2.5 million US DOE grant recently awarded to the OSU and Aprovecho team to design cleaner cordwood heating stoves for US and international markets. (https://today.oregonstate.edu/news/oregon-state-receives-25-million-grant-create-wood-stoves-burn-more-cleanly )

The Aprovecho team feels that Dr. MacCarty is a valuable addition, due to her interests in understanding the relationships between energy, society and the environment, and engineering design applied to global humanitarian needs. “Nordica is my perfect replacement because she combines expertise from the field, the lab and academia” said Dean Still. “I couldn’t think about leaving without competent replacement, and I have zero doubts that she will do better than I did.”

Dr. Larry Winiarski

Remembering Dr. Larry Winiarski

Dr. Larry Winiarski
Dr. Larry Winiarski, 1940-2021

Dr. Larry Winiarski, the Technical Director of Aprovecho Research Center (ARC), died this past week at the age of 81. In the 1980’s and 90’s, Dr. Sam Baldwin defined how to improve heat transfer efficiency in biomass cook stoves (pot skirts, etc.), Dr. Tom Reed created the TLUD, and Dr. Winiarski invented the Rocket stove. The saying “We stand on the shoulders of giants” certainly applies to the stove community.

Larry led teams from ARC around the world starting in Central America, where the plancha stove was evolved, after he found that a floor tile called a baldosa made a long lasting and relatively low mass combustion chamber that was surrounded by wood ash, a great natural source of refractory insulation. Larry discovered that Rocket type stoves, like plancha stoves, can be described by ten design principles and that these simple engineering principles could be taught to indigenous people, mostly women, who were the experts in using the stoves. My memories of Dr. Winiarski, who was born in Nicaragua, are often about him having a wonderful time speaking Spanish as stoves were constructed and flavorful food prepared.

It is not an exaggeration to say that Larry had a heart of gold. He picked up sick kids and walked from the city dump in Managua to a distant hospital. He slept on cement floors for months at a time in Haiti. Larry lived as others lived in Africa for years and because of his character was loved and respected in villages worldwide. His Rocket stove found a place in people’s homes in the same way that Larry was cared for, accepted, and loved by strangers. Larry is missed by thousands of friends and he was blessed with a life well lived.

There will be a Celebration of Larry’s Life on Saturday, August 28, 2021 at 1:30 PM, at Colgan’s Island, 79099 Hwy 99 N in Cottage Grove, Oregon.

New Climate Change and Biomass Combustion Study Wins Osprey Foundation Support

Aprovecho Research Center is pleased to announce that it has just been awarded a $50,000 grant from The Osprey Foundation in support of expanding research into the connection between biomass combustion and climate change.

To date, a handful of lab and field studies have resulted in relatively little information on how stove/fuel interventions could impact emissions. The Gates funded GH Labs has partnered with us in this project because information is vitally needed to make sure that stove interventions are most productive.

Research has identified renewable biomass as carbon neutral but only when burned without making climate forcing emissions.  Aprovecho manufactures and sells the Laboratory Emissions Monitoring System (LEMS) as a tool to characterize cook stove performance. The LEMS enables ARC to develop stoves addressing climate, health, and effectiveness. It has become the centerpiece of more than 60 cookstove laboratories worldwide.

The LEMS measures thermal efficiency and the emissions rates of PM2.5, CO, CO2, and Black Carbon. Minimizing those emissions is important for addressing climate change and protecting human health. The effectiveness of the stoves is assured when cooks are deeply involved in designing them.

Non-methane hydrocarbons (NMHC) and methane contribute to a significant fraction of the global warming potential, especially from charcoal burning stoves, but to date have not been measurable with the LEMS.

The Osprey Foundation sponsored project goals are:

  • Adding the measurement of methane and NMHC to the LEMS.
  • Surveying the global warming potential of wood burning stoves and charcoal stoves and creating market driven designs that address climate/health/effectiveness.
  • Widely distributing open source information (including CAD drawings) describing how to minimize climate forcers in biomass stoves.

At the Leaders Summit on Climate hosted by President Biden, the U.S. government pledged to help countries achieve their climate ambitions through expanding access to clean cooking. We feel very lucky to be investigating how to manufacture improved biomass stoves that cook well, are affordable, and protect personal and planetary health. Thank you, Osprey Foundation!

Ten-fold Increase in Carbon Offset Cost Predicted

Prices of carbon credits used by companies to offset their emissions are currently low, due to an excess of supply built up over several years.

According to recent research at the University of London, without the excess supply, prices would be around $15/tCO2e higher, compared to $3-5/tCO2e today. (tCO2e means tonnes of carbon dioxide equivalent, “carbon dioxide equivalent” being a standard unit for counting greenhouse gas (GHG) emissions.)

The paper predicts that the surplus will not last forever, with demand for carbon credits expected to increase five to ten-fold over the next decade as more companies adopt Net Zero climate commitments. This growth in demand should see carbon credit prices rise to $20-50/tCO2e by 2030, as more investment is required in projects that take carbon out of the atmosphere in the long-term. With a further increase in demand expected by 2040, carbon credit prices could rise in excess of $50/tCO2e.

Guy Turner, CEO of Trove Research and lead author of the study said “It is encouraging to see so many companies setting Net Zero and Carbon Neutral climate targets. What this new analysis shows is that these companies need to plan for substantially higher carbon credit prices and make informed trade-offs between reducing emissions internally and buying credits from outside the company’s value chain.”

Imagine the stoves that could be supported by a $20 price for an avoided tonne of carbon dioxide. Stoves with good thermal efficiency can save three tonnes or more per year making long lasting, super clean stoves with chimneys a great deal for carbon developers and investors.

And a great deal for consumers.

Report: https://trove-research.com/wp-content/uploads/2021/06/Trove-Research-Carbon-Credit-Demand-Supply-and-Prices-1-June-2021.pdf

Outstanding Accomplishments

In addition to the recent Tibbetts Award, ASAT has just received EPA recognition for our success. ASAT (the for-profit arm of ARC) was awarded a 2021 EPA Administrator’s Small Business Program Award for Outstanding Accomplishments by a Small Business Contractor. This award recognizes ASAT’s contributions in Fiscal Year 2020 and our efforts to promote EPA priorities of protecting human health and the environment.

ASAT Inc. staff pose with their Tibbetts Award. From left to right: Sam Bentson, David Evitt, Jill Allen, Dean Still, Kim Still, and Dr. Nordica MacCarty.

EPA SBIR funding enabled ASAT to research and develop commercially viable inventions. We developed the Integrated Stove (seen below) that includes stand-alone accessories including the Jet-Flame www.Jet-Flame.com, an air cooled thermoelectric generator, and an electrostatic precipitator that reduces emissions of smoke from chimneys.

The Integrated Stove with Air Cooled 20 Watt TEG Prototype.
A woman sits next to two rocket stoves.

More Good News from C-Quest Capital (CQC)

A woman sits next to two rocket stoves.
Firewood is stored between a pair of CQC’s TLC Rocket Stoves.

C-Quest Capital recently announced a collaboration with Macquarie Group Ltd., a financial services company with A$550 billion in assets under management and 16,000 employees in 35 countries. The two firms will fund and deploy efficient cook stoves with pot skirts to one million rural households across Malawi, Zambia and Tanzania. CQC’s preferred rural stoves project standard is two stoves per household to decrease user fallback on three-stone fires.

USAID in-field testing in Africa showed that Rocket stoves with pot skirts reduced smoke emissions by 40% due to the use of less wood while cooking. Addressing health by increasing the air exchange rate in the kitchen and home is a fundamental component of this project. This is done by strategic placement of windows and doors, and promoting half-wall kitchens or well-protected external cooking spaces. A minimum of one visit per year by trained staff to each household to help repair, maintain, and ensure good use of the Rocket stoves is also essential to elevating adoption rates in the targeted areas.

Over the next decade, this investment will deliver over 40 million high quality carbon credits with verified Sustainable Development Contributions to the Voluntary Carbon Market. It is the first leg of a three-pronged program to transform the lives of low-income communities across Sub-Saharan Africa at scale. Ken Newcombe, CEO of CQC, comments, “Our hope is to include something like 100,000 Jet-Flames, assembled by Ener-G-Africa in Lilongwe, Malawi, in the project. Field tests have indicated that the Jet-Flame dramatically reduces PM2.5 emissions and exposure to cooks and their families, further protecting health. If the deployment doesn’t get to 100,000 sold by end of next year it’s not because of the demand – it’s because we couldn’t get the working capital and distribution channels to get the product to the market. Of course, we are exploring all possibilities.”

Manufacturing pot skirts

C-Quest Capital and Ener-G-Africa Launch Major Jet-Flame Project

In 2013, C-Quest Capital (CQC) began distributing and installing the TLC Rocket Stove (TLCRS), a high-efficiency, long-life metal and brick improved cookstove, to the rural poor of Malawi. Early learning has resulting in many upgrades to the stove to improve sustained use and a long life. Over the past two years, CQC has installed the TLCRS in 450,000 Malawian households. Beginning in January 2020, Ener-G-Africa (EGA), a Malawian entity formed by CQC and Malawian entrepreneurs, began manufacturing all the metal stove parts for CQC’s sub-Saharan Africa TLCRS program and has since produced more than 300,000 sets of parts.

Interior view of EGA Stove factory in Lilongwe, Malawi
Stove Kits ready to ship at Ener-G-Africa’s factory in Lilongwe, Malawi

More recently, in February 2021, CQC placed irrevocable orders for the first 10,000 Jet-Flames from Shengzhou Stove Manufacturer in China, marking the first large scale commercial commitment to Jet-Flame distribution in the world. With CQC’s funding, EGA’s factory in Lilongwe is currently building the second solar panel assembly plant in sub-Saharan Africa and will begin manufacturing the solar panels, and eventually the batteries, needed for the Jet-Flame Kit.  CQC is hoping the superior cost and cooking amenity provided by the Jet-Flame will make serious inroads to the charcoal user market.

Through the growing partnership between CQC and EGA, the TLCRS will be installed on a two stove per household basis in three million households across eight sub-Saharan African countries in the next four years. Together, CQC and EGA are setting a new standard for cookstove projects in rural Africa. 

Manufacturing pot skirts
Welded pot supports
Parts ready for packing
Manufacturing area at Ener-G-Africa’s factory in Malawi

A New Edition of “Clean Burning Biomass Cookstoves”

cover of Clean Burning Biomass Cookstoves 2nd edition
Click here to download the free pdf files

If stoves pollute in the lab, they certainly will in the field. We estimate at least 3 times more. Commercially available biomass cookstoves that meet WHO standards are very rare. ARC continues to be committed to doing research and development to help to get the needed new stoves to market so that field studies will show success in sales, protecting health, saving wood, and making cooks happy. We believe that sharing what we learn is very important! So, we updated our “textbook” and it’s available for free here. The chapters have been updated and rewritten to try and share everything that we have learned in the lab in the last five years.

Enjoy!

Here are some highlights:

  • With clean outdoor air, doubling the air exchange rate halves the concentrations of PM and CO in the kitchen.
  • Using an EPA model of Oakridge, Oregon, the outdoor air concentration of PM2.5 would only be increased from 13.1 μg/m3 to 13.3 μg/m3 if homeowners used an ISO Tier 4 PM2.5 cooking stove.
  • A catalytic converter works well with gases (30-95% reduction of CO) but not with smoke (30-40% reduction of PM2.5) (Hukkanen et al., 2012).
  • We think that the Harris TLUD is perhaps the first “close to optimal” cookstove. It scored 0.7mg/minute PM2.5 with pellets at Lawrence Berkeley National Laboratory. It has a 3 to 1 turn down ratio. Large natural draft static mixers create thorough mixing. Decreasing primary air reduces the rate of reactions (production of wood gas) if the air/fuel mixture becomes too rich. A stationary fan blade spins the flame for longer dwell time. And cooks at ARC love to use it.
  • When carefully tested at ARC, the SSM Jet-Flame in the CQC earthen stove scored Tier 4 for thermal efficiency, CO, and PM2.5.
  • Renewably harvested biomass can be a carbon neutral energy source when burned very cleanly.

We are getting closer to practical solutions! The ones we know about are in the book.