WorldStove is a nonprofit organization that produces clean cookstoves that use pyrolytic gasification to reduce indoor air pollution and is working with communities to distribute these stoves around the world. These stoves use waste biomass as fuel, reducing the broader environmental impacts of wood fired cooking. According to the World Health Organization, 4.3 million people die each year as a result of air pollution attributable to cooking fires. In addition, there is a significant environmental toll caused by deforestation and carbon emissions caused by fuel used on these cooking fires. Food Tank recently had the opportunity to interview Nathaniel Mulcahy, founder, and owner of WorldStove, about how these stoves can be adapted to local community cooking cultures and support local economies, whilst also reducing emissions.
Food Tank (FT): Your company can adapt stoves to the needs of different cultures. Can you share with Food Tank readers some examples of these adaptations and tell us how communities have responded to your stoves?
Nathaniel Mulcahy (NM): Food is much more than nutrition. Culinary traditions build communities, strengthen families, and can make friends of strangers. In refugee settings, many have lost their home, their belongings, and in some cases even their families. For those people, culinary traditions may be the only thing they have left, the only thing that can not be stolen from them and this is where we try to make a difference.
Too often stove providers are focused on the water boiling test, where boiling a liter of water as fast and as efficiently as possible is the key focus. From engineering and environmental perspectives these are worthy goals, but what good are they if the stove that can boil a liter of water in record time can not be used to cook the dishes that are core to who you are? For this reason, when we start a new program, in nonemergency situations, we first go in and spend weeks working with the local community. We hire cooks and have them teach us to cook all the most important local dishes on their preferred stoves and with their preferred pots.
Working this way serves many important functions:
1) We do not arrive as the experts to tell people how to do things but we come as students, thereby empowering local cooks and giving communities a critical role in development.
2) We learn what parameters are vital to making the dishes that are central to that community’s culture.
3) We eat many delicious and wonderful new foods.
After this phase, we then tune our stoves to meet the needs of a particular culture and community. We then return with the modified stoves, again hiring local cooks to try cooking the same dishes on our stoves. If they are pleased, we begin production locally, if not, we adjust and repeat as often as needed. Of course, high efficiency and low emissions are key design drivers for us, but if the stoves are to be successful, the people doing the cooking will have to want to use them.
Examples of adaptations we have made include the LuciaStove for Ethiopia, which cooks at a very high temperature for 40 minutes and has an incorporated mittard (like a clay griddle). The same LuciaStove tuned for Zambia cooks at a medium temperature for 2.5 to 3 hours and is adapted to work best with round bottom pots.
Perhaps the most challenging adaptation we’ve had to make was for northern Burkina Faso. We had tuned the stove to use the locally available waste biomass (karite shells, left over from the production of shea butter) and to meet the requirements of all the local dishes, including variable temperature settings. We’d even made the stove run without the need for constant refueling, as we had done elsewhere as a labor savings option. As a crowning achievement, we developed a snorkel system so the stove could function when in the ground (required for a local cooking technique using a long stand up stirring staff). We felt sure that we had done a good job, but we had made a critical oversight. An essential part of the culture is feeding fuel to the stove. Cooking in this region is a collective process. Women sit in a circle surrounding the fire as one woman stands to hold the stirring staff. Each woman takes turns adding small bits of twigs to keep the fire going at the right temperature. By making a stove that required no refueling we were placing at risk a critical part of bringing the community together for exchanging information and socializing. We then redesigned the stove, one more time so that that fuel could be added at any time, and those stoves have been in use ever since.
FT: One of WorldStove’s objectives is to create local jobs and improve local economies. Can you tell us how your company works to achieves this objective?
NM: This is a primary objective of WorldStove. Rather than distribute stoves, we help local communities establish their stove factories. The income to support the factory and supplies comes from the sale of pellets (the production of which is part of the stove factory) and the return of carbon offsets. In this way, the stove hubs are usually self-sustaining within 18 months. WorldStove is the first company certified as carbon negative and, we did so by creating a new offset program. What is unique about our offsets is that they are measurable to one-tenth of a gram, verifiable with GPS tags, and (in contrast to all other offset programs) 100 percent of the revenue generated goes to the local communities running the programs. All fees and certification costs are paid for by WorldStove as part of our social entrepreneurship program.
FT: Can you explain to Food Tank readers how your stoves reduce emissions? Are there additional environmental improvements for communities that use your stoves?
NM: There are two primary ways our stoves reduce emissions. The first is that LuciaStoves are tuned to maximize efficiency using pellets locally made of waste biomass. Rather than burn the pellets, the stoves extract gasses from the pellets and burn only those gasses. While burning solids, there are many differing processes taking place during combustion. However, by focusing only on the gas produced we can increase combustion efficiency, reducing black carbon emissions to the point that when Environmental Protection Authority first tested our stoves, they had to re-calibrate because several of the readings were too low to record.
The second way we reduce emissions is by the process LuciaStoves extract gas from waste biomass. Rather than have the gasses rise directly into the flame, they first pass down through the biomass and biochar, which acts as a filter to the gasses, before mixing with air and subsequent combustion. The process itself has the added benefit that it bonds soluble nitrogen to the biochar. Typically nitrogen volatilizes, but the reverse air flow causes it to bind to the char making the biochar a nutrient source for agriculture.
As for additional environmental improvements for communities that use our stoves, the most important environmental advantage is that in each community we tune our stoves to run on the locally available waste biomass. Most waste biomass is too high in minerals and too small to be used in traditional stoves and most often is left to rot releasing stored carbon dioxide back into the atmosphere. Alternatively, it is burnt in large heaps to avoid having waste issues. For example, Egypt alone produces 30 million tons of agricultural waste a year, and burning rice straw emits 80,000 tons of carbon dioxide annually. By tuning our stoves to only work with waste material not only do we avoid having waste become an environmental problem but we eliminate the need to cut trees for fuel (after all trees have already done an excellent job of sequestering carbon, might as well let them keep it for us.)
FT: Your stoves produce biochar through the cooking process. How can biochar support soil regeneration?
NM: The food we eat, the water we drink, and indeed much of the life on this planet is dependent on soil. To some degree, soil is one of our planet’s most critical bank accounts, and since the dawn of modern industrial agriculture, we, as a species have been making withdrawals and never any deposits. Soil carbon is now 34-50 percent lower than it historically was.
By producing biochar, we can reduce emissions and provide a way to help restore soil carbon. To avoid the temptation of burning the biochar we created an economic incentive through the offset program and used the biochar in aliquots, as part of our reforestation and agricultural programs. Thanks to biochar, we’ve even been able to grow tomatoes in desertified areas like Senegal and Northern Haiti, using 10 percent of the water needed in loamy soils. By making it possible for plants to grow in desertified areas, we begin the process of reestablishing a fertile, carbon-rich, topsoil.
FT: What do you see as the key opportunities and barriers for your company over the next five years?
NM: Key opportunities are from ongoing research and development and our latest products. Years in the making they help meet other critical needs. For example, one of our latest stoves, the LuciaClearwater, captures residual heat generated during cooking and uses it to run a three stage water purification process. As a result, with each meal cooked the stove can produce up to 11 liters of clean water starting from nonpure water, salt water or even urine.
In Burkina Faso we worked in a community where the average household spends $3 per day on fuel for cooking but only $0.05 per day per household for food, forcing many to have to make the terrible choice of buying food or the fuel needed to cook the food. Another of our latest innovations hits closer to home, as this tragic situation exists even in Massachusetts. In 2012, 238,000 households in Massachusetts (more than one million people) reduced the number of meals they ate to one or less per day during the heating season as they could not afford both food and the fuel needed to keep their homes from freezing. Realizing that our stoves were helping resolve this problem in developing nations we thought they might be able to do the same in Massachusetts. We subsequently developed a heating unit that uses the LuciaProcess to heat homes with waste biomass. As a side note, it is interesting to note that the average American lawn produces enough waste biomass per year to generate 130 percent of the heating requirements of the average American home.
As for barriers over the next five years, to meet ever growing demand, we’ve had to move three times to ever bigger shops and factories. With the latest products, it looks like we will have to do so again. A challenge for sure, but a good problem to have.
