MIT D-Lab students and instructors are improving the effectiveness and economy of a brooding technique for newborn chicks that utilizes a practical, local resource: beeswax.
Developed through participatory design with farming partners in Cameroon, the Off-Grid Brooder is a solution aimed at improving the profitability of small and medium-sized poultry farms in the African country. The invention may also help farmers get some sleep, as small-scale farmers in areas with poor electricity supply typically build bonfires overnight to keep their chicks warm.
“The goal is eight hours. If farmers can maintain warmth for eight hours, they can sleep,” says Ahmad (Zac) Zakka SM ’23, a D-Lab instructor and former student who traveled to Cameroon in May to work on implementing improvements to the brooder that were tested at D-Lab, along with D-Lab students, collaborators from African Solar Generation (ASG), and the Swiss African Diaspora Council–Cameroon Chapter (CDAS–BC).
Poultry farming is concentrated in low- and middle-income countries, where it is an important component of rural economies and provides residents with a cheap source of protein. However, raising chickens comes with economic risks, mainly because it is difficult for smallholder farmers to keep newborn chicks at a viable temperature (33-35 degrees Celsius or 91-95 degrees Fahrenheit, depending on their age). After feed costs, the largest input for rural poultry farmers is the firewood used to heat the chick spaces.
According to D-Lab researchers, the average smallholder farmer in Cameroon who employs traditional brood-raising methods spends $17 a month on firewood and achieves a 10 percent profit margin, but can also suffer mortality rates that wipe out entire chicks due to overheating or insufficient heating.The off-grid brooder is designed to replace open fires with cheap, renewable and locally available beeswax (a phase-change material used to make thermal batteries).
ASG initially developed the SolarBox, a brooder technology that used photovoltaic panels and batteries to power incandescent light bulbs. This provided effective heating, but was prohibitively expensive and difficult to maintain. In 2020, students in the D-Lab Energy class took on the challenge of reducing the cost and complexity of the SolarBox heating system and making it accessible to smallholder farmers in Cameroon. Through participatory design (a collaborative approach that involves all stakeholders in the early stages of the design process), the team discovered a unique solution. Beeswax stored in used glass containers (such as mayonnaise jars) is fired in a double boiler to melt, then attached inside an insulated brooder box next to the chicks. As the beeswax cools and hardens, it releases heat for several hours, keeping the brooder within the temperature range required for chick growth and development. Farmers can then recharge the cooled beeswax batteries and repeat the process as many times as they like.
“The big challenge was how to get the heat,” says D-Lab research scientist Daniel Sweeney, who co-teaches two D-Lab classes with Zacca: 2.651/EC.711 (Introduction to Energy in Global Development) and 2.652/EC.712 (Applications of Energy in Global Development). “Decoupling the heat provided by the biomass (wood) from the heat needed by the chicks in the brooding boxes at night is the core of the innovation here.”
D-Lab instructors, researchers and students have been testing and tweaking the system with partners in Cameroon. The lab box, built during D-Lab’s visit to Cameroon in January 2023, worked well but was “very expensive to build,” Zakka says. “The lab box was a proof of concept in the field. The next step was to figure out how to make it affordable,” he continues.
During D-Lab’s visit to Cameroon in January 2024, a new brooding box made entirely from locally sourced recycled materials was developed, at 5% of the cost of the research prototype. Designed and built in collaboration with CDAS-BC, the new brooding box is much more affordable, but its functionality still requires some fine-tuning. From late May to mid-June, the D-Lab team led by Zakka worked with their Cameroonian collaborators to refine the system again, this time evaluating the effectiveness of insulating the brooding box with panels of straw, a readily available, low-cost material.
The MIT team will host CDAS-BC and include the school’s president and founder, Carol Elman Meng, and secretary/treasurer, Kathleen Wich, who run an organic chicken farm in Afambashi, Cameroon. “The students will carry out experiments with the boxes and improve their insulation, keeping in mind that chicks need ventilation,” they say.
Additionally, the CDAS-BC partners say they also want to explore ways to increase the number of chicks that can be warmed in the boxes: “If the system could warm 500-1,000 chicks at a time, farmers could save on firewood, sleep through the night, and minimize the risk of fires in the building and of stepping on chicks while changing firewood,” they say.
Earlier this spring, Erleman Mengwe and Wich tested a low-cost, off-grid brooder box that, in its current design, can house 30 to 40 chicks.
“They were very interested in partnering with us to evaluate the technology. They’ve been running tests and taking a lot of technical measurements to track temperatures in the brooders over time,” Sweeney said, adding that CDAS-BC’s partners are accumulating datasets and sending them to the MIT D-Lab team.
Sweeney and Zakka, along with Ali Kombaagui, a doctoral student who worked on the research box in Cameroon last year, hope to not only improve the functionality of off-grid chicken farms but also expand their use outside Cameroon.
“The goal of this trip was to make a working prototype, and the goal since then has been to scale this up,” Combergi said. “This is definitely scalable.”
“This technology could be used throughout the developing world in the small-scale poultry sector,” agrees Zacca, who says D-Lab’s visit this spring included a workshop teaching local poultry farmers about the benefits of off-grid brooders and how to build their own.
“I’m excited to see if people are interested in pursuing this as a business and if they’ll build it and sell it to other people in the area,” Zacca said.
Sweeney added: “It’s not rocket science. We’re confident that with the guidance and open-source information we can share,[farmers]can do it themselves.”
He says partners identified through MIT’s network in Zambia and Uganda are already building their own brooders based on D-Lab’s designs.
The Abdul Latif Jameel Institute for Water and Food Systems (J-WAFS), which supports research, innovation, and interdisciplinary collaboration on water and food systems, awarded the Off-Grid Brooders project a $25,000 research and development grant for 2022. The program was “pleased that the project’s approach was based on engagement with MIT students and local collaborators,” said executive director Renee Robbins. “The participatory design process helped create an innovative prototype that is already having a positive impact on small-scale chicken farmers.”
That process and the very real impact on communities in Cameroon is what attracts students to the project and makes them so committed.
Sweeney says a recent D-Lab review of the brooder design revealed that the project continues to capture the attention and curiosity of students who got involved in the early stages and still want to get involved.
“There’s something special about this project. There’s a cohort of students who are still actively working on a wide range of projects,” he says. “There’s something special about it.”
