Final Report: Design and Development of a Low Cost, Multifunction, Regionally Appropriate Solar Oven for Developing Countries in Latin AmericaEPA Grant Number: SU831889
Title: Design and Development of a Low Cost, Multifunction, Regionally Appropriate Solar Oven for Developing Countries in Latin America
Investigators: Carrano, Andres , Allam, Otman El , Bates, Josh , Fulton, Emma , Plaz, Carlos , Privorotskaya, Natasha , Steiner, Jonathan , Thorn, Brian , Wood, Christopher
Institution: Rochester Institute of Technology
EPA Project Officer: Nolt-Helms, Cynthia
Project Period: September 15, 2004 through May 31, 2005
Project Amount: $10,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2004) RFA Text | Recipients Lists
Research Category: P3 Challenge Area - Energy , Pollution Prevention/Sustainable Development , P3 Awards , Sustainability
1. To develop and design an effective multifunctional solar oven that can be mass produced with moderate environmental impact and feasible for distribution to low-income sectors at low cost while using the capital, labor, and materials that are typically available in developing areas of Latin American nations 2. To raise awareness of the environmental and societal impact and issues in this area
A team of seven multidisciplinary engineering students at Rochester Institute of Technology participated in a year long design process that included the following stages:
Stages of the design process:
1) Preliminary trip to Venezuela 2) Recognition and quantification of a need 3) Concept development, preliminary designs and prototypes fabrication (Generation I: three ovens) 4) Engineering analyses and models 5) Redesign iteration and on-site manufacturing (Generation Il-A: two ovens) 6) Field testing in Venezuela 7) Expert input (Dr. Nandwani’s visit) 8) Redesign iteration (Generation Il-B: one oven) and lab testing 9) Final detailed design, performance analysis and cost estimation 10) Impact analysis: economical, environmental and health - Life cycle analysis (LCA)
A preliminary trip was scheduled early in the project to capture the needs (voice of the customer), magnitude of the problem, as well as to initiate contact with local manufacturers and materials suppliers. During December 2004, one of the students along with a faculty mentor visited Caracas and the surrounding areas. During this trip, the RIT group visited a poor neighborhood in the area of Tazón, located about 50 miles SW from Caracas. At this location, with the help of a local catholic church, the group hiked along rural trails to observe cooking practices and converse with the local people. It was found that, the farther into the rural trail people lived, the higher the percentage of the population that cooked with fuelwood. Towards the end of the trail, 100% of the inhabitants use wood to meet their cooking needs. Also, the vast majority showed symptoms of asthma or other respiratory problems. The diet at this location was predominantly rice, beans, and pasta. The local church also provided useful information on some of the cultural barriers, typical family profile (size, etc) and habits of this particular sector. The group also contacted and visited a local wood furniture manufacturer for future construction of solar ovens and to explore the local materials, wages, production capacity, and overall manufacturing practices. Based on the information gathered from the preliminary trip and literature research of papers in the area, a Quality Function Deployment (QFD) matrix was developed. The team utilized this information to help guide the concept development process while paying close attention to the end user needs and design attributes. In order to obtain benchmark performance data, three commercially available ovens were purchased by the team and subjected to product dissection, analysis and the same battery of tests as the in- house developments. The team initially developed ten sketches that were narrowed down to three preliminary designs. These designs were then fabricated in the wood shop at RIT and became known as Generation I.
The models and prototypes from Generation I were subjected to several engineering analyses. The appropriateness of the geometry with respect to the local solar incidence was analyzed using a solar modeling software package (Square One®). This allowed for extraction of the conditions (i.e. incidence angle from azimuth, radiation watts/rn2, etc.) throughout the year, and for a specific location in Venezuela. Additionally, an extensive analysis of the construction material was performed. The physical and mechanical properties of many kinds of wood, wood-composites, plastic, and metals were contrasted for the box materials. The product of this design iteration were two new models (Generation Il-A). In March 2005, two members of the team traveled to Venezuela to get these two ovens manufactured there with local materials and labor, as well as to test them in the field. The testing was performed in Caracas, with one test conducted at an altitude of 1000 meters and the other test at sea level. The purpose was to show feasibility and functionality of the ovens fabricated at location. During the testing, both units reached water pasteurization temperatures (65 °C) and cooking temperatures (82 °C).
As part of the design and development process, the team contacted two of the experts in the field of solar energy cooking. During March, 2005, RIT sponsored and hosted the visit of Dr. Shyam Nandwani who is considered an expert in the field of solar ovens. Additionally, the team exchanged email correspondence another expert in the area. After analyzing the data from the field tests in Venezuela and the expert input, one of the ovens from Generation 11-A was retrofitted to correct and improve some design features. The units were tested in the lab setup for temperature gains and thermal losses, and also outside for actual performance with full solar spectrum. This improved model outperformed Generation lI-A by almost any metric.
After the final design iteration, the Generation III final design was proposed. The final design is large enough to contain two pots and provide enough cooking capacity for a family of 6-8 people, presents double walls filled with shredded recycled paper, cover lid with 3 mm glass separated by 2 cm, heat collector plate, reflectors made with recycled aluminum, as well as reduced height to maximize direct incidence of sunlight. The reflectors were polished to approximate mirror finish. This unit can be fabricated for a total cost of $25.68 ($21.76 materials and $3.92 labor). Although this figure does not include profit, this is about a sixth of the price of the cheapest commercially available oven the team acquired.
The potential impact is quantified as follows. If one thousand ovens are deployed and used throughout the year by families of 6 people each, the following reduction on emission are achieved (in tons/year): CO2 (6,324); CO (318); THC (29.7), NOx (4.49); SO2 (1.10) and PM2.5 (29.3). Assuming cooking energy needs of 680 kg/personlyear, if thousand ovens were continuously used, approximately 4,080,000 kilograms of fuel would be saved every year. Additionally, a complete cradle-to-grave life cycle analysis (LCA) that incorporated the energy, pollution and other implications of manufacturing, distributing, and disposing of these ovens was performed. Sima Pro® version 6.0 software was used in the analysis. Assuming a landfill end-of-life scenario, two ovens were compared in terms of their overall impact to the environment: one of the commercial ovens (SOS sports) versus Generation III. Using the Eco-Indicator 99(H) method for environmental impact, in which a lower score is better, the overall score for the commercial oven was 1.7 points while the Generation III oven scored 0.3 points. This clearly shows a much more benign product and process to the environment. There are additional qualitative benefits of implementing the solar ovens (i.e. health benefits) that are much harder to quantify but nonetheless make a difference in human living standards.
The RIT multidisciplinary Solar Oven team successfully achieved the objectives of designing a low cost oven for developing countries while using materials and processes that are less damaging that the commercial counterparts. In the process, partnerships with local churches and wood furniture manufacturers in Venezuela as well as with expert researchers were developed. All the team members and disciplines greatly contributed to the project. Furthermore, the team members will graduate this spring having been exposed to environmental issues and developed certain sensitivity towards them that, undeniably, most other students do not experience.
Proposed Phase II objectives and strategies:
Phase I in this project provided with the proof-of-concept development. It concluded with a low cost regionally appropriate design for mass production in developing countries, but the awareness objective was achieved only at the team level. However, the fact remains that very few people know about solar ovens and even fewer can afford to have one. Phase II proposes a thorough investigation of the mechanisms and barriers during dissemination at a wider scale with the design developed in Phase I. It would also look into optimizing the design produced by phase I for enhanced performance and minimal cost. The follow up Phase II proposes efforts in two areas: (1) Deployment and dissemination; and (2) Design optimization
Track # 1: Deployment and Dissemination In this track, it is proposed that the final design (Generation III) developed by the team during Phase I, be produced in quantities, delivered to poor areas in a developing country, and its use monitored throughout a summer season. The specific objectives of this track are; (1) Study and quantify the utilization of the technology, rate of adoption, and other statistics on the usage; (2) Document the changes in cooking habits, diet, etc. due to introduction of a new technology; (3) Document the end-of-life practices; (4) Develop the production standards and manufacturing data for a mass production environment; (5) Capture user feedback on existing design features in the oven; and (6) Develop a general understanding of the cultural barriers impeding wider adoption
It is anticipated that a pilot production of approximately 200-250 solar ovens will be manufactured at the local furniture shop that helped with some of the prototype manufacturing in Phase I. A local Company has committed to help in this part of the project. During manufacturing, the industrial engineering techniques of work measurement will be used to develop the production documentation. This includes: work standards, time studies, operations charts, assembly charts, and bill of materials, among others. The next step is then to deploy the ovens at a specific location and instruct the user on their operation. During Phase I, the team established contact with a local church located in a poor rural area. This organization is well embedded in the sector and offered a platform for demonstrations, education, as well as for collecting data from the people in the area. They also have identified and work with key people living in each of the neighborhoods that have, in the past, facilitated and disseminated some of the tasks typical of a religious organization. The facilitators will be instrumental to identify, in turn, those families presenting a profile (family size, responsible family head, able to secure food on a daily basis, etc) suitable for the study. In agreement with the church, the team proposes using both the church facilities and resources (people, building, etc) and the area facilitators for demonstrations, education and general dissemination of the solar oven practices. Educational materials will be developed combining pictorials (for the illiterate) as well as the language of the users (Spanish in this case). An initial trip during the first part of the summer will accomplish fabrication, education and delivery of the ovens. At the end of this trip, approximately 200-250 families will walk away with a solar oven and the necessary instructions for its general use and maintenance.
The user families and their cooking habits will then be monitored at discrete points in time. The team will stay at location for few days after delivery and to provide support to the product and to answer their questions. Two additional trips will be made to the location during the following year and to gather midpoint and final data. Observations and data collection in between these three trips will be left to the church personnel and facilitators. Some of the metrics of interest will include: frequency of use per week, percentage of families still using the ovens, changes in the local diet (success stories and failures), feedback of product features (what they like or dislike, cooking capacity, etc.), reasons for stopping its use, among others. These are to be gathered by means of personal interviews to both the facilitators and the users, observations, and visit to each site where an oven was deployed. Since the ovens will be purposely distributed in high density in some areas (many in neighboring families) and very low density in others, some information on the peer effect, such as help and collaborative use, is expected.
During the final trip, and for those families that stopped using the solar ovens, information on their end-of-life disposal of the product (landfill, some parts recycled, wood burned as combustible, etc) is to be documented. This information will then serve to produce a more accurate Life Cycle Analysis (LCA) for the ovens.
Track # 2: Design Optimization For this track, it is proposed that a different multidisciplinary team of 4-6 undergraduates from Mechanical and Industrial Engineering research into optimizing the design feature and characteristics of the Generation III design. This team will work during the academic year 2005-2006 to perform a series of engineering analyses (thermodynamics, materials, etc) aimed to improve functionality and reduce costs. Some of the design aspects to be optimized include: wall thickress, insulation gap, insulation material and packing density, thickness of collector plate, heat retention, reflectivity rating, window inclination with respect to zenith. All these will be contrasted and compromised with the respective cost curve. A more complete instrumentation setup with additional thermocouples will allow for volumetric heat maps to be developed. This portion should deliver the best performing oven within a certain cost constraints.
The final deliverable of this Phase II will be a technical package that includes: (1) detailed design, performance specs, and manufacturing/distribution plans for a low cost solar oven; (2) the quantified economic, environmental, and health impacts versus number of ovens adopted; and (3) a proven deployment strategy. This package will be then readily available for a government, foundation, non-profit or even profit organization that might be looking for a sound opportunity to make a positive impact upon society and environment. Both the results of this work and the process followed will be presented at the World Conference on Solar Cookers in Granada, Spain during