Grantee Research Project Results
Final Report: Design of a Small – Scale Solar Chimney for Sustainable Power
EPA Grant Number: SU833917Title: Design of a Small – Scale Solar Chimney for Sustainable Power
Investigators: Tebbe, Patrick , Moaveni, Saeed
Institution: Minnesota State University - Mankato
EPA Project Officer: Page, Angela
Phase: I
Project Period: August 21, 2008 through April 30, 2009
Project Amount: $10,000
RFA: P3 Awards: A National Student Design Competition for Sustainability Focusing on People, Prosperity and the Planet (2008) RFA Text | Recipients Lists
Research Category: Pollution Prevention/Sustainable Development , P3 Challenge Area - Air Quality , P3 Awards , Sustainable and Healthy Communities
Objective:
Access to energy sources is a major limitation in many areas of the world. This is particularly true for developing economies which have limited resources to devote to traditional power generation. This project proposed to design and test a small-scale solar chimney for use as a renewable energy source. Traditionally designed for large-scale power production, the project examined various manufacturing and component alternatives to produce a smaller, cheaper, version of a solar chimney which can be employed for low power applications with potential for large quality of life impacts. The technical challenge can be described as creating a balance between manufacturing method, power output, cost, and application of the generated power. The engineering design focused on use of cheap readily available materials and locally feasible manufacturing methods. The project related to People by providing a modest but very useful power source which could supply power to low wattage lights, charge electronics such as cell phones, and with continued refinement power refrigerators for preserving medicines and vaccines. The project addressed Prosperity by seeking to minimize the initial cost through better design while creating a system with little to no long term cost (i.e. the power source is free and maintenance is minimal). The design addressed the Planet by making use of a renewable source of energy (the sun), using existing unused space, and having a minimal impact on the local environment. Collaborations were developed between the local students and students in Ghana. Evaluation of local feasibility in Ghana will be facilitated by input from the Ghana students and faculty advisor in Ghana. Design of the solar chimney was undertaken as the student’s undergraduate senior projects.
Proposed Phase II Objectives and Strategies:
The second phase of development for the small scale solar chimney involves four key objectives; 1) gathering additional performance and design data from chimneys to be built in the target regions (i.e. Ghana and Botswana), 2) refine the overall chimney design, particularly with regard to the turbine and generator, 3) produce a design guide and training materials suitable for distribution, and 4) construct a demonstration chimney using local resources in a village of Ghana.
Summary/Accomplishments (Outputs/Outcomes):
After several months of design and testing it has been determined that a small scale solar chimney can be built using nearly any local materials and simple hand tools without needing superior construction knowledge. The biggest obstacle to over come was the weather conditions. The Minnesota climate, especially during winter is quite harsh, with temperatures dipping into the negative 20 degrees Fahrenheit range with winds up to 60 mph, thus creating the need to build the structure of the solar chimney out of heavy duty materials so it can withstand snow, ice, rain, and high winds. In a developing country such as Ghana, these conditions are not applicable, winds only in the 10 mph range and temperatures between 70 and 100 degrees Fahrenheit. Thus in different climates the solar chimney structure will vary depending on the conditions it must endure.
After multiple collector designs it has been determined that the collector should be composed of a panelized structure. Depending on the climate the panels should range between 4’ x 4’ all the way up to a 10’ x 10’ panel. The paneled design has several benefits; including ease of construction and assembly, collector area can easily be increased or decreased depending on conditions and damaged panels can easily be repaired individually without endangering the rest of the collector.
Conclusions:
From the design testing and data collection an average temperature gradient between the ambient temperature and collector temperature of 22 degrees Fahrenheit was obtained. When velocity readings were taken with a velocity meter, the average wind velocity through the chimney was around 2 m/s. From this temperature gradient and velocity readings in February, it was calculated that the theoretical power output would be around 1.8W.
With a larger collector area and greater temperature difference it would be possible to obtain a decent amount of produced power from this green energy source.
Supplemental Keywords:
energy, renewable energy, solar energy, sustainable environment, alternative energy;The perspectives, information and conclusions conveyed in research project abstracts, progress reports, final reports, journal abstracts and journal publications convey the viewpoints of the principal investigator and may not represent the views and policies of ORD and EPA. Conclusions drawn by the principal investigators have not been reviewed by the Agency.