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h4. Concentrated Cooker Team
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h6. Members: Emma Lejeune and Meghan Hilbert
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This semester the concentrated cooker sub-team will look into methods for focusing more light into the cookers than the cooker glazing intercepts on its own.   We are especially interested in using [fresnel lenses|SolarCooker:Fresenl Lens and non-imaging optics articles.].


Our objective is to optimize the capability and efficiency of existing solar ovens, specifically by harnessing even more sunlight than the solar ovens can inherently absorb. Solar cookers are designed to utilize primarily direct sunlight; however, in this group, we strive to find ways of using lenses and reflectors to redirect that which wouldn't normally reach the cooker.  Ideally, we want to be able to use the lenses to access more sunlight overall so it can be more efficient and reach higher temperatures. In accordance with our target community's local culture, reaching frying temperatures could be a significant breakthrough, as it would allow for staples such as tortillas to be prepared. Since glass lenses are cumbersome and brittle, as well as expensive, this group will be looking into a more durable, more easily manufactured, and cheaper lens--the Fresnel lens. 

TraditionalIn methodsour ofsecond concentratingyear lighton withthe FresnelESW lensesSolar involve only concentrating light to a single point. With this method, temperatures high enough to melt metals are attainable. However, as stated above, our goal is to Ovens Team, we will continue our work with the already existing solar ovens in order to enhance their performance. Concentrating light to a single point alone would not achieve this goal. Due to the limited research on using Fresnel lenses without solely concentrating light to a single point (or line), we will need to do preliminary research to understand the properties of the lenses before creating a design to use them to supplementFresnel lenses. Three semesters of research and experimentation with the lenses have allowed us to become comfortable with how they work and with what applications we can pursue.

Traveling to Nicaragua last spring and working with Las Mujeres Solares gave us a new awareness of the limitations of the solar ovens., Ouras researchwell willas focusa chieflygreater onunderstanding theirof abilitythe toculture redirect light and concentratedaily lightpractices toof the areaspeople in rightSabana afterGrande. andThese rightinsights beforehave theshed focallight pointon ofhow the lenses lens.  

Our first set of tests will be conducted using lasers, as the lens' behavior is dependent on the presence of parallel beams of light. After understanding the basic mechanism for concentrating and redirecting light using the lenses, we will come up with a working design to supplement the solar ovens. Depending on the properties of the lenses, our design might incorporate reflectors to take full advantage of their properties. Currently, we plan on using the reflective material available in the lab to design reflectors.

Pending the results of our preliminary testing, our end goal is to use the lenses and reflectors to reach higher temperatures inside the ovens, ideally high enough to fry food. In addition, we need to consider the cost, the accessibility and the practicality of daily use of the lenses. We aim to refine design practices until these goals are met.   
can be applied in more pragmatic and relevant ways. This semester, our main goal is to build on our work from last semester in using the lenses to cook tortillas. In addition, we plan to travel to Nicaragua this spring where we hope to communicate our ideas about using Fresnel lenses to the Solar Women.

Because we are both graduating at the end of this semester, we plan to create a detailed record of the work we have done so far. Leaving behind this record will help future students to pick up where we left off and continue the work with Fresnel lenses.


   

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h6. For More Information:\\

* [Final Report Fall 2012|^Fall 2012 Solar Ovens Lens Final Report.docx]
* [Final Report Spring 2012|^Fresnel Lens Final Report Spring 2012.doc]
* [Final Report Spring 2011|^Concentrated Cooker Final Report.doc]
* [Fresnel Lenses and Non-imaging Optics Articles|SolarCooker:Fresenl Lens and non-imaging optics articles.]
* [Final Report Fall Lenses 2012|^Lenses Final Report Fall 2011 1-20-12.pdf]