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PBL: Maximizing Use of Sunlight. Group 1: Tham Shi Yuan Wong Yi Ren Benjamin Heng Tan Shao Yuan. Contents. Introduction to problem Product Concepts Cost Effectiveness Problem Faced. Introduction to Problem. The amount of land on earth is only about 148,940,000 km²
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PBL: Maximizing Use of Sunlight Group 1: Tham Shi Yuan Wong Yi Ren Benjamin Heng Tan Shao Yuan
Contents • Introduction to problem • Product • Concepts • Cost Effectiveness • Problem Faced
Introduction to Problem • The amount of land on earth is only about 148,940,000 km² • Some land can’t be used to harness Solar Radiation • E.g. National Monuments, Famous Landmarks • Supply of fossil fuel decreases and demand for electricity increases • It is essential that we maximize the use of the energy direct from the sun.
Product • The product is made of 3 stages: Separating, Focusing, Harnessing • Prism separates the visible and infrared light • Lenses focus the onto the solar panel and food • Solar panel produces electricity to turn skewer for even cooking of food
Concepts – Prism • The prism refracts the components of sunlight • Visible light, infrared light • Due to the different speeds of visible and infrared light, the refract at different angles • Thus, separating these two forms of radiation in sunlight
Concepts - Lenses • The focusing lenses focuses the beams of radiation due to refraction • Visible light and infrared light would be separated after being refracted
Concepts – Solar Panel • Made of p-type and n-type semiconductor
Concepts – Aluminum Foil • Thermal Radiation is reflected off the Aluminum Foil and towards the food • Shiny surfaces are good reflectors of radiation • Food absorbs Thermal Radiation and temperature increases • Food gets cooked =D
The materials involved are cheap and easily available. Solar energy is free Prisms and solar panels cost less than $15 each A cheap motor costs less than $8. Total Cost – about $40 Cost Effectiveness
Cost Effectiveness • Compared to other cookers that run on electricity or charcoal, our product is: • Cheaper • No Fuel needed • Materials less expensive • More time-consuming • Take longer time to reach a certain temperature
Problem Faced • Sun was often covered by clouds, not enough solar power to heat up the item. • Structure of the product to hold prism and lenses difficult to make • Could not be included in our prototype • To calculate the refraction of visible light and infrared light is extremely tedious • So we did not use the prism
Problems Faced • The motor turned rather too quick • Covered part of solar panel with a piece of paper to slow down motor for even cooking of hotdog
However… • The result of our experiment shows that sunlight manipulated in our set-up can: • Power up the motor • Heat the food
However… • We can be sure that the prism can refract infrared light • Since the lenses can be used to focus the heat energy from the sun, means that these infrared rays can be refracted by glass • Note: Visible light does not increase temperature of food significantly.
Acknowledgements • http://www.visitusa.com/california/images/mojave-national-preserve/lavatube-sunlight.jpg • http://en.wikipedia.org/wiki/Earth • http://vle.hci.edu.sg/physics/WebTeach/Optics/Optics_YVONNE/index.htm • http://science.howstuffworks.com/solar-cell.htm • http://www.horizonmeats.ca/images/sausage.jpg