Currently there is an energy crisis in the world today that stems from the continued use of fossil fuels, increasing population, and in the United States an aversion to the use of nuclear power. In addition the infrastructure to support the necessary power usage is not available in many locations. These issues are part of what LPC is attempting to combat through the use of a renewable and alternative energy solutions.
The Thermoelectric Generator Phase 1 has a number of basic design requirements set forth by the predetermined product design specifications. Of these specifications, there are a number of statements that supersede others to the point of being a design requirement. A phase change material must be used as a means to hold energy for the TEG Phase 1 as the team’s mentor specifically requested such a product. In addition, a Fresnel lens was also requested as a key component of the design. The current goal for the product is to be able to charge a cell phone through the latent heat transfer of the phase change material after the Sun goes down. Finally, the final product needs to be standalone and portable in order to fully achieve the team’s marketing goals. These basic design requirements make up the highest priorities among the various product design specifications.
Latent Power Corporation belongs to the renewable energy industry aimed at low maintenance solid-state thermoelectric generators. Specifically, their product is geared toward the outdoor enthusiast who wishes to go off-grid and power a small device. The competitors that LPC faces are those that are in the portable thermoelectric generator market.
LPC has completed specific steps in preparation for entering this industry. To begin, thorough research was conducted on thermoelectric generators that are currently on the market. The need for reliable off-grid energy guided LPC’s commitment to create a phase change thermoelectric generator that will maintain the ability to operate at night. The team also committed to using renewable solar energy as the power source to remain competitive within their expected price range. The team identified the renewable energy source and nighttime function as entry points into the thermoelectric generator market. LPC also analyzed competitor strategies. SWOT analysis on major competitors was performed to help LPC develop their marketing strategies and design specifications. A professional logo was also developed to appeal to the expected customer base.
The main competition that Team 6A will encounter is BioLite, Inc. and Power Practical. Both companies sell off-grid products that use fire to generate electricity. BioLite’s flagship product is focused more on the wood burning device attached to a thermoelectric generator, while Power Practical’s main product derives its power from being placed on a wood burning device. Both flagship products transform heat into power. Both products are marketed towards outdoor enthusiasts and both companies have a range of products supplemental to their flagship devices. Power Practical can be found in almost every US retail camping and outdoor venue and their products can be found on Amazon’s Website. Biolite can be found on major retail outdoor websites as well as Amazon. These products are available almost everywhere domestically and both companies are currently working to implement their devices in developing regions such as Uganda and sub-Saharan Africa. Overall, LPC’s market research and competitor analysis has prepared them to enter the thermoelectric generator market as a strong competitor.
Proof of Concept
TEG Phase 1 will be a portable thermoelectric generator utilizing both paraffin as a phase change material and copper rods for greater thermal conductivity. The housing will be made of acrylic and will measure less than two feet by two feet by two feet in volume. Atop the device will be a multiple-array Fresnel lens. Inside the housing, there will be a metal box that will hold the PCM as well as the copper rods. The metal box will be painted with black thermoelectric paint. Directly below the metal box will be four thermoelectric modules. Copper fins will also be included below the thermoelectric modules to help dissipate heat for the cold junction. An electrical outlet will be wired to the thermoelectric modules to power a user device. Finally, the device will sit atop a tripod to provide stability.
The market for a renewable energy device such as the TEG Phase 1 is currently wide open. There are some competitors, but none utilize Latent Power Corporation’s specific proof of concept. They use fire or only solar energy as their fuel, not phase change materials in combination with solar. TEG Phase 1 is a device intended toward the pleasure camper and is a unique concept that could ultimately help many live off-grid. Although the initial device is small, the concept could grow into yielding large results by combining solar, PCM’s, and thermoelectric generators. TEG Phase 1 is a first generation product whose concepts could help reduce society’s dependence on fossil fuels. Although the small scale TEG Phase 1 device may not drastically affect fossil fuel consumption, the concepts have a great potential to do so.
Final Design Description
The TEG Phase 1 is a thermoelectric generator designed to have handles and a tripod to make for ease of use and set up. It will be aesthetically pleasing with a sleek construction of clear acrylic allowing users to see the inner workings of the product. The thick acrylic walls also increase the durability of the product. The generator will be small enough that is will not be a bulky new addition to anyone’s camping equipment supplies. It will be a lightweight construction at less than 30 pounds. The TEG Phase 1 will also be available to the public at an economical value of less than $150. This generator will feature an electrical outlet that will include a USB connection accompanied with a cover. LPC’s generator will deliver power for 30 minutes after the sun sets outperforming most other solar powered generators. The thermoelectric generator will function for the majority of the year making it viable for use in any season.
Characteristics of the Project
The TEG Phase 1 is a solar powered electricity generator that is able to store heat with the use of a phase change material. This heat storage allows the project to provide power past sundown. This is able to occur because when the phase change material solidifies, it gives off heat to provide additional energy to the product. A Fresnel lens is used to focus the sunlight to better heat up the phase change material container. The TEG Phase 1 is built with acrylic walls, and connected to a tripod. The product has vents which help cool the bottom side of the thermoelectric modules. This cooling effect is amplified with the use of fins. The rectangular design allows for easy storage while making it simple to manufacture. The project is designed to be used outside in sunny conditions. A traditional outlet/USB combo is part of the project. The outlet is designed to be used to charge small portable devices.
Project’s Purpose and Consumer Use
Currently on the market, there is a shortage of products that cater specifically to a consumer who is both an outdoorsman and the environmentalist who wishes to live off-grid. Additionally, there is not a product on the market that utilizes a combination of the sun and paraffin to power a device. Nor is there a product that has the capability to run on a 24 hour basis. TEG Phase 1 fulfills those needs. The product appeals to the outdoorsman in that it is portable yet rugged. TEG Phase 1 also draws the environmentalist with its off-grid capabilities as well as its self-sustaining qualities. For instance, the device won’t have to be recharged with batteries, one can simply place it in the sun. Unlike traditional solar panels that can only charge in the sun, TEG Phase 1 has the ability to work at night as well, as the device releases heat when it cools, which is then converted to power.
The TEG Phase 1 will have several components contained within a clear acrylic structure that is mounted onto a stabilizing tripod. The first phase of the assembly process will be to assemble the phase change material (PCM) container. It will be filled with the paraffin wax and then properly sealed. The PCM lid must be fully assembled before connecting to the base. This requires the copper rods be coated with the gasket maker and then screwed through the lid. The seam around the lid requires a coating of the silicon gasket maker as well. After the sealant has set, the thermoelectric modules can be attached to the base of the PCM container with thermally conductive glue. This allows for the fin attachments and electrical connections to be completed next. The container will also be fully insulated by attaching foam insulation to the exterior of the box using fireproof sealant and glue. In addition to the insulation, the top of the PCM container will be painted with solar collecting paint to enhance the performance of the prototype.
After the PCM box assembly is complete, the exterior housing can be constructed around it. This is accomplished using acrylic cement to chemically bond the exterior acrylic panels together. The acrylic panels will be glued with the PCM box and electrical components in their predetermined positions. Therefore, the PCM box will be slid into position between the panels prior to gluing. The last two assemblies include the connection of the tripod to the base of the acrylic and the placement of the Fresnel lens on the apex of the entire assembly along with its supports. Once the fabrication is complete, LPC will begin testing the TEG Phase 1 prototype.
Testing and Results
Testing and Results
Latent Power Corp. (L.P.C.) implemented multiple stages of testing to ensure the success of the TEG Phase 1 prototype. Overall, the product functioned as intended, however the magnitude of power output was lower than expected. Despite the minimal output, the TEG Phase 1 still successfully generated power using the lens and phase change material assembly. The knowledge gathered from the prototype testing will be extremely useful in developing a more powerful product to combat the renewable energy demand. Latent Power Corp. provides an easy, sustainable, and inexpensive way for users to generate energy in remote locations. During testing, LPC noticed extreme interest from nearby viewers that were attracted to the TEG Phase 1’s sleek and appealing design. The TEG Phase 1 achieved many of the desired outcomes throughout the testing process.
Testing Phase 1: TEM Circuit Verification
In order to for TEG Phase 1 to be successful, the thermoelectric modules had to be correctly wired together in accordance with the product schematic. During fabrication, Team 6 shortened the wires from the modules and used the scrap wire to complete the circuitry. It was decided that in order to maximize both amperage and voltage, three sets of modules were connected in series and then collectively wired in parallel. When soldering the modules together, Team 6 tested the wiring using the continuity function on the multimeter to ensure that the connection was complete. All of the connections were a success except for one. Unfortunately, it was difficult to readily spot the break, so the group had to pull apart and re-solder two connections. After the two connections were re-soldered, the wiring passed the continuity function on the multimeter.
The thermoelectric modules were then soldered to the switch/outlet subassembly. Again, the connection was tested using the continuity tester function and the results for that procedure are discussed in the Testing Phase 3 section. Figure 1 and 2 highlight the TEM circuit verification testing.
Testing Phase 2: Lens Verification
The second phase of testing investigated the functionality of the Fresnel lens/acrylic subassembly, seen in Fig. 3. The subassembly was taken outside in order to verify its function in direct sunlight. The test was performed to examine the optimal orientation and operating limitations of the lens in the product’s final working environment. To perform the test, the height and angle of the lens was changed in reference to the ground. The lens focal lengths were focused onto a piece of test wood at 1 pm to ensure that the sun was in an optimal position above the lens. Visual inspection was used to verify the success of each test trial. The success of each trial was subjective and based on the intensity of the lens focal points. The major purpose of this test was to confirm the functionality of the lens, confirm the focal length of the subassembly, and gauge if the lens functioned as intended. The group used the information gathered from this test to ensure that no modifications were needed before permanently attaching the subassembly to the prototype body. Table 1 summarizes the lens verification/visual inspection results.
Table 1: Phase 2 lens verification results.
|Lens Visual Inspection Test Results|
|Lens Height [cm]||Angle [degrees]||Results/Notes|
|1.64||0||Burned Test Piece|
|1.65||0||Optimal – Burned Test Piece|
|1.66||0||Lightly Burned Test Piece|
|1.64||5||Asymmetrical Focal Points|
|1.65||5||Asymmetrical Focal Points|
|1.66||5||Asymmetrical Focal Points|
The results confirmed that the lens performed as intended at the correct focal length of 1.65 cm and the optimal orientation parallel to the sun. The information gathered from this testing phase confirmed the need for orientation control in the final prototype, which is provided by the tripod.
Testing Phase 3: Final Product Circuit Verification
The circuit was designed using the thermoelectric modules, power switch, and outlet assembly. The modules were placed into simple circuit containing three banks of modules placed in series and then wired into parallel. During each connection the circuit was tested to ensure that the circuit had no disconnect and that the soldering was effectively connected. This was again performed using the continuity function on a multimeter. This was applied to the addition of the switch used within the same circuit as well.
Testing Phase 4: Final Product Testing
The construction of the TEG Phase 1 was completed with the connection of the device to the accompanying tripod. Once the fabrication process was complete, the device could be fully tested. To do this LPC set up the TEG Phase 1 in a location where no buildings or foliage would obscure the sunlight shining onto the Fresnel lens. However, there was inclement weather during this testing phase providing suboptimal conditions and lower voltages than expected. Table 2 summarizes the testing data and shows that the voltage was recorded at an average interval of five minutes.
Table 2: Final product testing data. This table shows that after the phase change material reached a certain temperature the voltage steadied out.
(hour of day)
|Time Charging [mins]||Voltage
By inspection, it can be seen where the device begins to heat up and stabilizes. The instances of cloud cover can be seen as well. This is especially clear from 11:40 to 11:45. The device also shows continued power production after it was moved inside at 12:45. The output is drastically reduced as a result.
The TEG Phase 1 performed the tasks it was designed to complete. However, these tasks were not performed to the level of expectation. It was expected that the device would produce a greater amount of voltage. It is expected that it would meet these expectations with optimal outdoor weather conditions and if higher performance modules were purchased.
Meet the Team
Mirica Krajewski has lived in Reno, Nevada for the past several years and is a senior Mechanical Engineering student at the University of Nevada, Reno. She intends to graduate in May, 2018. Her hard work is reflected in her GPA of 3.585. In her studies, the main engineering skill that she has learned was knowing that every project has trial and error (iteration). Mirica also learned that some projects fail, and that is where the greatest learning occurs. One of the most difficult assignments that she and a group of three other students were tasked with was building an NXT Lego Mindstorm robot to navigate a difficult course in her Introduction to Mechanical Engineering class. Mirica came up with the idea to use a color sensor to detect colors on the card and relate it to the robot’s movement. For instance, if the sensor read the color blue, the robot moved forward and if it read green, it moved backwards. If the sensor read white, it stopped. With Mirica’s design, her group was able to earn full points for the assignment. Outside of school, her greatest accomplishment are her two children, aged ten and seven. For the past four semesters, Mirica was working as an undergraduate teaching assistant for Engineering Communications. Mirica is currently working as an engineering intern at Jensen Water Resources. After graduation, she plans on working for Jensen Water Resources as a project manager.
Rebecca Histed, originally from Southern California, transferred to UNR in 2015 to complete her degree in Mechanical Engineering. While attending UNR, she has maintained a 3.92 GPA and plans to graduate in the spring of 2018. Rebecca has been a dynamics teaching assistant for multiple semesters and is currently working in the Engineering Tutoring Center on campus. Rebecca also has experience as a project engineer intern for The Whiting-Turner Contracting Company. She worked on the MEP project management team overseeing geothermal design and installation. After graduation, Rebecca plans on getting a job in industry and returning to school for a master’s degree. In her spare time, Rebecca enjoys skiing, snowboarding, and spending time with her husband and dog.
Ean Edwards has strived to produce exceptional results at all times and puts his all into every task that befalls him. The most challenging project Ean has been involved in stem from his internship where he helps design HVAC and plumbing systems. He was placed in charge the design process and tasked with first learning how to complete this process on his own and having it adhere to the established codes and standards while under a time limit. This design project was most challenging because it forced him to find different ways to learn and adapt to changing circumstances in a competitive industry. Ean has improved and developed several engineering skills during his stint in a collegiate curriculum. These skills include improving his personal iterative design process, interpersonal skills, and project management skills. These skills all lend to a more effective engineer. Ean has been involved in a few different projects outside of school. He has volunteered to be an “Engineering Expert” at a local elementary school for a trebuchet competition. Here he had to take a design created by the students and ensure that it worked. This took a great deal of analytical skill to determine why the range was so low and improve upon it without changing the students design drastically. He had to determine ways to shift the center of gravity so that the device no longer overturned itself during the throw.
Ean Edwards hails from Las Vegas, Nevada and moved to Reno to continue his education. His current goals include attempting to learn a programming language during the winter break and continuing to learn more HVAC and plumbing design. Closely followed by improving his project management skills.
Neil Mehta was born in San Francisco, California but mostly grew up in Reno, Nevada. Initially a Nevada high school graduate, Neil transferred to UNR after a number of years at the University of California – Berkeley. Neil’s most challenging engineering project was during his time at Berkeley. This project involved designing a contraption which would transport a tennis ball, golf ball, and a ping pong ball a specified distance away over the course of three trials. This contraption needed to only have a single start input to begin its task. Throughout the design of this transporter, Neil was able to come up with a innovative solution to launch the various balls one at a time through the use of cheap household materials. Outside of school or work, Neil Mehta earned his second degree black belt during high school. Throughout his engineering career, Neil has developed his hand calculation problem solving skills the most. After graduation, Neil plans on moving to California to better support his Dad. In addition, Neil plans to establish himself as an engineer within the competitive Northern California industry.
Adan Leon is originally from Reno, Nevada but attended university in San Diego before changing his major and transferring to UNR in 2015. Adan has consistently made the dean’s list and has always had a job during his time in school. Adan’s most challenging engineering project was when he lead a project to reconstruct the engine of a mini cooper over the course of six months shortly after his return to Reno. During his academic career Adan has greatly improved his communication, time management, critical thinking, and programming skills. Adan is proud of a project he completed where he rebuilt a vintage road bicycle last year and painted it with Nevada colors. Adan intends to join the Navy after graduation and pursue more education after serving in the military.