Write a research proposal that presents a hypothesis, designs an effective study based on background research, and argues convincingly for the need for new research. The proposal must include an introduction defining the research issue and hypothesis, a background section summarizing previous studies, a methods section outlining scholarly sources in APA format, and an outcomes section explaining anticipated benefits and the rationale for conducting the research. Use at least five scholarly sources, with at least two incorporating scientific studies, to support your hypothesis and identify research gaps.

The importance of researching and studying renewable energy has never been greater. These forms of energy will outgrow today’s modern technology and will be vital to future generations. However, the transition to more renewable energy is a challenging one, and not creating innovative ways to use renewable energy will slow and delay progress toward a better future. 

Scientists have been working on better applications of renewable energy within several sectors and often encounter obstacles. Most of the time, obstacles are due to a lack of efficiency or too high a capital cost for use. To solve these issues, scientists innovate cost-friendly and more energy-efficient ways to apply renewable energy sources. One of those ways is thermoelectric generators. 

Thermoelectric generators do what the name suggests. They generate electricity by using a difference in heat between two metal plates. The difference in heat between the hot metal and the cold metal causes electrons to move from one side to another, creating a current. This current produces electricity. 

Researchers applied thermoelectric generators to solar cells. In research conducted at the University of Indonesia, researchers learned that solar cells create energy from sunlight, and a lot of the energy is lost as heat (Hakim et al., 2024). Placing thermoelectric generators can increase the efficiency of solar cells by using the lost heat and forming it into additional energy, making the solar cells much more efficient(Hakim et al., 2024). 

To test this theory, researchers had two setups. One was to measure the energy generated in a solar cell without a TEG. They compared it to a PV-TE setup (Photovoltaic-thermoelectric) and measured its energy production. At the end of the study, they found that, overall, the PV-TE setup produced more energy than the stand-alone solar cell. However, when researchers put the TEG directly exposed to the sun and not the PV, the TEG could not produce electricity. This finding was because the water used in the heat sink could not keep its temperature cold enough for a heat difference. Overall, this experiment showed that the application of TEGs could increase the efficiency of clean energy methods. 

However, there are some gaps within the research. For example, the research uses water as the coolant when keeping the cold side cold. Water may not be the best way to keep one side cold to create a heat differential. Also, the type of metal to make that heat differential may not be the best metal to use in a specific appliance. Furthermore, the modules for the TEGs might not be efficient due to size, material, and many other factors. The idea is that we can say that TEGs positively correlate with increasing energy production efficiency. Yet, not much innovation has been done on TEGs that gives the technology a chance to rise and massively influence the world. This research confirms a gap within research that researchers have to address. To further support this claim, I will introduce four other experiments with the same sentiment regarding TEGs.

Evidence

Zeng, H., Yan, Y., Wu, H., Chen, P., Wang, C., Luo, X., Wu, D., & Ding, G. (2024). Bismuth-based ternary chalcogenides pt3bi4x9 (x = S, Se) as promising thermoelectric materials. Journal of Applied Physics, 136(17). https://doi.org/10.1063/5.0230378

Researchers from 3 different universities in China discuss a new type of material called “bismuth-based ternary chalcogenides” and its potential use for producing energy from the thermoelectric phenomenon (Zeng et al., 2024). Specifically, it is a bismuth, platinum, and either sulfur or selenium material. They hypothesize that because this material has low thermal conductivity (doesn’t let heat pass through easily) and a high Seebeck coefficient (a measure of its ability to generate electricity), it can be better used for thermoelectric generators (Zheng et al., 2024). This paper was a theoretical study, meaning they didn’t do a physical experiment but used computer simulations and calculations. These calculations were based on quantum mechanics principles to see if they could perform well in real-world applications. 

In the end, they found that if the material used sulfur, it was effective for n-type conductivity. N-type conductivity means that it was better at using electrons as the main carriers. The selenium was better at p-type conductivity. P-type conductivity uses positive holes as the main carriers of conductivity. So, depending on the usage, both are effective at turning heat into electricity. This finding raises more questions about thermoelectricity that scientists need to investigate further.

Barakat, N., Akkoush, A., El Haj Hassan, F., & Kazan, M. (2024). Ultralow thermal conductivity in Si–ge nanograin mixtures: A cost-effective granular material for thermoelectric applications. Journal of Applied Physics, 136(16). https://doi.org/10.1063/5.0231790

Four researchers associated with multiple universities in Lebanon and one university in France looked at the nanograins of Silicon and Germanium. They hypothesized that nanograin mixtures of silicon and germanium could significantly lower thermal conductivity, making it a better material to generate electricity from heat (Barakat et al.,2024). The idea is that grain size is crucial because smaller grains of a material, as well as rough boundaries, can scatter heat-carrying vibrations, which reduces the flow of heat (Barakat et al.,2024). 

They studied this using advanced computer simulations based on quantum physics to predict the behavior of the materials. They found that smaller grains of Si-Ge had much lower conductivity than traditional Si-Ge alloys, specifically when the grain sizes went to 50 nanometers (Barakat et al.,2024). This finding will be useful for the mass production of thermoelectric appliances, where the materials can have small Si-Ge nanograins to make the thermoelectric effect more efficient. 

Kwon, H., Park, S., Song, W., & Kim, W. (2024). Optimization of thermoelectric systems for maximum power generation based on heat-source and heat-sink conditions. Journal of Applied Physics, 136(15). https://doi.org/10.1063/5.0223204

Most of the time, when talking about TEGs, we talk about optimizing the type of material for the internal temperatures (hot side and cold side), but not enough about the external heat differences and the heat sink. This research focuses on the initial heat source and the heat-sink conditions, simplifying the process and making it more practical for specific real-world applications (Kwon et al.,2024). They tested the idea by making a model that used effective thermal conductivity and thermal resistance to the TEG system. These were designed for marine engines, where the waste heat from the engine exhaust is used to generate power (Kwon et al.,2024). 

In the end, they found that the optimized model for the marine engine increased the TEG system’s power output by a whopping 157% (Kwon et al.,2024). The model concluded that the best performance of the TEG system was achieved when the thermal resistance and the heat exchanger were matched. This approach can significantly improve the efficiency of TEGs later in the future. The finding emphasizes how powerful optimization is when dealing with a technology that hasn’t been innovated yet. 

Anugrah, R. A., & Sugiyanto. (2024). Experimental study using variations of cooling liquids for the utilization of thermoelectric generators applied in a charcoal production furnace. AIP Conference Proceedings, 3220, 090004. https://doi.org/10.1063/5.0228229

Lastly, this study was rather small but had an impact. The idea is that TEGs can convert waste heat into electricity, but their efficiency partially depends on effective cooling. In order to see what cooling was best, researchers from Indonesia tested different coolants to see which one was effective (Anugrah & Sugiyanto,2024). Specifically, they tested water, oil, and a radiator coolant (Anugrah & Sugiyanto,2024). They tested on a charcoal furnace and TEG modules (Anugrah & Sugiyanto,2024). They got the highest heat difference and tested the three different coolants. They found that the radiator coolant-cooled the TEG the best, giving it the highest power output and efficiency (Anugrah & Sugiyanto,2024). This showed that by switching the coolant type, you can get a better electricity yield. This is another example of how modifying the TEG system can yield better results.

In conclusion, there is still a long way to go for TEGs. The biggest comparison I can give is that when humans first made the phone, it did what it was supposed to do. It got in touch with people around your neighborhood. Granted, we couldn’t call anyone around the globe, but we did have some utility. Then, innovation expanded the use of phones to the point where now you can speak to someone who lives across the world. The point is that TEGs are like the beginning of the phone. There are some utilities for it, but it doesn’t offer much. However, the potential of TEGs is something researchers cannot ignore as they can be a cost-effective way to reduce wasted energy, produce more energy, and do it cleanly. That is how powerful TEGs can be, and until we put more research into it, it will stay as potentially important. Thus, the information will give TEGs more thought and research shortly.