Chapter TwoThe Review of Related Literature The Sun is the most ubiquitous form of energy on the planet, sustaining all life on Earth.  Furthermore, the Sun is one of the most readily available forms of energy, and is the brightest and the most familiar object in the sky.  Life on Earth would not be possible without it (Stern, 2004).  While this is the case, ironically, solar power remains widely untouched and untapped for the generation of renewable energy.  While the usage of solar power is increasing, solar energy provides five-tenths of 1 percent of the total energy consumed in the United States, and harbors the most minimal energy generated from common renewable sources (DOE/NREL ENTECH, 2016).  A common goal among solar power researchers is to make solar power energy cheap and efficient to use.  Copper tubing and photovoltaic semiconductors are exemplary materials for solar power electricity generation and heating, as solar power is trapped in the system and can considerably heat water that is passed through the system under solar energy.  In order to achieve max efficiency, we must manipulate the water flow rate to  remove superfluous energy in the solar harvesting system in a cost-effective manner.History of Solar Power Harvesting solar power is not a recent adaptation.  Harvesting solar power began in 1876 when selenium, a photovoltaic semiconductor, produced electricity when exposed to light.  From that point, technological advances in solar power have made solar power a staple name in renewable energy sources.  The use of copper in solar power generation, however, is a moderately new innovation.  In 1904, Wilhelm Hallwachs used a copper and cuprous oxide synthesis, and ascertained that the material obtained photosensitivity (U.S. Department of Energy, 2006).  The incentive of using specifically copper, however, as a major component of solar power, is an exceptionally notable tool, known to efficiently harvest solar power.  Incorporation of Photovoltaics     Another increasing popular adaptation of solar power harvesting is photovoltaics.  Photovoltaics refers to the conversion of light to electricity atomically.  Certain materials attain a property referred to as the photoelectric effect, which causes the material to generate electricity as the material absorbs light (Knier, 2008).  This effect was first documented in 1839 by physicist Edmond Becquerel, sequenced by Albert Einstein who described the photoelectric effect and subsequently, was awarded a Nobel prize in physics for his work.  Solar cells (photovoltaic cells) use semiconductors materials that can include germanium or selenium.  Bell Laboratories built the first photovoltaic structure.  However, because of the substantial cost of the material, photovoltaics failed to gain extensive usage for many years  (U.S. Department of Energy, 2006).Incorporation of Copper to harvest Solar Power    Copper is a pervasive material found in many electrical systems and circuits.   Copper is also vital to providing power to solar photovoltaic systems, wind turbines, energy storage, and electric automotives (Strong, 2017).  Attaining a very high conductivity and durability, copper significantly increases the efficiency of solar power cells.  Furthermore, the introduction of copper also increases performance of these systems and is cost-effective.  However, copper’s dominance in electrical generation fails to stop there.  Copper remains an important photovoltaic component and is sustainable, recyclable, and retains its main properties after many uses (Strong, 2017).  The incorporation of copper into the electrical circuit has been a substantial adaptation, working its way in almost every circuit we work with, across the expanse of modern technology.  The incorporation of the photovoltaic has also been vital to the growth of solar power in this new world of technology.  The assimilation of these materials help synthesize new circuits that run using renewable energy sources.Making The System     The copper coil, solar powered water heater.  This system consists of a series of coils of copper circumvented in a container, accessible to the Sun.  Copper is twice the conductivity of competing materials such as aluminum, improving efficiency and bypassing problems such as slow heating and partial conductivity (Blue Clean, 2014).   Furthermore, the coils prevent any breakages in the circuit, so there is no need for any high-end costly warrantied materials.  As the water flows through the circuit, it naturally circulates.  The copper coil absorbs energy through the surface, causing the solar infrared rays to increase the temperature located in the coil.  In addition, the insulated material retains the heat effectively.  (Solar Direct, 2017).  Requiring a local water supply and the Sun, the system pumps water through the system, sustaining very high temperatures without the need for electricity or gas.  (Duan, 2010)New Advances in Solar PowerA significant area of solar power usage is the home.  A problem that has arised from solar power enthusiasts is the idiosyncratic appearance of the solar panels on the roofs of homes.  Therefore, advances have been made to construct a “Solar skin,” which blends in the house exterior creating  a flush appearance (Richardson, 2017).  In addition, Sistine Solar and MIT has created a product that allows solar panels to configure to a roof without fluctuating the capability and production of the system (Martindale, 2017).  This adaptation plans to increase solar power usage in the United States and promote a more proficient method to harvest the clean energy.  Solar power innovation does not stop there, solar cells have also undergone a major innovational upgrade.  Solar cells, which produce electricity under the photoelectric effect, have always been plagued with minmal efficiency rates, however, new studies show advances in solar cell technology.  The average solar cell is approximately 15% efficient, where about 85% of the sunlight that comes in contact with the cells remains unconverted (Davison, n.d.) Researchers at Imperial College University, made use of gallium arsenide, which they theorize could make solar cell systems attain threefold efficiency.  These cells are named “triple junction cells,” and their exceptionally high efficiency is due to the chemically adapted function that specializes in the capture and retention of the Sun’s energy.  Researchers at Ohio State University have also made groundbreaking achievements in solar cell efficiency.  Producing a solar cell 20% efficient and 25% cheaper than what is available on the current market, their secret to this innovation is placing a rechargeable battery incorporated into the solar system, rather than making use of distinct systems.  This system not only improves efficiency, but also lowers costs by allowing these components to function in synthesis and cost significantly less.  These common beliefs are ubiquitous in the solar power discussion of harvesting the Sun efficiently. ApplicationThese innovations also yield advances and solve intrinsic problems in the copper coil system.  By incorporating the advances in solar cells and photovoltaics into the copper coil system, heating could not be the only goal of the coil system.  Other applications of the solar cell include harvesting electrical supply from solar power using the copper coil, creating a magnetic circuit, and incorporating the coil more into common technology.  In addition, substituting copper for other materials such as silicon could pose benefits such as low toxicity and high cell efficiencies (Blakers et al., 2013).Solar power remains the fastest growing source of new energy in the world.  Renewable energy’s share of electricity generation is expected to raise to 30% from 24% in 2022 (Vaughan, 2017).   As more cities claim dependence of solar harvesting, the incorporation of a cheap and effective solar power source is growing ever more important.  Advancing the copper coil may seem rudimentary, but research shows copper arising with semiconductors as key materials which will be prioritized as the world moves toward clean energy.SummaryMany scientific studies explain the importance of solar power in the new age of technology.  Greenhouse gas emissions consistently become more dangerous as temperatures fluctuate, negatively affecting precious ecosystems around the world.  Furthermore, it now becomes apparent that these nonrenewable sources of energy are now being replaced with green energy.  The tactical improvements of solar power over the years have shown promise to change the way the Sun is used and viewed among us. Integrating the copper coil into households, would save money and reduces emissions immensely.  Advancing the efficiency of this coil by optimizing the flow rate of water and testing the photovoltaic system, will prove to increase the amount of energy we gain from the Sun.  Consolidating new materials such as gallium arsenide or perovskite, may prove to elevate this simple system into technology for the future.