A Solar Solution: An Analysis of Solar Technology
By Lauren Pardi
Photo by Thomas Owen on Unsplash
Global Warming! Climate Change! Greenhouse Effect! These are phrases everyone hears in the news and in the media that can, and should, frighten us. It is worrisome to think that, according to NASA, 2018 set the record for the hottest year for the fourth year in a row (“2018 Fourth Warmest”). It is also shocking to realize that a study by researchers at Rutgers University has proven that sea levels are rising at the fastest rate in more than 2000 years as glaciers melt due to increased temperatures (Melisurgo). By burning fossil fuels, like coal and oil, humans have created disastrous effects, such as the death of coral reefs, increased forest fires, and the endangerment of many animal species on our planet. When these fossil fuels are burned, they release carbon dioxide into the atmosphere, which depletes the ozone layer that protects the earth from the sun’s harmful rays. The 2018 United Nations Report on global warming states that the only way to prevent the horrors of climate change is through, “draconian cuts in emissions of heat-trapping gases and dramatic changes in the energy field” (U.N. Report). In light of this, sources of energy such as solar power, which is a clean and renewable source, are being reexamined as an alternative, and a possible savior.
The most common method of harnessing the sun’s energy is through photovoltaic panels, otherwise known as solar panels. Many see photovoltaic panels as our best option for gathering solar energy, as it is a viable commercial and large-scale energy source; but as I will illustrate in this paper, these panels also contain a number of flaws, flaws that, I argue, ultimately outweigh their potential benefits. Considering the pitfalls of photovoltaic panels, more resources should be allocated to the development of different solar technology, such as perovskite solar cells, which are equally efficient, but significantly cheaper to produce.
One factor that prevents solar panels from becoming a mainstream source of clean energy is a shortage of resources, which increases the expense of production. The main resource photovoltaic panels rely on is a semiconductor as these panels operate by converting light into electricity through the use of semiconductors. Today’s photovoltaic panels are created using silicon as a semiconductor. Two pieces of silicon are layered with a sheet of metal in between them so that when the photons from sunlight strikes it, the electrons from the top layer of silicon are released and flow to the metal in between the sheets. Then, the multitude of electrons on the surface of the metal flowing creates electricity. The second layer of silicon serves to recollect the electrons so the process can begin again. Therefore, silicon is an integral part of the photovoltaic panel system as it serves as the pathway for the electrons. The issue with silicon is that the price to obtain natural silicon has increased by 30% since 2017, according to a report by the software company GEP Worldwide (“GEP”). This dramatic price increase is due to a higher demand for phones, tablets, and computers that all rely on silicon to build the software chips. Therefore, this has introduced a price barrier to the production of photovoltaic panels due to the cost of the raw materials.
Solar panels also require a significant amount of energy to produce, which causes the price to produce a panel to be higher and negatively impacts the environment. Only pure silicon is a reliable semiconductor; therefore, all silicon mined from the earth must first be treated. Silicon occurs in nature with impurities consisting of a multitude of ridges and gaps in its molecular structure. These gaps allow for different pathways for the electrons to flow on, rather than flowing to the metal which is needed to produce electricity. In short, if the electrons go anywhere else other than the metal, then no electricity will be produced. To prevent this from happening, the silicon must be treated in an electric arc furnace, which produces a temperature of 3272 degrees Fahrenheit. This process yields silicone with 99 percent purity (Solar Cell). The silicon on every single solar panel on the market today, on homes, and in solar farms has withstood this method of extreme heating. Since the silicone in photovoltaic panels must be purified by heating it to extreme temperatures, this dramatically increases the cost of production. The electric arc furnace used to perform this task requires about 400 kilowatts of energy to generate this heat (Solar Cell). For reference, the typical United States home uses 900 kilowatts of electricity every month (Zientara). From this data, one can see the vast amount of energy that is required to produce a solar panel. Further, not only does this energy result in a higher cost of production, but also contributes to the emissions created by burning fossil fuels. In this way photovoltaic panels ultimately worsen the problem of global warming, which results from fossil fuels, that they are attempting to remedy.
Accordingly, these factors have caused solar panels to be expensive for individuals seeking to purchase a clean energy alternative for their homes. An article in Time magazine states, “An average set of rooftop panels costs $20,000 to $30,000 and takes 10 to 15 years to produce enough electricity to pay for itself” (Walsh). These high costs have served as barriers to making solar a widespread use of energy for individuals. Most people are therefore more concerned with choosing the cheaper option to power their homes rather than the renewable alternative of photovoltaic panels. A major hurdle to the spread of solar panels is their existence as a niche market. Since the production of solar panels requires a high energy, this results in the unacceptable cost to the average consumer. While solar panels compose the majority of the means by which solar energy is gathered, they are limited by the expense of production.
Another flaw of photovoltaic panels is that their efficiency is inconsistent, so they do not produce large amounts of power regularly, making them less reliable sources of energy. The solar cell efficiency is determined by the portion of the sun’s energy that can be converted into electricity, through the process of photovoltaics. As of January 2019, EnergySage author Vikram Aggarwal reports the most efficient solar panels have efficiency ratings of only 22%, but the majority have ratings of 15% to 17% (Aggarwal). Another major factor that affects the efficiency of solar panels is susceptibility to damage. In fact, if one part of the solar panel is damaged, even a scratch, then the loss of efficiency is almost as severe as losing the entire panel.
These factors cause solar panels to have low electricity output in comparison to other renewable energy-collecting methods. This can be seen clearly when viewing data collected by the United States Energy Information Administration. According to this data, the following chart shows the United States Energy Consumption for 2017 (see fig. 1).
Figure 1. United States Energy Consumption for 2017
When interpreting this data, the first significant figure to notice is that renewable energy only contributes 11% of the total energy consumed (U.S. Energy Facts). Further, solar power produces only 6% of all renewable energy. Therefore the solar energy gathered from the current solar technology, photovoltaic panels, only accounts for 0.66% of the United States total energy consumption. This infinitesimal contribution is almost embarrassing considering the amount of energy produced by the sun. The sun strikes the earth continuously with enough energy to produce 173,000 terawatts of electricity. Considering the United States alone uses 10 million megawatts of electricity per day, some conversions and math reveal that at any instant, the sun generates enough electricity to power the entire United States for 45 years (“How Much Power”). Further, if we can determine how to make solar power more efficient in harnessing the sun’s rays, then we can greatly diminish the amount of fossil fuels burned to power our planet. This switch to clean energy could minimize our contributions to the harmful effects of climate change.
Besides the high price and inefficiency of solar panels, there are other flaws that restrict them from being successful energy alternatives. In the paper, “Why Not the Sun? Advantages of and Problems with Solar Energy,” Ethan Goffman discusses the drawbacks to photovoltaic panels and promising upcoming solar technology. He claims, “Two major factors have hamstrung the use of photovoltaic cells for generating energy: cost and intermittency” (Goffman). I agree these are major issues with solar panels as I set forth earlier. Yet, Goffman, like many others, fails to highlight some key factors that are further drawbacks to solar panels. One of these factors is land waste from solar farms. In a solar farm, it generally takes 100 square feet to produce one kilowatt of energy. A kilowatt of energy is only enough to power a medium sized air conditioning unit for one hour. So, they do not generate enough power to justify the huge amounts of land being allocated to these farms.
Additionally, Goffman fails to take account of another key pitfall of solar panels. One of the biggest issues with solar panels is that they have a relatively short life span and are difficult to recycle. The typical solar panel has a twenty-year life span, because, as damage occurs over time, their efficiency drops dramatically. Once the photovoltaic panels become too aged to function properly, we encounter another dilemma: how to dispose of the panels. Since solar panels contain impurities such as lead, cadmium and antimony, they cannot be disposed of in regular landfills. While the harmful effects of lead are common knowledge, those of cadmium and antimony are lesser known. Nevertheless, they are much more dangerous as minimal exposure to cadmium can cause osteoporosis, lung diseases, and certain types of cancer. Additionally, antimony can result in the lung disease, pneumoconiosis, and certain cancers as well. There is a fear that these toxic materials could leak into the soil so that rain could carry these chemicals to other areas and contaminate the soil there as well. Accordingly, solar panels are very difficult to recycle properly. As a result, the very tools we wish to use to help turn the tide of climate change will ultimately contribute to its continuance.
In light of the problems with the use of photovoltaic solar panels, I propose more people should turn their attention to developing new solar technologies. Specifically, we should turn to perovskite solar cells as they are based off of the common mineral perovskite instead of silicone. An article by geologist David Bressan, entitled “What are the Most Common Minerals on Earth?” states that perovskite composes 38% of the Earth’s entire volume (Bressan). Along with being an abundant resource, perovskite does not need to be treated at high temperatures like silicon does, because of its inherent crystalline structure. This reduces the cost of production of perovskite solar cells significantly because the producer does not need to pay for the energy required to power an electric arc furnace. Thus, perovskite cells are much cheaper than other solar energy alternatives.
Since perovskite solar cells can be thin, flexible, and even produced in different colors, they can be implemented in many different forms other than the rigid photovoltaic panels we typically associate with solar power today. For example, the panels could be integrated into the body of a car due to their flexibility and because they are thin enough to not increase the weight of the vehicle. Therefore, cars could be produced that do not rely solely on gas, but also on energy from the sun. Additionally, perovskite solar cells can be altered so that they are different colors or even transparent. These more attractive solar cells could be implemented in art, in the architecture of buildings, or perhaps as windows in the future. Considering that perovskite solar cells can be manipulated and altered in so many ways, there are no limits to how this technology could be implemented.
While the implementations of perovskite solar cells are revolutionizing the way we look at solar power, the technology is also competitive with photovoltaic panels in terms of efficiency. These types of solar cells are even being produced by the National Renewable Energy Laboratory, which is where the United States most foremost energy research takes place. According to their findings in the article, “Perovskite Solar Cells,” the cells are already over 20% efficiency rates, making them competitive with solar panels (Perovskite Solar Cells). This is impressive because it took researchers over 60 years to reach over 20% efficiency for traditional solar panels. Considering that these cells are cheaper, thinner, flexible, and customizable, while having the same efficiency as photovoltaic panels, they are an attractive alternative source of solar energy.
Given the benefits of perovskite solar technology, one may wonder why he or she has not seen it on the market yet or even heard of it. The answer is that not enough funds have been allocated to taking these solar cells to the commercial level yet. As an article in The Economist states, “These newfangled cells will have to go up against an incumbent solar-power industry which invested $160 billion in 2017 and is familiar with silicon and how to handle it” (The Economist). This points to one of the key problems with perovskite; almost everyone in the solar power industry is too heavily invested in photovoltaic panels to recognize their worth. Nevertheless, a group from Oxford has taken notice of perovskite and has started a pilot production facility for perovskite solar cells in Germany. Perhaps in the near future we will see these solar cells coming to market in a more significant way.
While the most common type of solar power seen today, photovoltaic panels, are typically viewed as a renewable commercial and large scale energy source, there are numerous downsides to using solar panels -- namely, the expense and inefficiency of the panels as well as the land waste they create and difficulty recycling. All of these issues lead solar panels to being a less clean energy source. Therefore, the problems with photovoltaic panels outweigh their benefits. Accordingly, more money and time should be dedicated to the development of other forms of solar technology, such as perovskite solar cells. Nevertheless, in the upcoming years renewable energy must become a forerunner in the energy consumption ranking so that we can battle the effects of climate change