Definition of Solar Energy
Solar energy is defined as the radiation that comes from the sun and can generate heat bringing about chemical reactions and can even be transformed into electricity. The sun provides earth with solar energy, which is a renewable energy source and also possesses the power to sustain life on earth and provide sustainable energy that is clean for every individual. The amount of solar energy projected by the sun to soil is so much that it is in excess that the earth’s total population cannot manage to use all of it. However, if all energy provided by the sun were to be harnessed suitably, then there is a significant potential that all the energy requirements in the future will be met (Kabir et al., 2018). Currently, solar energy has caught the attention of the world because one, it is a renewable energy source and therefore inexhaustible, and two, because of its non-polluting character, unlike fossil fuels, petroleum, and natural gas.
Because of its intensity and the amount of heat it produces, the sun is by far the most potent energy source, and it also contributes the most considerable amount of energy on earth. However, its intensity at the planet’s surface is low due to the extensive radial spreading by the faraway sun. For it to be used, the solar energy from the sun is converted into electricity first by using solar photovoltaic modules (PT modules). The potential for solar energy is immeasurable; in fact, approximately two hundred thousand times of the world’s electric generating capacity is usually in the form of solar energy (Gong et al., 2019). Regrettably, in as much solar energy itself is free, most of it goes to waste because of the high costs incurred in its collection, conversion and storage. Solar radiation can be converted into two usable forms of energy. That is thermal energy and electrical energy.
Advantages and Disadvantages of Solar Energy
Solar energy is an essential source of energy for planet earth, and as such, when converted into either thermal or electrical energy, it can be very advantageous. One of the advantages of using solar energy is that it is a renewable energy source. The sun will always rise and set, providing solar energy. Solar energy can be collected in all parts of the world daily, and it cannot run out, unlike other forms of energy. Statistics show that the sun will be available for at least five billion years, meaning solar energy is here to stay. Another advantage of solar energy is that it aids in reducing electricity bills. Individuals who have had solar systems installed in their homes and workplaces will be able to meet some, if not all, the electricity bills (Abdulrazzaq & Ali, 2019). How much is saved in terms of electricity bills is also dependent on the size of the solar system that has been installed and the heat and electricity usage.
Thirdly, solar energy is of significance because of its diverse applications. One is its ability to be converted into either heat or electricity. From here, there are numerous ways it can be of use. For example, solar energy can also produce electricity in areas that don’t have access to an energy grid and distil water in regions with insufficient water supply. Solar energy is also used to power satellites in space and can be integrated into materials used for making buildings, for example, solar energy windows. Another advantage of solar energy is its low maintenance costs. Solar systems that have already been set up do not require much maintenance (Al Shehri et al., 2017). As long as they are clean, they are in perfect working condition. In addition, solar panels possess no moving parts, so there is no wear and tear.
Since solar energy is a very reliable energy source, it also has downsides that limit people from using it. The first and most significant disadvantage to solar energy is its high costs. The initial cost of buying a solar system is high because many things have to be considered. That is, the panels, inverters, batteries and the installation cost. The second downside to solar energy is that it is weather dependent. Solar energy relies on the sun, and although solar energy can still be collected on cloudy and rainy days, its efficiency is usually minimal (Aroca-Delgado et al., 2018). Solar panels typically require the sun to collect and convert solar energy effectively. Also, during the nighttime, the efficiency of solar panels reduce. Thirdly, the storage of solar energy is also expensive. Once it has been collected and converted, solar energy has to be used. Otherwise, it has to be stored in large batteries that cost a lot. Lastly, for solar energy to be produced in large amounts, much space needs to be set aside to install solar systems. The solar PV panels take up a lot of space, and at times the panels might not fit the roofs of some buildings.
Solar panels are devices that function to absorb the sun’s rays and then convert them into electricity or heat. A solar panel usually consists of several photovoltaic cells used to produce electricity through the photovoltaic effect. The solar panels have a grid-like pattern on their surface which constitute these cells. Solar panels are very hardy and therefore do not wear and tear quickly. Almost all solar panels in the market are manufactured using crystalline silicon solar cells. As a result, solar panels do not lead to any form of pollution, and they are very effective in combating the harmful emissions of greenhouse gases (Kabir et al., 2018). There are three types of solar panels: monocrystalline, polycrystalline, and thin-film solar panels. The section below discusses every kind of solar panel, how they work, their advantages and disadvantages, and the amount of energy each panel generates.
- Monocrystalline Solar Panels
Monocrystalline solar panels are the oldest type of solar panels in today’s market and the most developed in terms of efficiency. These solar panels are constructed from approximately forty monocrystalline solar cells, and the cells are made from pure silicon (Ahmad et al., 2020). The monocrystalline panels are manufactured in a process known as the Czochralski method, in which silicon is placed in a vat of molten silicon. Monocrystalline panels usually appear black because sunlight interacts with the pure silicon. The back sheets and frames of the panels have a variety of designs and colours. The cells are shaped as squares on the panel with the edges removed. These cells are responsible for trapping the sin’s energy and converting it into heat or electricity. Monocrystalline panels are advantageous because they are space-efficient, have a longer lifespan, and function for more extended periods (Bouaouadja et al., 2020). Monocrystalline solar panels perform better in warm and high heat weather conditions. Some of the disadvantages of this type of solar panel are that they are costly compared to the other classes, and there can be a circuit breakdown when either snow, dirt or shade cover the panel. These solar panels produce energy of up to 546.82 Wh.
Monocrystalline Solar Panel
- Polycrystalline Solar Panels
Polycrystalline solar panels, just like the monocrystalline solar panels, are made from silicon, but what distinguishes the former from the latter is that the polycrystalline cell is made from pieces of the silicon melted together. They are also called multi-crystalline solar panels and are less efficient than monocrystalline solar panels. The silicon fragments are melted, blended in square moulds, and then cool down to form wafers. Polycrystalline panels can be installed in small and large-scale installations (Gong et al., 2019). These solar panels are cheaper, more eco-friendly, and advised to be used in almost any setting. Among the advantages of these solar panels include their cost, which is relatively inexpensive and easier to manufacture. The panels tend to have lower heat tolerance. It makes use of just the right amount of silicon during manufacturing. The disadvantages of the polycrystalline panels included their limited efficiency of around 13-16%. In addition, the silicon used to make these panels have lower purity levels and a less uniform look. The amount of energy generated by this type of solar panel is 517.52 Wh.
Polycrystalline Solar Panel
- Thin-film Solar Panels
This type of solar panel is the newest development of discussions in the market today. Compared to the other two types of solar panels, the most distinguishing feature is that they are not always made from silicon. Some of the materials that can be used to make the thin-film solar panel include amorphous silicon (a-Si), Copper Indium Gallium Selenide (CIGS), and cadmium telluride (CdTe). The manufacturing process consists of placing these primary materials between thin sheets of the conductive material with a glass layer on top for protection. The thin-film solar panels convert solar energy into electrical energy using the photovoltaic effect. Each solar cell on the board constitutes several layers of photon-absorbing materials (Aroca-Delgado et al., 2018). Thin-film solar cells are advantageous because; they have low material consumption, monolithic integration, transparent modules for more straightforward energy conversion, and a shorter energy payback period. However, since they are the newest type of the solar panel in the market, they are less efficient when compared to monocrystalline and polycrystalline solar panels. Another disadvantage is that it requires a lot of space, and due to this, the costs of support structures and cables will also increase—the amount of energy generated by this type of solar panel peaks at 250 W.
Thin-film Solar Panels
The efficiency of Solar Panels in different Temperatures and Climate
Solar panels have different levels of efficiency in different climates and weather. For example, people would assume that solar panels will always work better under high temperatures and when the sun is entirely in hot and cold weather. However, this is not the case. Even though the amount of sun directly hitting the panel contributes significantly to the panel’s power output, the solar panels’ increasing temperature might decrease panel efficiency. When the solar panel is between 150 C and 350 C, it is most efficient, and it is then that it produces maximum power. On cloudy and foggy days, the sunlight is usually obstructed, and the amount of rays hitting the solar panels is decreased significantly, causing the panels to be less efficient. In areas with constant dust storms like the Middle East, the solar panels tend to be covered by dust particles, causing a gradual decrease in the transmission coefficient (Abdulrazzaq & Ali, 2019). This is the amount of light that passes through an optical surface, which is the glass plane of the solar panels. Therefore, the efficiency of solar panels in dusty areas is limited. Rain and Hailstorms usually have a minor effect on the efficiency of solar panels because nowadays, manufacturers have developed solid and waterproof panels.
Maintenance of Solar Panels in Different Climates
Installation of solar systems are a significant investment, and they can provide individuals and organizations with unlimited energy for periods up to twenty-five years and more. In cold climates, solar panels are very efficient, and therefore only a small amount of maintenance practices have to be observed to keep them working. Some of these practices include adjusting the panels at a higher angle to generate maximum energy, and when the panes are covered with snow, it is best to let the snow slide off or hose it so that the snow can melt. In moderate weather conditions, there isn’t a lot of maintenance to be done. Just cleaning the panel a couple of times a year will do the job (Kabir et al., 2018). Finally, it is imperative to maintain the panel’s temperature at 350 C to be highly efficient in scorching conditions. When there is wind and dust, it would be wise to clean the panels to be highly efficient.
Abdulrazzaq, A.A. and Ali, A.H., 2018. Efficiency performances of two MPPT algorithms for PV system with different solar panels irradiances. International Journal of Power Electronics and Drive System (IJPEDS), 9(4), pp.1755-1764.
Ahmad, L., Khordehgah, N., Malinauskaite, J. and Jouhara, H., 2020. Recent advances and applications of solar photovoltaics and thermal technologies. Energy, 207, p.118254.
Al Shehri, A., Parrott, B., Carrasco, P., Al Saiari, H. and Taie, I., 2017. Accelerated testbed for studying the wear, optical and electrical characteristics of dry cleaned PV solar panels. Solar Energy, 146, pp.8-19.
Aroca-Delgado, R., Pérez-Alonso, J., Callejón-Ferre, Á.J. and Velázquez-Martí, B., 2018. Compatibility between crops and solar panels: An overview from shading systems. Sustainability, 10(3), p.743.
Bouaouadja, N., Bouzid, S., Hamidouche, M., Bousbaa, C. and Madjoubi, M., 2020. Effects of sandblasting on the efficiencies of solar panels. Applied Energy, 65(1-4), pp.99-105.
Gong, J., Li, C. and Wasielewski, M.R., 2019. Advances in solar energy conversion. Chemical Society Reviews, 48(7), pp.1862-1864.
Kabir, E., Kumar, P., Kumar, S., Adelodun, A.A. and Kim, K.H., 2018. Solar energy: Potential and future prospects. Renewable and Sustainable Energy Reviews, 82, pp.894-900.