Let's talk about the Advantages and Disadvantages of Solar Energy , Which represents a very attractive alternative to the use of fossil fuels because it has the particularity of being a clean, silent, and renewable energy. However, it still has many limitations such as the low efficiency and the low power generated worldwide.
The use of solar energy is as old as human history. However the development of solar panels started in 1839 when Becquerel Discovered the photovoltaic effect for the first time.
Later in 1877, the photovoltaic effect on solid selenium was observed by Adams and Day. It was until 1883, when Fritz developed the first photovoltaic cell with an efficiency that was less than 1% (Singh, 2013).
Today, solar panels are used in a wide range of applications, from residential rooftop power generation to medium-scale power generation in solar plants (Jacobson and Delucchi, 2011).
However, among the various types of renewable energy resources, solar energy is the least used, as it only supplies about 0.1% of the world's energy consumption, which corresponds to 0.00001% of available solar radiation (Chen, 2011).
The sun is the most abundant energy resource available to human society. The fact is that if only 50% of New Mexico's solar light were transformed into usable energy, it could satisfy all the energy needs of the United States.
As a result of intense research and development, the use of solar energy, especially the development of solar panels, is enjoying a surprisingly rapid progress. Therefore, it is reasonable to expect solar energy to become the main source of energy in the second half of the 21st century, surpassing all fossil fuel energy resources (Chen, 2011).
1- Clean energy
The main attraction of solar panel systems (photovoltaic panels) is that they produce electrical energy without damaging the environment, directly transforming a free and inexhaustible energy source like solar energy into electricity.
The various forms of solar energy are solar heat, photovoltaic solar energy and solar thermal energy; These offer an energy resource respectful to the climate and very abundant for the humanity (Singh, 2013).
In addition, solar energy has the potential to play a very important role in reducing greenhouse gas emissions, as approximately two-thirds of the CO2 emissions from fossil fuels are associated with generation, heating and transport Of electricity.
If these activities were replaced by solar energy, very low CO2 emissions would occur (MIT, 2005). Solar panels generate CO2 only in the process of their production, once installed they no longer pollute, in addition, the production of energy is silent and does not emit hazardous waste.
2- Renewable energy
As the global supply of fossil fuels declines, there is a strong need for clean and affordable renewable energy sources to meet the increasing demands for energy.
Sunlight is the largest source of energy available. It provides the Earth with more energy in 1 hour than it consumes on the planet in a whole year (Barlev et al, 2011). For this reason, photovoltaic solar energy can and should play an important role within a sustainable energy system of the future.
Solar energy, along with wind power, are the renewable activities that have grown the most in recent years.
Solar energy systems are characterized by their autonomy, do not require extensive wiring, since it is possible to move the installation wherever energy is required.
For example, we could directly install enough solar panels in our home, and we would no longer need the urban power grid to get our electricity.
For this reason, photovoltaic solar energy is one of the key technologies for generating decentralized electricity for homes around the world, and along with some other renewable energy systems are an excellent choice in remote areas to produce low or medium power levels ,
4- It requires little maintenance and has long life
Another advantage is that solar panels require very little maintenance to operate, since once installed can spend long periods of time operating without supervision; From time to time it will be necessary to clean the panels so that the accumulated dust does not impede the passage of light.
In addition, the life of the panels is very high, which, despite its cost, is worth the investment in this technology.
5- It is modular
Because solar energy is modular, we can have it for personal use. It is possible to start with the installation of a solar panel and increase the energy capacity with the passage of time.
This way the system of solar panels can be so big or small according to the requirements of each person. The photovoltaic system can vary widely in size and application, from wristwatches or calculators to remote buildings or spacecraft
The types of solar modules are polycrystalline, monocrystalline, thin layer and solar carpet, each type of module being characterized by differences in the shape of its cells.
The efficiency of a photovoltaic module depends on the amount of solar charge and the area covered by the panel, the greater the area covered by the solar panel, the more energy will be generated.
6- Variety of applications
The use of solar energy is generally divided into two main areas that are thermal and solar. The former uses the sun as a direct source of thermal energy and is most commonly used to supply hot water to homes and swimming pools.
The solar energy system seeks to convert sunlight directly into electricity through a process known as photovoltaic. It can be used for solar vehicle applications and solar systems for domestic electric power use (Singh, 2013).
7- Increasingly accessible
The technologies associated with solar energy systems are not yet fully established, so the price of a unit of energy generated from a photovoltaic system is greater than the cost of conventional energy supplied to urban areas.
However, costs for solar energy are currently falling and markets are expanding to facilitate greater energy production and more technological advances. In addition, costs are expected to continue to decline (Singh, 2013).
The supply of electricity to areas farthest from cities is becoming cheaper with photovoltaic solar energy, as it is simpler with falling prices for photovoltaic systems. All of this implies a promising role for solar energy systems in the near future.
8- Technological improvements
Recent and ongoing improvements in solar thermal generation technologies, coupled with the need for more renewable energy sources, have increased interest in concentrating solar thermal energy. An advantage is that it can store the heat and make the energy half-available.
Concentrated solar systems use reflective mirrors or lenses to focus sunlight on a fluid to warm it to a high temperature.
The heated fluid flows from the manifold to a heat engine in which part of the heat is converted into electricity. Some types of concentrated solar energy allow heat to be stored for many hours so that electricity can be produced at night (Jacobson and Delucchi, 2011).
Stored thermal energy can allow electricity generation to extend to periods without solar resources and to provide backup energy during periods with reduced sunlight that can be caused by cloud cover.
The storage medium is typically a molten salt, which has extremely high storage efficiencies in demonstration systems. (Sioshansi and Denholm, 2010).
9- Low efficiency
Most photovoltaic cells on the market are made with silicon and can be mainly monocrystalline or polycrystalline. The former are cells made from very thin sheets cut from a single crystal of silicon.
Polycrystalline cells are cells made from a block of silicon crystals. The efficiency of both types of cells is maintained between 12% and 17% (Hernández et al, 2015). This means that most of the solar energy is wasted.
The efficiency of solar energy depends mainly on the photovoltaic panels that are the ones that generate electricity.
However, all elements of the solar system contribute to its efficiency, the energy is converted from the sun through the photovoltaic array, the regulators, the battery, the wiring and the inverter to supply the AC load. In general, lower quality systems have a lower efficiency (Singh, 2013).
The climatic conditions also influence the efficiency, which depends on the level of solar irradiation and temperature. For example, a cloud passing over a portion of solar cells or over a submodule will reduce the output power of the solar panels. Under certain cloud conditions, the changes can be dramatic and rapid (Singh, 2013).
10- Intermittent power
The main factor limiting the use of solar energy is the state of time. During night or on very cloudy days there would be no energy or very little.
In addition, this variation in energy production generally does not match the demand pattern at the same time scales (Delucchi and Jacobson 2011).
For this reason, the solar system requires a storage system to be able to supply energy in the absence of the sun (Singh, 2013)
11- Not enough
The ability to generate energy from solar panels is very low compared to the current energy use. Solar energy accounts for only 1% of global electricity production and, together with other renewable energies on the planet, barely reaches 2% of global energy production. All the world's solar plans produce the same energy as that generated by 2 coal plants.
12- It is not the same different regions
The intensity of energy that can be generated by solar panels varies according to the different regions of the planet, which is why a large-scale solar plant project would be much more viable in certain regions where solar irradiation is high (Figure 1 ).
However, it also depends on the resources and policy of each country. Currently Germany is the country with the most solar energy capacity, with 38.2 GW, closely following China, Japan, the United States and Italy. (Beiter, 2015).
Figure 1. Solar radiation in the world (Chen, 2011).
13- Environmental impact
Large-scale solar power plants are developing at a rapid pace, and are being set up to use thousands or millions of hectares of land. In quantitative terms, large-scale solar power plants occupy almost the same area per kWh as the life cycles of coal power plants. (Turney and Fthenakis, 2011).
The elimination of forests to create space for solar energy causes significant CO2 emissions, around 36 g of CO2 per kWh-1, however these emissions are low, compared to the CO2 emissions of coal-based electricity that Are approximately 1100 g of CO2 per kWh-1. (Turney and Fthenakis, 2011).
Large-scale solar plant construction can have an impact on wildlife. Solar projects in the desert of the Southwest United States have generated controversy due to concerns about habitat and ecosystem alteration, so large areas of desert land in California may be excluded from the development of solar states United States (Turney and Fthenakis 2011).
- Barlev, D., Vidu, R., & Stroeve, P. (2011). Innovation in concentrated solar power. Solar Energy Materials and Solar Cells, 95 (10), 2703-2725.
- Beiter, P., Brown, A., Heimiller, D., Davidson, C., Denholm, P., Melius, J., & Porro, G. (2015). 1. 2014 Renewable Energy Data Book.
- Chen, C. Julian. (2011). Physics of solar energy. ISBN 978-0-470-64780-6
- Delucchi, M.A., & Jacobson, M. Z. (2011). Providing all global energy with wind, water, and solar power, Part II: Reliability, system and transmission costs, and policies. Energy policy, 39 (3), 1170-1190.
- Hernández, J. M., Alonso, B. D. C., Nochebuena, M.C.V., & Oliver, J.S. (2015). Integration of photovoltaic solar energy systems in the ZAE office building in Germany. Sustainable Habitat, 2 (2), 59-72.
- Jacobson, M. Z., & Delucchi, M.A. (2011). Providing all global energy with wind, water, and solar power, Part I: Technologies, energy resources, quantities and areas of infrastructure, and materials. Energy Policy, 39 (3), 1154-1169.
- MIT. Massachusetts Institute of Technology, (2005) The Feature of Solar Energy, an Interdisciplinary Mit Study. ISBN (978-0-928008-9-8). P. 356
- Singh, G.K. (2013). Solar power generation by PV (photovoltaic) technology: a review. Energy, 53, 1-13.
- Sioshansi, R., & Denholm, P. (2010). The value of concentrating solar power and thermal energy storage. IEEE Transactions on Sustainable Energy, 1 (3), 173-183.
- Turney, D., & Fthenakis, V. (2011). Environmental impacts from the installation and operation of large-scale solar power plants. Renewable and Sustainable Energy Reviews, 15 (6), 3261-3270.