Basics of Solar Energy
Information: Definition: Solar or sun energy is derived from the sun and used by people as a source of clean, sustainable, and lasting power. The sun is the brightest star in the galaxy that produces a staggering 173,000 terawatts of solar energy per second. This number is a few times higher than the planet’s whole energy consumption. Solar radiation is the energy diffusion by the sun, which can be converted into electricity or heat. It includes visible and ultraviolet light and infrared radiation. The exact amount of solar radiation on a particular part of the Earth’s surface may vary from time to time due to day/night changes, seasonal alterations, geographical position, etc. Solar technology may differ based on the method of energy conversion, and the two common methods are the usage of photovoltaic cells and mirrors or lenses. Photovoltaic technology applies semiconductor substances such as silicon to directly convert sunlight into electricity. When the sun rays hit the PV cell surface, the electrons are freed and can be used for electricity. Concentrating solar-thermal power uses mirrors or lenses to concentrate sunlight on a small area and produce heat that can later be converted into electricity. The transformation process used here includes the steam engine principle: most of the modern CSP facilities use steam as power for the turbine. Main Ideas:- Definition and nature of solar radiation.
- Solar technologies and the division into photovoltaic and concentrating methods.
- Description of the two methods.
- The use of solar energy is currently promoted in the majority of industrialized countries around the world as the most promising source of power.
Every technology has its advantages and may be used in different conditions. PV systems may be used in different conditions and are much more versatile – they may be installed both on the roofs of houses in the city and in remote areas. CSP should be used for the generation of big amounts of energy, and do it without the sun in particular, as they have thermal energy storage systems. How Do They Evolve the Sun’s Power? The primary purpose of solar panels is the conversion of sunlight into electricity. Solar panels are also recognizable as photovoltaic (PV) systems. In the process of functioning, these panels absorb photons in sunlight. These particles excite the electrons from the semiconductor substance located in the panel, and the result is produced – the creation of an electric current. The effect of conversion is called the photovoltaic effect. Solar panels are usually incorporated of multiple cells, and these groups of cells are named the solar modules. Many such modules combined together form the solar power system or plant. The rate of conversion of sunlight into electricity depends on the material of the cell. It may reach from 15% to 20% for commercially-produced panels, though there are models with 22% efficiency and higher. Solar Cells Solar cells serve as the primary components of solar panels. They typically include silicon, which is a perfect semiconductor with abundant availability. The solar cell consists of two sides, a positive part, and a negative part, which are also called p-type and n-type, respectively. As sunlight kisses the cell, it excites free electrons in silicon and creates energy that results in current flow, which is then transmitted through various appliances as power. Moreover, a solar cell can also be perceived as a plate with two end contacts, as the current flow is also collected by two metallic contacts. The efficiency of a particular solar cell is a measure of conversion of sunlight into electrical power and ranges between 15 and 20%, which is the percentage of available commercial silicon cells. The process of sunlight conversion into electricity via the solar cell may comprise several steps:
- Absorption: The photon from the sunlight is absorbed by solar panels, and its energy excites free electrons in the semiconductor material of the solar cell.
- Generation of Electric Current: The stimulated electrons create an electric current in the cell, which is then made for collection.
- Collection: The electric current in the cell is collected by means of metallic contacts that are attached to the top and bottom of the solar cell.
- Conversion: Current that is generated in solar cells can be stored in batteries or converted through an inverter, which turns direct current into alternating current electricity for the appliances in homes and businesses.
- Utilization: The produced electricity can either be used for powering certain devices in accommodation or fed into grids for cities and towns.
The process of solar cell operation is seen as the simplest and most efficient way of sustainable energy use, as it transforms sunlight into electrical power with the help of manufactured devices. Solar power provides a minimal environmental impact compared to the entire energy life cycle path such as coal and natural gases. Solar power or the utilization of energy emitted by the sun in the form of solar radiations is highly viable and environmentally friendly. The cause of its minimal impact is the less emission of greenhouse gases in the cycle of production and consumption of solar energy. The effect cause less pollution to the air and reduces the entire carbon footprint of energy generation. The utilization of solar power reduces water usage in power institutions since solar power systems do not require water for its run. Therefore, it saves on water which is a scarce resource and save the environment from pollution caused by the energy sector when they release hot water to the environment. However, prospective users of solar power should be aware that the manufacturing of the solar systems is not entirely environmentally friendly and the disposal of the solar panels cause some cost to the environment. Additionally, solar panels usage pose some risks to the environment since they contain hazardous materials and other toxic substances. Although this may seem a major cause of concern for the environment; there are minimal effects when compared to other causes of energy for example fossil fuels. Solar power is also a renewable energy source and the sun does not generate any costs for its consumption. Carbon Footprint and Recyclability The carbon footprint of solar power isn’t really significant in comparison to other forms of energy. Although there are emissions associated with the production, transportation, and installation of solar panels, they are offset but the clean nature of the energy the panels produce. Solar panels have a life span of about 25 years, with the potential of being operational even longer. Furthermore, the decrease of the solar panel price per unit brings more and more opportunities for various recycling systems associated with the technology. At the moment, most components of most solar panels, such as glass, aluminum, and silicon, are recyclable, but the recycling practice is complex and costs quite a lot of money. Thanks to the research and development connected to the process, the recyclability rate of the product will function on a more efficient and cost-effective level, decreasing the initial carbon footprint of the product even lower. Integration of Solar Energy into Electricity Grids The integration of solar energy into electricity grids is one of the most important process in the creation of a more viable and sustainable energy system. Solar energy integration into electricity grids take a few different steps. The process starts with the connection of the solar power installation, both the large solar plants in unused parts of the world or dense cities as well as smaller residential systems, to the already existing electricity grid of the area. This ensures that the produced energy is allocated to the locations that need them, without the need to keep transporting the sun power between more and more distant places. The process also needs more advanced electricity grid technology. Smart grid systems have to be equipped in order to manage the variable nature of the sun power and the consistency of the electrical stream. Energy storage products also function hand-in-hand with the solar energy and the electricity grid, such as the various batteries used by consumers. Literally, the term of grid decarbonisation refers to the decrease or almost full absence of carbon emissions associated with the operation of a grid. In this case, we are talking about electricity generation, and therefore decarbonisation could mean the complete absence of any fossil fuels used for this purpose. Here is where the sun’s invaluable contribution comes into play. Solar energy is the main protagonist and enabler of decarbonisation. The sun is an eternal and most powerful source of heat and light, and its radiation makes it possible to generate electricity which features nothing but minimal waste products. Technological advancement in the sphere of solar energy systems also contributes to a more successful implementation of decarbonisation by creating economic and operational benefits. Implementing solar grids could create multiplier effects in combination with other sources of renewable energy, for instance wind or hydro. These relatively clean energy sources together will contribute to the decarbonisation of the grid and make energy production more versatile. A solar farm’s component parts include panels, inverters to convert DC into AC, transformers to increase the voltage, and monitoring systems. As solar technology grows and its costs decrease, decarbonisation will become increasingly feasible. This fact is realized by the governments of many countries and utility companies and precipitates investment into solar energy and its inclusion in country-wise energy policies. Proofreading Generating solar power in variable conditions is a challenge faced by solar energy systems. Indeed, whilst it is possible to generate electricity by solar panels on cloudy days and in other weather conditions, their efficiency is greatly reduced. The most common way of tackling this problem is to incorporate a storage solution into the solar energy system. Generally, this solution is a battery. When solar panels generate more electricity than a building supported by this system needs, as in a sunny day with no one present in a building, this extra energy is used to charge the battery. When solar panels cannot generate enough electricity, the power to the building is supplied from the battery. A battery of a solar power system can store enough energy to last a couple of days, which means that it can support the building on a cloudy day when no sun can be seen. Moreover, there are also two other technologies to enhance the usability of solar panels in various conditions. The first technology is using bifacial solar panels. Those are designed to catch sunlight on both sides. The second technology is having tracking systems. Generally, this system allows moving the solar panels’ angle, allowing them to catch the Sun at its best. Solar generation is heavily impacted by a diverse range of geographic factors that affect the amount of sunlight a location receives throughout the year. The most comprehensive of these factors is the location’s latitude, since the earth is a sphere and the presence of more or less sunlight depends on the angle at which it hits the surface. Accordingly, locations near the equator are generally more suitable for solar generation, since the sun shines directly on them as opposed to more advanced angles for other locations. The second consideration is the amount of sunlight a location receives annually, which is attached to the average levels of sunshine. Other aspects, such as the shape of the terrain and its elevation, also play a significant role. For example, areas with higher altitudes are generally sunnier, while frequent shading from mountains or buildings devalues the potential of solar generation.
