What Is Solar Energy? Pros and Cons. Why should you go Solar?

Solar Energy in Nepal

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What Is Solar Energy? Pros and Cons. Why should you go Solar?

Admin 7th February 2021

Solar energy is the light and heat that appears from the sun and turns into electricity and heat energy. Well, solar power is a sustainable and endless source of energy. The presence of this energy is remarkably high which can’t be replaced constantly. It aces on every aspect either environmentally, economically, or socially.  Equally important, this energy merits on net metering. It is the manner of crediting homeowners for the electricity they generate and repay to the power grid. 


Even so, solar power energy captured for less than an hour can be in use for an entire year but without a storage device, this energy can’t work at night. A storage device such as batteries and inverter is required. Though solar technologies are considerably expensive, the service provided aftermath aids in saving electricity bills with enormous electrical and heat production for all dates. Nevertheless, Solar energies have the fewest negative influence on the environment than any other energy source.


What Is Solar Energy? 


The utmost choice for seeking to transform into green energy is Solar Power energy. It is the energy that comes from the sun which can be switched into thermal or electrical energy. Harmoniously, the sun will be shining for the forthcoming billion of years as the fairest source. So this energy will be available for the rest of our lives. This will probably help with harnessing a variety of applications such as generating electricity, providing heat inside the house, and heating water.


According to a recent survey, it is studied that roughly 173,000 terawatts of this energy come upon the surface of Earth. Those equivalents are more than 10,000 times the total need for energy in the world. Along with that, every particle of sun rays that encompasses Earth carries a power that fuels our planets. Solar Power energy is the ultimate source that can be relied on by every weather system and other energy sources of Earth. Shortly, the energy can be stored even in cloudy or rainy weather but the power would be relatively lower than on sunny days. 


Solar Photovoltaic and Solar Thermal Installed Capacity

Source: International Renewable Energy Agency (IREA)


In 2017, the International Energy Agency noted that solar has become the Fastest Growing source of power in the world. The Solar generation is predicted to be uplifted from 11% of total renewable production in 2017 to 48% by 2050. Besides, 58% of people who have solar panels installed remarks as the cleanest source of energy which doesn’t contribute to climate change. And 59% of people mention about their electricity bills being minimized. As per BBC Future Now, China is the leading country in the aspects of this energy having around 130 gigawatts capacity.


Apart from that, the solar radiation that hits the surface of the Earth every hour could be enough for almost a whole year. This happens because inside the sun’s core there is a nuclear fusion reaction. It assembles the numerous energy known as photons, that radiates the outer surface of the sun in the form of light and heat. Also, this energy is a fundamental solution in battling the climate crisis and overcoming the dependency on fossil fuels. 


Above all, Solar energy is a renewable source of energy. The harnessing power from the sun is indefatigable. The installation process is a struggle but later after the construction is counted as the majorly availing source. Not only that, the energy prevents from the habitats being destroyed. Normally forests are demolished for excavating raw materials like fuels. When a tree is cut, it releases the carbon dioxide stored in it. It brings climate change. At the same time according to WWF, 8 out of 10 animals live on the ground. They will lose their habitats. Switching to this energy will help to keep the environment tidy and keep these territories intact for the animals. 


Types of Solar Energy


Being the best alternative in generating electricity, heating, or desalinating water, Solar Power energy technologies can be classified in two possible ways.


Solar Photovoltaic Panels Electricity Generation

Source: Green Match


  • Photovoltaics (PV)


A PV is an electronic device that converts sunlight to electricity directly. The other name for photovoltaics is solar cells. It helps in powering any smaller electronic devices such as calculators, parking meters, water pumps. Well, PV was discovered in 1839 by a 19-year French Physicist Alexander Edmond Becquerel. He found this invention when Becquerel poured silver chloride into an acidic solution and exposed it to sunlight. This resulted in platinum electrodes attaching to it and producing an electric current.  


Moreover, in 1954 the Bell Telephone Laboratories in the United States introduced the first solar PV module that can produce a usable amount of electricity. The PV links with solar panels: a collection of dozens or hundreds of solar cells that are held with the silicon-based semiconductor. The semiconductor absorbs sunlight, then the electrons get loosen. The electric fields, positive on one side and negative on another side, lead the loose electrons to produce an electric current in one direction. 


When light energy hits the solar cell, electrons are tapped loose from the atoms in the semiconductor material. If electrical conductors are attached to both positive and negative sides that form an electrical circuit. The electrons can be caught in the form of an electric current. Some of the light spectra are reflected, some are too weak to create electricity and some create heat energy instead of electricity. That is electricity, later can be used to power a load.


Solar Energy in Bulb

Source: NASA 


The building-integrated PVs are usually the outer part of the structure, including it generates electricity for onsite use or export grid. This option can help in lessening the cost of electricity and reducing pollution. However, High temperatures can decrease the output of solar systems, and clouds and rainfall can affect system output and maintenance requirements. Thus, this requires regular cleaning due to the tremendous level of air pollution. 


The design of a Building-Integrated PV system should take into account whether the building will be able to work entirely independent of the electrical grid, which requires batteries and other on-site energy storage systems. The silicon panels have higher electricity outputs per square meter, but greater costs and design restrictions. Thin-film materials generate less electricity per square meter, but are less expensive and perhaps integrated more easily onto more surfaces.


Furthermore, The Photovoltaic effect is taken as presumably the most common way to harness this energy today. It is widely used in spacecraft too. The International Space Station has 2 solar array wings that are about 33,000 each solar cell. Each cell obtains electricity through PVs that allow astronauts to operate with no scarcity. Despite that, Photovoltaic power stations have been built all over the world. Its technology can be fitted on a smaller scale either on roofs or walls of the building to form electricity. 


Besides that, the cost of manufacturing solar panels is exceedingly affordable out of which it makes the cheapest form of electricity. Even solar panels come in a variety of shades depending on the type of material need while constructing. And it has a lifespan of almost 30 years.


  • Solar Thermal Energy 


Solar thermal energy plants specialize in creating solar heaters for the indoor heating system and heating water. It collects heat from solar radiation directly to use the heating systems. While compared to Photovoltaics, solar thermal energy has a wider range of uses. This is affordable because the Return on Investment is 3-6 years short. Also, most people use this energy due to its inexpensiveness.


There are three types of solar thermal energy. Such as low temperatures can be utilized for heating the house, medium heat for swimming pools and high temperatures help in producing electricity for everyday operation in homes and offices. 


  • Low temperature solar thermal energy systems:


The low temperature solar thermal energy system necessitates climate control for heating and cooling the air. For cooling, the sun rays are blocked in the needed area whereas for heating the rays are allowed into space. It’s similar to Passive solar heating practice. This doesn’t require any mechanical equipment or fuels to warm the living areas. 


  • Medium temperature solar thermal energy systems:


The mid temperature thermal energy cover on heating of the water. Solar water heating is an alternative to a traditional water heating system. It includes gas or electric water heaters, tankless twine water heaters, or water pump heaters. The usage of the energy comes from the sun and is a worthy utilization to heat water. The heat captured in the collectors on the rooftop will be fetched to the water running through the pipelines. This is a direct process that doesn’t require water heaters powered with oil or gas.


  • High temperature solar thermal energy systems:


This is the replica of Concentrated solar power. It is generally used for producing electricity in a higher range. The mirrors are induced so that the focused sun rays can collect the heat energy generously. The sunrays are focused on the tubes holding fluid. Later the warmed liquid is used to transform water into steam. That will turn a turbine and assist in generating electricity. 


  • Concentrated Solar Power (CSP)


Well, Concentrated Solar Power was initially developed in the 1980s. The CSP uses the mirror to reflect and concentrate solar rays onto the receiver and transform them into heat. The energy concentrated in the CSP plant can be stored and used to produce electricity when needed by spinning the turbine or powering an engine. This system can be used to upgrade the value and dispatchable power by combining the concentrated power plants in hybrid power plants. Also, it can be integrated into existing power plants that use coal, natural gases, biofuel, or geothermal plants. In addition to that, CSP can use fossil fuels to supplement the solar amounts when the solar radiation is low. 

Concentrated Solar Power (CSP)

Source: Context Solar


At the same time, the primary challenge for energy generation is project financing. As the areas of high solar radiation might not be available in every location. A CSP plant operates most efficiently when built according to 100 MW size or higher. Although a typical CSP requires 5 to 10 acres of land per MW of capacity, the varying technology can bring a hitch. Apart from that, the plant must be sited on the land suitable for power generation with adequate access to high voltage transmission infrastructures. Because the transmission lines are the key for the development of utility-scale solar power projects to move electricity from solar plants to end-users.


Similarly, there are four types of Concentrated Solar Power Technologies:


Concentrated Solar Power Technology

Source: Science Direct


  • Parabolic Trough Systems:


In Parabolic Trough Systems, the sun’s energy is centered in curved mirrors onto a receiver tube that runs down the center of a trough. The temperature of heat transfer fluid flowing from the receiver tube, usual thermal oil, is increased from 750º F or higher.  Then it passes through a heat exchanger to heat water and produce steam. The steam manages a traditional steam turbine power system to generate electricity. 


A typical solar collector field contains hundreds of parallel rows of troughs connected as a series of loops that are located on the north-south axis. It is because troughs can easily trace the sun from east to west. Thus, the individual collector modules are typically about 20 feet tall and almost 450 feet long.


  • Central Receiver Systems:


Central Receiver or Power Tower systems use heliostats, that is sun-tracking mirrors, to focus the energy of the sunlight onto a receiver at the tower's topmost part. This allows higher operating temperature and greater efficiencies. A heat transfer fluid heated in the receiver up to about 1111º F is used to generate steam. In return, it can be used in a conventional turbine generator to produce electricity. 


The power towers make use of steam as the heat transfer fluid in the past. But that does not confer itself to storage. Khi Solar One of South Africa and Ivanpah in California is operated by heating water to steam directly. But Gemasolar (2011), Crescent Dunes (2013), and Noor III (2018) use molten salts because of their higher heat transfer and energy storage capabilities.


  • Linear Fresnel Systems:


This replicates the concept of Curved Mirror or Parabolic Trough systems, but with the long parallel rows of low costing flat mirrors. These are aligned in a north-south inclination to maximize annual and summer energy collection. The mirrors are laid flat on the ground and reflectors focus the sun’s energy onto the elevated receivers that consist of a system of tubes through which water flows. Like the Parabolic and Tower Power system, Linear Fresnel System can incorporate storage in a power block. The concentrated sunlight absorbs the supreme heat that can boil the water. In that way, the system can generate steam for direct use in industrial steam applications. 


  • Parabolic Dish Systems:


A Parabolic Dish System holds parabolic shaped point focus concentrators in the form of a dish. It reflects the solar radiation onto a receiver scaled at the prime focal point. These concentrators are scaled on a structure where two-axis tracking systems follow the sun. Unlike other CSP technologies that engage steam to create electricity through turbines, the Parabolic Dish System uses a working fluid such as hydrogen that is heated up to 1200º F in the receiver to drive an engine. The dish can attain extremely high temperatures. It can hold for use in solar reactors for making solar fuels that require the highest temperatures. 


How is Solar Energy generated?


Firstly, the photons that are radiated from the sun to earth must be captured. The radiations are collected in the arrays of photovoltaics. Then it will be converted into a usable layout that is electricity. An inverter will turn the electricity from the PV array. And lastly, it will be transferred to an electronic grid or directly to the home to make it work simultaneously. 


Well, the photovoltaic arrays are the set of PV cells. They are connected to supply enough necessary energy that a single cell can produce. It is made up of special silicon which has a both positive and a negative side. This specialty helps in transmitting electricity successfully. Though PV arrays produce larger energy, the cell is affixed to several other cells using metal connectors to produce a single electrical output. 


Inventors play a vital role in transforming the limitations of PV arrays. The solar power energy produced by the Photovoltaics array is direct current (DC) electricity. The DC is inappropriate for every electronic device. So the inverter revises the amount and categorizes the electrical power supplied by the system. It converts DC into AC so that every other electronic device can use it thoroughly. Also, make sure the voltage level provided by the system is constant. 


To maximize methodically, a solar tracker and array checker should be used. The solar tracker will go after sensing the spot of the sun by light sensors and the checkers will pass the PV arrays based on the result from the solar tracker. Finally, the solar power energy generating system can be used when the PV array has been converted into a functioning form. Afterward, the power can be delivered directly to every type of electrical equipment.


Types of Solar Panel 


Types of Solar Panel

Source: EnergySage


  • Thin-film PV:


This is the faster growing yet smaller part of the profitable solar market. Such firms involve more in developing experimental technologies that state this option as less efficient but cheaper. But, this requires a larger space, labor, and materials for producing the same amount of energy. The most commonly used thin-film cells are made of amorphous silicon. However, new types of thin-film photovoltaics are being introduced in the market at present time. Some of them include copper indium diselenide, cadmium telluride, and gallium arsenide.


  • Crystalline Silicon Technology


Crystalline silicon technology is the most efficient form of solar photovoltaics. Crystalline silicon technologies make up about 85% of the photovoltaic market. There are two usual types of crystalline silicon photovoltaics: monocrystalline and Polycrystalline, both of which are wafer-based. 

Crystalline Silicon Technology

Source: EnergySage


  • Monocrystalline semiconductor:


The monocrystalline semiconductor wafers are cut from single-crystal silicon metals. It is generally discerned with black cells because of the reaction of the light with the pure silicon crystal. However, the solar panel has variant colors behind it. The performance of this panel is highly efficient and costly too.


  • Multi-crystalline or Polycrystalline semiconductor:


These semiconductor wafers are grown in thin sheets or are cut from directionally solidified blocks. These are bluish because of the light reflecting on the silicon particles in the cell. The reflection is different than in a monocrystalline silicon wafer. The semiconductor can be installed at a lower price whereas the performance capability is also less efficient. 


Fun Facts about Sun


  • About a million Earths can befit inside the Sun

  • The mass of the sun is approximately 330,000 greater than Earth

  • Sun is the mixture of every color

  • Composed with 70% of hydrogen and 28% of Helium

  • The shape is a Perfect Sphere

  • Sun Travels at a speed of 220 km per second

  • It takes 8 minutes to reach the sunlight on Earth

  • Distance between the sun and earth is never the same

  • Sun has a powerful magnetic field

  • Classified as a Yellow Dwarf Star


Uses of Solar Energy


Solar Power energy is a supple energy technology. It can either be built as a distributed generation that is located nearby the point of use or utility-scale solar power plants. These methods can assist in storing the energy they produce for distribution after the sunsets. As this energy is used to transform for either Thermal Energy and Electrical Energy. The uses of both energies go hand in hand. 


Specifically,  thermal energy is taken as one of the most sustainable and renewable energies of the earth. It is collected in two ways, one of two is passive solar heating that refers to controlling the thermal energy by storing free heat energy in the cold months, and deflecting it in the warm months. And the other one is active solar heating which means it uses this energy to heat a fluid. Then transfer the solar heat directly to the interior space or a storage system for later use. The uses of Solar Power Energy are:


  • Solar Water Heater


Solar water heaters use a rooftop cell to ingest heat and transfer it to the water tank. The use of solar power energy elongates the water heating systems. One of the prominent utilization is heating swimming pools. Water is firstly circulated to a collector. Well, it is heated by sunlight and later pumped back into the pool. With costs between $3,000 and $4,000 and a payback of 1.5 to 7 years, the U.S. Department of Energy says that “solar pool heating is the most cost-effective use of this energy in many climates.”


Well, two replicates have taken place that are Active Water Heating systems and Passive Water Heating systems. 


The Active Water Heating systems make proper utilization of mechanical circulating pumps that rotates water or other fluids from rooftop heat collecting panels. Then into a water stored tank. Likewise, Passive hot water systems work on an opposite strategy. It doesn’t require mechanical pumps. Normally, the collector is installed lower than the storage tank. This operates by the simple physics of heat naturally rising. But it takes serious effort on installing as the heavy tanks reside above the roof. 


  • Solar Lighting


The Solar Lights are omnipresent everywhere. The security lights, road signs, street lights, and now even home landscaping are some of the examples. The solar panels charge the batteries during the day. The charge is often enough to keep the lights turned on for the whole night. Commonly, solar lightning technologies can be easily accessible lately. There are seasonal lighting displays for holidays too.  And with the use of solar panels, other systems are available that can power multiple landscape lights. 


  • Solar House Heating


The energy of the sun can benefit from heating the house. This could sound expensive and complex, but it has been in a simple practice. Solar panels lined with polycrystalline silicon are linked together on a roof or open land facing the sun. As the sunlight is converted to electricity, the DC generated is sent to an inverter, which converts the Directing Current (DC) to Alternating Current (AC) power. The two varieties of solar house heating are:


  • Hot Water Solar systems


This system is generally the bigger version of the same kind of solar power energy of water heater. Similarly, the hot water heating system uses solar collector panels to heat the water. Then that circulates through tubing lacing through the panels. However, the water doesn’t store in smaller tanks instead the hot water is circulated through piping. Hence, it provides warmth to radiators or radiant flooring tubing throughout the entire home. 


  • Hot Air Solar Systems


This system is operated by gathering the air that has been heated by the sun striking down on a roof or an exposed floor and circulating it through the home. However, there are full house heating systems that use hot air rather than water or other fluid to transfer temperature around the house. Disregarding this system is solely designed to heat a single room only.


  • Solar Powered Ventilation fans


The Solar ventilation fans work under the power of the sun. It pulls superheated air out of the room. The heat is replaced by the cooler outside air. As a result, this reduces the amount of work done by Heating, Ventilation, and Air Conditioning system has to do to cool the area. Ventilation fans of any sort can be a good idea. 


  • Solar Transportation


The world is soon changing into solar dependency. Likewise, solar-powered vehicles will probably be the future. These vehicles operated on a battery that can be charged with a type of photo-electric panel system. 


Solar Energy Pros and Cons


The pros and cons are:


Advantages

Disadvantages

Reduces Household’s Carbon Footprints

Weather Dependent

Drops power bills

Higher initial cost 

Long time warranty and low maintenance cost 

Requires wider space

Diverse application

Correlated to some pollution

Versatile fixation

Panel deterioration


Advantages of Solar Energy


  • Reduces household’s carbon footprints


Solar Power Energy is taken as the cleanest source of energy. The energy solely uses the power of the sun’s rays to produce electricity or for heating. it doesn’t release any harmful gases into the environment. Thus, it aids in subduing the emission of carbon dioxide. 


  • Drops Power bills 


By producing power through solar panels, the power bills can be reduced. This energy doesn’t require any outside supply to work, so its maintenance and energy production costs are practically nil. The only cost associated is the manufacture and installation of the parts. This means that despite the large initial investment, there are no additional costs incorporated with its use, so the installation is recovered quickly. 


  • Long time warranty and low maintenance cost 


Well, the solar cells may be comparatively weak. However, they are protected under shatterproof tempered glass with flexible protecting cell components. Even hail storms can hardly cause anything more than minor damage. In insomuch, the maintenance costs are considerably low only if the instruction provided by the manufacturing while installing is fostered expertly. 


  • Diverse application


Solar Power energy isn’t limited to a single purpose. It can be used for multiple goals. This energy can generate electricity in those locations where the energy grids are inaccessible. Besides that, connecting the energy for running other digital devices is a unique factor. Solar thermal energy can heat the whole building with the heavy installation of solar power plants. 


  • Versatile fixation


One of the significant benefits is the solar panels can be installed in any location. Both vertical and horizontal distances that have no particular use can be suitable too. It requires simple and easy prospects in situating. Despite that, it just takes a maximum of 2 days to run under the energy. Even it can be run in remote areas where the installation of electrical distributing lines is improbable. 


Disadvantages of Solar Energy


  • Weather Dependent


The energy is wholly dependent on the sun. Although the energy can be tapped in cloudy and rainy weather, the efficiency will be completely low. Sometimes there would be raining or cloudy weather for more than a week or so. In such a matter, the energy system can be affected noticeably. 


  • Higher initial cost 


Though the energy has an easy installation process, the investment and fixation initially are costly. For example, to behold the power of a normal-sized house, the solar system of at least $20,000 should need to be purchased. This is an excessively high price by which people excuse giving attention to the investment of this energy. 


  • Requires wider space


Every advantage has a disadvantage in solar power energy. It says that the solar panels can be fixed in every place either rural or urban. However, the panels should have access to sunlight. For more electricity production, more solar panels need to be installed. At the same time, it needs a substantial sized area. 


  • Correlated to some pollution


This energy emits less pollution than other sources of energy. The transportation and installation of this energy system is somewhat linked with the release of greenhouse gases. The production of solar cells makes use of toxic metals. These are used inside the production plants but none of these merges in the environment. However, the hazardous products used in the manufacturing process indirectly attack the environment. 


  • Panel deterioration


Like any other goods, the solar panels can get damaged by ultraviolet radiation too. The different sources such as snow, condensation, or rain can bring the damage. Else, overheating can be another source of damage. The panels can’t handle the extreme heat. To cool down the extreme temperature, ventilation fans should be installed. Splashing water is strictly interdicted


Conclusion


Hence, solar energy isn’t just a great source for the environment but is broader succor in economical and social gains. This energy can be accessible in rural areas too. This results in faster development advancing in lower cost and efforts compared to other renewable resources. The components in up-raising the living standard always come after the advanced development automatically. This energy makes the world come narrower.


In the environmental aspects, the lesser emission of greenhouse gases in the atmosphere gets detected. The harnesses from the sun energy release no gases at all. Instead, solar power plants can easily collect the power with no purpose of harming the environment. Also, without impacting on health, land, water, and air including animals. For example, except using solar power, to get warmth the wood needs to be burnt. When the trees are cut down for firewoods, the animals lose the house. Nevertheless, solar power energy can rescue on preventing loss.


Elsewhere, the massively higher production of electricity and heat is not only for commercial companies or buildings. It is available for everyday use. For such, Residential scale solar comes in handy. It is installed on rooftops of smaller homes or backyard and can create about 5 to 20 kilowatts of energy. Likewise, Commercial solar power energy projects are designed for medium medium-sized The aim of this project is to provide on-site solar power to businesses and non-profit making organizations. And utility-scale projects are for larger companies that provide this energy to a bigger number of efficacy customers.


All things considered, the power of solar is immensely serviceable. It is the source of undeviatingly usable energy. As the sun revolves around the earth, every area of the planet receives an adequate amount of solar power. The capturing for the whole day can be more than enough for an entire year. Even at low latitudes, the power can be collected for cooking or driving steam turbines. Inclosing, solar is the only renewable source of energy that is proficient to supersede the supply of global energy from nonrenewable resources.


We hope you have enjoyed our content on Solar Energy. Do you think we missed something? Do you know of some other way this energy contributes worldwide? Feel free to comment below. We always appreciate your suggestions.