Solar Energy Technologies

Without energy, life on the planet is impossible. It can be derived from natural resources such as coal, natural gas, or uranium, and transformed into a favorable form, for example, light or heat. The world around can find various forms of energy storage. However, solar energy is the most important for a person. It represents a huge resource potential that is higher than the one of mineral resources.

Already the ancient people thought that the life on Earth was generated and inextricably linked with the sun. In the religions of various peoples inhabiting the Earth, one of the most important gods was always the Sun God, who granted life-giving warmth to all existing organisms. Indeed, the amount of energy reaching the Earth from the nearest star is enormous. In just three days, the sun sends the Earth as much energy as it is contained in all explored reserves of fuel. However, only a third of this energy reaches the Earth. The other two-thirds are reflected or scattered by the atmosphere. Nevertheless, even that part is more than fifteen hundred times greater than all the other energy used by people. In such a way, solar energy and renewable raw materials represent a huge resource potential, which is much higher than the one of mineral resources. The aim of the research paper is to reveal advantages and disadvantages of solar energy, as well as currently available technologies that use this kind of energy.

General Notion on Solar Energy

The sun gives a tremendous amount of energy. Solar energy is a source of life on the Earth. The sun provides life to all organisms. Despite the fact that the amount of solar energy is extremely huge, only a small part reaches the Earth. Nevertheless, even that part is enough to exceed the potential of mineral resources. In the future, it is possible to replace the full potential of mineral resources by solar energy.

The sun is a specific hydrodynamic object with the diameter of 1,390,000 kilometers. It is formed from a cloud of gas, mostly hydrogen. “About 74% of the sun’s mass is hydrogen, 25% is helium, and the rest is made up of trace quantities of heavier elements” (Kalogirou). The temperature of the subsoil thereof is so high that it allows fusion of hydrogen into helium. This synthesis occurring in the interior of the sun releases energy in the form of high-frequency electromagnetic radiation. Being reradiated gradually, it comes to its surface. Rays reaching the Earth come from a thin surface layer of the sun, namely a photosphere. Electromagnetic radiation of the solar photosphere propagates in cosmic space with the light velocity in a form of divergent beams.

The power of solar radiation is very high. “Energy from the sun in the form of solar radiation supports almost all life on earth via photosynthesis and drives the earth’s climate and weather” (Kalogirou). It constantly heats the land and water bodies and ensures the life of animals and plants. Mahaney claims that “solar energy is used for many purposes that are important to life on Earth” (p. 6). Part of the solar energy is stored in the bowels of the Earth in the form of coal, oil, natural gas, and other minerals. It underlines the role of the sun as a primary energy source.

The quantity of solar energy transferred to the Earth’s atmosphere is greater than to its surface. Moreover, the proportion that can be used is even less. However, solar energy and renewable raw materials are a resource potential that exceeds by far the one of mineral resources. Each year, the volume of the sun energy is in 15,000 times excess over the annual consumption of nuclear energy and energy from fossil sources. For example, it gives six times more energy to Italy than it is used in the course of the year worldwide. The annual production of flora photosynthesis exceeds 10,000 times the annual performance of the chemical industry all over the world. This means that in the future, it is possible to replace the full potential of mineral resources by solar energy resources.

Available Technologies

A new achievement in the field of passive use of solar energy is architectural planning and design solutions for buildings thus ensuring a maximum use of daylight. Therefore, this planning reduces the cost of artificial lighting. The use of daylight will be rational if it provides compact space-planning solutions of the building reducing heat loss. Concerning the active use of solar energy, there are solar collectors and solar cells. They consume solar energy and transform it into heat.

Solar energy can be helpful when using passive and active solar energy systems. The most elementary means of the passive use of solar energy is a dark-colored water tank. Accumulating solar energy, a dark color transforms it into heat. In such a way, water is heated. However, there are more effective practices concerning passive use of solar energy. “The term passive system is applied to buildings that include, as integral parts of the buildings, elements that admit, absorb, store, and release solar energy and thus reduce the need for auxiliary energy for comfort heating” (Kalogirou). In construction technologies that consider climatic conditions and selection of construction materials, solar energy is used for cooling, heating, and lighting of buildings.

In the basis of active solar energy systems, there are solar collectors. The collector, consuming solar energy, transforms it into heat. Through the coolant, it heats buildings and water. It can also be transformed into electrical energy. Solar collectors can be used in all processes in industry, agriculture, and domestic use. The main element of the collector is a thermally insulated plate made of any material that conducts heat. The plate is painted in a dark color. Solar rays pass through the transparent surface and heat the plate. Thereafter, the air flow transmits heat into the room. Air passes by the natural convention or the fan that improves heat transfer. However, the disadvantage of this system is that it requires additional costs for the fan. The collectors work during daylight hours; therefore, they cannot replace the main source of heating. However, if to mount the collector in the main source of heating or ventilation, its efficiency increases disproportionately.

Solar collectors can be flat and vacuum. The collector consists of an element that absorbs solar energy, a cover (glass with low metal content), a pipeline, and an insulating layer. The transparent cover protects the body from adverse climatic conditions. Inside the body, the panel of the absorber of solar energy is connected with the coolant which circulates through the pipes. The conduit may be in a form of a lattice or serpentine. Coolant moves along it from the input to the output gradually heating the nozzle. The panel absorber is made of metal – aluminum or copper. The collector catches heat turning it into heat energy. These collectors can be built into the roof, positioned on the roof of the building, or arranged separately.

Vacuum collectors can be used year-round. The main element of collectors is a vacuum tube. Each of them includes two glass tubes. Pipes are made of borosilicate glass. The inner one has a special coating that absorbs heat with minimal reflection. The air is exhausted from the space between the tubes. A barium getter helps to maintain the vacuum. In good condition, a vacuum tube has a silver color. If it is white, it means that the vacuum has disappeared, and the tube should be replaced. The vacuum collector consists of a set of vacuum tubes and transfers the heat to the storage tank via non-freezing liquid, coolant.

A solar cell is a set of modules. It receives and transforms solar energy, including the thermal one. Solar cells, first used on space satellites, can generate electricity continuously or accumulate it for the future use. The advantages of solar panels are the maximum simplicity of design, easy installation, and minimum requirements for servicing. In addition, they do not require additional space. The only condition is not to obscure them for a long time and remove dust from the working surface. Modern solar panels are able to operate for decades. They produce energy throughout the daylight hours even in cloudy weather. Solar cells have several drawbacks in the application, including sensitivity to high temperatures and contaminants as well as high price.

Polishing Your Writing to Make it Shine

In modern architecture, there are houses with built-in rechargeable sources of solar energy. Solar cells are installed on the roofs of buildings or on special supports. These buildings use a quiet, reliable, and secure source of energy, namely the sun. Solar energy is used for lighting, space heating, cooling, ventilation, and power generation.

Environmental Advantages and Disadvantages

There are many benefits of solar energy. One of its biggest advantages is that it is inexhaustible. The reserve of natural material is not endless. Therefore, scientists explore various means of receiving energy. A healthy environment is an important aspect for the prosperity and improvement of the lives’ quality not subjected to the threat of climate change. Energy production from renewable energy sources is an alternative to the use of fossil fuels and a key element in the fight against global warming. Nevertheless, there are also several environmental disadvantages of using solar energy. Firstly, the manufacture of solar cells contains hazardous substances, which in any way can harm nature. Secondly, there is the irregularity of solar energy, as it cannot operate in dark time of a day.

Each direction of alternative energy has a number of advantages and disadvantages, and solar energy is not an exception. Among the benefits of solar energy is the fact that its raw material, the sunlight, is inexhaustible. At this rate of use, world reserves of coal and gas can be exhausted in the next 100 years. It is estimated that in not explored deposits, reserves of fossil fuels would be enough for two-three centuries. However, future descendants would be deprived of energy, and products of combustion would inflict enormous damage to the environment. Therefore, the development of consuming solar energy is extremely significant. Ollhoff states that “it won’t provide 100 percent of our electricity needs in the foreseeable future, but it could provide a large part” (p. 4).

In the light of recent trends in the struggle for environmental cleanliness of the Earth, solar energy is the most promising sector, which partially replaces energy from non-renewable fuel resources. “The greatest advantage of solar energy compared with other forms of energy is that it is clean and can be supplied without environmental pollution” (Kalogirou). Thus, solar energy acts as a principal step towards protecting the climate from the global warming. Sunlight is a clean and safe source of energy as opposed to fossil fuels and nuclear energy. One of the main tasks of the new century is to reduce the anthropogenic impact on the Earth’s climate, and the alternative is the solar energy. Solar power stations, solar and thermal panels, solar ponds, and solar-hydrogen energy are the most striking landmarks, which can be called a ‘tomorrow day of energy.’

Nevertheless, a question of the absolute safety of solar energy for the environment is controversial. The manufacture of solar cells contains hazardous substances, which in any way can harm nature. Ready-made solar cells contain toxic substances such as lead, cadmium, gallium, and arsenic. The service life of solar cells is approximately fifty years. Therefore, there is an issue of subsequent processing of modules. Moreover, the disposal problem solving is still not found. A significant disadvantage of the process of obtaining solar energy is the irregularity. Solar systems cannot operate at night. Evening stations efficiency decreases. “However, the availability of solar radiation is limited in to daylight hours, therefore, it is necessary to store the electricity produced during the day in order to be able to use it during the night as well” (Clini, Musu, & Gullino). The lack of sunlight and its excessive emission reduce the effectiveness of the system as a whole. Thus, it is necessary to provide additional cooling modules. However, new developments and technologies appear yearly. Scientists hope that all these disadvantages are temporary.

Economic Advantages and Disadvantages

Nowadays, solar energy is a profitable business. Every investor has the possibility to invest in it. Nevertheless, this business is extremely expensive. Solar photovoltaic elements and solar panels cost a lot. Nowadays, solar energy is more expensive than that obtained by conventional methods. Nevertheless, scientists constantly develop new technologies that can help reduce the costs.

In many countries, citizens can build their power plants and sell electricity to the public network due to the energy strategy and planned tariff policy. Greece is among the most profitable places in Europe for the construction of solar power plants. The conditions for foreign investors are legal and favorable, and they have the ability to invest in the profitable business regardless of a country of residence. It is one of the main economic advantages of using solar energy. Kalogirou notes that “another factor of considerable importance in many countries is the ability of renewable energy technologies to generate jobs” (p. 13). The job relation is connected with the creation and construction of collectors.

The biggest drawback to the solar energy use is the cost of the technology. Solar photovoltaic elements and solar panels are extremely expensive. Using this technology in order to generate electricity on a large scale is very expensive, at least at the beginning of the XXI century. At present, solar energy is more expensive than that obtained by conventional methods. Scientists hope that the experiments conducted in plants and stations will help solve economic problems. Much depends on the government policies of a particular country, as well as the price of carbon fuels. Only Japan and Germany have invested the money capital in solar energy.

Political Legislation

Currently, in many countries worldwide, there are various programs for the development of solar energy which are supported by the state. For example, in Germany, there is a program 100 000 Solar Roofs. European architects developed the European Charter for solar energy in architecture and construction. In Asia, there are also systems of solar collectors in the construction of buildings and the use of solar energy in industry. One of the conditions for the entrance the European Union is the increase in the share of alternative sources in the energy system of every country member of the Union.

Solar systems are environmentally friendly. People around the world begin to abandon the use of traditional fuels due to the rising prices for oil and gas. For example, in Germany, 47% of homes had solar collectors for water heating in 2004. In many developed countries, there are state programs for the development of solar energy such as 100 000 Solar Roofs in Germany and Million Solar Roofs in the United States. In 1996, architects in Germany, Austria, Great Britain, Greece, and other countries developed the European Charter for solar energy in construction and architecture. In Asia, China is the leader. On the basis of modern technologies, there are systems of solar collectors in the construction of buildings and the use of solar energy in industry. One of the conditions for accession to the EU is the increase in the share of alternative sources in the energy system of the country. In 2000, there were 60 million square kilometers of solar collectors worldwide. By 2010, the area increased to 300 million square kilometers (Kalogirou).

Conclusion

Humankind has long been using the sun energy. The sun is an inexhaustible and environmentally friendly source of energy. Currently, the solar energy is used mainly in two ways, active and passive. Every method has its advantages and disadvantages. There are also drawbacks and benefits of solar energy regarding environment and economy. However, despite some disadvantages, solar energy is a source of life on the Earth that will be the safest in the future.

A person uses the sun’s heat since time immemorial. Industry and science aim to create machines and mechanisms that are less power-consuming and with higher efficiency. It allows to dispose the available resources properly. However, the most appropriate is the use of technologies related to renewable energy. The sun is the most accessible and inexhaustible among the sources of energy that nature gives to people. Nowadays, the possibility of using eco-friendly, widely available, and renewable solar energy attracts an increasing attention. Solar energy refers to renewable energy sources. It is one of the environmentally friendly energy sources. Solar energy does not pollute the environment.

Nevertheless, the manufacture of solar cells contains hazardous substances, which in any way can harm the nature. There are also economic advantages and disadvantages of solar energy. In many countries worldwide, there are numerous legislative programs supporting the usage of solar energy. The possibility of solar energy using is practically unlimited. Nowadays, scientists around the world are working to develop systems that enhance the use of solar energy.