Global Dimming

The article on global warming would not be complete without mentioning global dimming as a very important phenomenon. Global dimming is the gradual reduction in the amount of solar radiation reaching the earth's surface, due to the increased amounts of fine particles in the atmosphere caused by human activities throw the processes of fuel combustion. Many researches have shown that the amount of radiation reaching the ground is decreased by an average of 2-3% per decade, and in some areas even more. At the moment, scientists can not find the cause of drastically reducing the amount of solar radiation that reaches the ground given that the amount of particles that entered the atmosphere as a result of burning fossil fuels can not be sufficient for such drastic changes.

Technology for Wind Energy Production

In this article, the principle of energy conversion is described as well as ways to connect the windmills to the power grid. There are various potential applications of energy derived from wind, and one widely spread is a source of energy for the household.

Technology for Solar Energy Production

Solar Cell

Solar cells are semiconductor structures which convert solar radiation in into electrical energy. Solar cell is composed of a large number of diodes, p-n junctions. The process in the middle is Photovoltaic conversion. In this process electron-hole pair is generated due to the incident light. This amount of photon energy is sufficient to move electrons from the valence zone into conductive zone. When it comes to the ways how solar cells can be connected, serial, parallel, or combined connection is possible. However, it all depends on the projected power of the cells. The voltage that is obtained at the output depends on the cell type and can be in range of 600-700 mV, with a current density of about several tens of mA/cm2. These parameters strictly depend on the strength of solar radiation.

Production of Biofuels based on Algae

There are global efforts to reduce dependence on fossil fuels and find economically acceptable alternative fuels and thereby significantly reduce emissions of harmful carbon dioxide into the atmosphere. One of the alternatives are biofuels. Biofuels are due to its similar chemical  structure with petroleum products is quite good alternative to fossil fuels and the use of biofuels results in lower emissions of carbon-dioxide into the atmosphere. Therefore, biofuels are environmentally much more acceptable than competing fossil fuels. Decreased total carbon dioxide emissions from biofuels are the result of closed carbon circle - plants and algae use atmospheric carbon dioxide to grow, and then by using biofuels, the carbon dioxide is returned back into the atmosphere. The carbon-dioxide emmison produced by burning fossil fuel goes in only one direction - from the earth to the atmosphere, which has direct impact on increase greenhouse gases in atmosphere.

BIOFUELS

Many people consider biofuels as a replacement for traditional fossil fuels in the times to come. There are many reasons why this point of view is gaining more and more in popularity. One feature that quailifies biofuels for perfect renewable energy source is the fact, that biofuels can be produced easily and this way one might achive reduction of dependence on imported energy. However, nothing is ideal, and that includes biofules. Some people argue that biofuels could be extremely dangerous for humanity, owing to the fact that no detailed study of the origin and properties of the biofuels have not been conducted. We will have to resolve what are positive and negative sides of using this type of energy source, but also the potential dangers and the impact that biofuels will have on the total world economy.

Ocean Energy

Energy consumption in the world is increasing rapidly. Reserves of fossil fuels are diminishing. Turning the use of alternative energy sources is an imperative of the modern era. Not only is it necessary to increase the energy production, but that energy should be clean or environmentally friendly.Energy production should not cause environmental problems such as global warming and air pollution. One of these new renewable energy sources could certainly be the energy of the ocean whose importance will certainly be much higher in the future.

Geothermal Energy

In its essence, geothermal energy is simply heat of the Earth. The heat in the interior of the Earth is due to the formation of planets from dust and gases. In the rocks, process of continuous radioactive decay of elements takes place, which as a result has regeneration of this heat. It is therefore correctly to say that geothermal energy is a renewable source of energy. The heat is from the interior to the surface transmitted by means of water or steam. This component is renewable given the fact that water from the rain penetrates deep into the crevices and there is then heated and circulated back to the surface, where it appears in the form of geysers and hot springs.

Global Warming

In the previous century, the temperature on Earth has increased an average of between 0.6 °C. The hottest recorded year was 2005. If carbon dioxide emissions continue to grow, we can expect an increase in the average temperature of up to 6 °C. Greenhouse gases are collected in the upper atmosphere and have a double impact on the temperature of the Earth's surface. The first effect is a direct rejection of one part of the solar radiation back into space, and the second impact is reflecting a portion of solar radiation that bounced off the Earth's surface back to Earth. This second effect is called the greenhouse effect and this effect is responsible for maintaining a favorable temperature on the surface of the Earth. If there were no greenhouse effect, the average temperature at the Earth's surface would be about -19 ° C, rather than about 15 ° C, which is currently the case. One might say that solution for the problem of global warming is easily trackable: reducing the use of fossil fuels and minimizing deforestation, thereby reducing the concentration of greenhouse gases in the atmosphere. However, in practice this is not feasible due to the inadequate development of alternative energy sources.

Bioenergy

The term bioenergy refers to the energy produced using solid, liquid and gaseous biomass products. Hence, one might reffers to biomass as a renewable energy source, based on number of products of plant and animal origin. Biomass is the biodegradable fraction of products, waste / by-products and residues from agriculture (including substances of animal and plant origin), wood industry, as well as the biodegradable fraction of industrial and municipal waste.It can be directly converted to energy by combustion and thus producing steam for heating in industry and households and gaining energy in smaller thermal power plants. Alcohol fermentation is so far the most advanced chemical conversion of biomass. Biogas is the result of fermentation without presence of oxygen consists of methane and carbon and can be used as fuel, and other modern procedures of energy biomass include pyrolysis, gasification and getting hydrogen.

Water Energy

Water energy (hydropower) is the most important renewable energy source. Water as an energy source is considered to be renewable because of the water cycle in nature. Radiation of the sun causes the evaporation of water from the oceans and rivers and its transformation into water vapor. When water vapor reaches the colder air in the atmosphere, it condenses and creates clouds, thus creating rain or snow and renewing the water in the oceans and rivers. Gravity moves the water from a high pitch to low. The power of flowing water can be very large.

Wind Energy

If one considers the fastest growing segment of energy production, the answer would be definitely wind energy production from renewable sources. Actually, wind energy currently represents the most common form of renewable energy in the world. Wind energy originates form solar energy. In its essence, it is transformed form of solar energy. The thing is that sun when radiates, unevenly heats different parts of the Earth, which as a result has different air pressures. Consequently, tendency to equalize air pressures creates wind. In some parts of the Earth, blow so-called constant winds and these areas are the most cost-effective in terms of wind energy production. Good positions for wind turbines installation are ocean coast and high seas. Offshore stands out as the best position because of the constant winds, however costs of installation and energy transport represent large obstacle for  such exploitation.

Solar Energy

The Sun is star in our closest proximity and provides almost all available energy on Earth. Solar energy originates from nuclear reactions in core of the sun, where the temperature reaches 15 million Celsius degrees. It is all about fusion, where hydrogen atoms merge and as a result helium is produced with large amounts of energy released. Every second about 600 million tons of hydrogen are being converged into helium, wherein the weight of about 4 million tons of hydrogen is being transformed into energy.