Chapter 1 Introduction
The notion of going green is not strictly a new technological concept, and any naturally occurring and theoretically inexhaustible energy such as wind, biomass, and solar, tidal, wave, hydroelectric power that is not derived from fossil or nuclear fuel is referred to as renewable energy. The relevance of these emerging fields became more pronounced when the need to produce clean, safe and efficient energy devices without trading off environmental friendliness arise. The current electricity production from fossil fuels like natural gas, oil and
coal are large and environmentally unfriendly. Thus, because they bear the limitations that they rely on non-renewable energy sources. Many developing countries cannot afford these conventional energy sources, and in some of these locations nuclear power is considered a threat or more or less an unacceptable risk. The need for an environmentally friendly and cost effective electricity generating scheme is invariably obvious and would be more alarming in the nearest future. A proven remedy to the ever-increasing energy production problem is Solar Energy. It is inexhaustible and abundant renewable source of energy that only needs to be harnessed to be utilized by man. Solar power plants in use in the world are modelled to transform solar irradiation into electrical energy through any one of a number of cycles or natural phenomenon. A number of solar power plants have the ability to encase or store sufficient energy during the day in order that, it can be used at night when there is no sunlight. However, the practical viability of these storage capacities is seemingly too high. Solar energy is a renewable and clean energy resource, which produces neither greenhouse effect gases nor hazardous wastes through its utilization. Of many techniques utilizing solar energy, solar power generation seems to be one of the most attractive.
Electric power can be obtained from solar energy by two means, photovoltaic effect and solar thermal generator. Solar cells form a semiconductor unit to produce electric current based on photovoltaic effect, and the solar thermal generator, is always driven by steam generated by large scale solar concentrator. Sensible technology for the wide use of renewable energy must be simple and reliable, accessible to the technologically less developed countries that are sunny and often have limited raw materials resources. It should not need cooling water and it should be based on environmentally sound production from renewable or recyclable materials. The solar tower meets these conditions. Economic appraisals based on experience and knowledge gathered so far have shown that large scale solar towers (greater than 100 MW) are capable of generating electricity at costs comparable to those of conventional power plants. This is reason enough to further develop this form of solar energy utilization, up to large, economically viable units. In a future energy economy, solar towers could thus help assure the economic and environmentally benign provision of electricity in sunny regions. In the paper an overview is given over solar updraft tower theory, practical experience with a prototype, and economies of large scale solar updraft tower power plants.
Fig 1.1 Design View of a Solar Updraft Tower
Chapter 2 Functional Principle
The solar tower’s principle is shown in Fig 2.1. Air is heated by solar radiation under a low circular transparent or translucent roof open at the periphery; the roof and the natural ground below it form a solar air collector. The amount of radiation sufficient enough to drive the cold air beneath the solar collector is indeed the sum of all possible types of radiation, such as. 1. Direct radiation 2. Diffuse radiation and, 3. Reflective radiation. In the middle of the roof is a vertical tower with large air inlets at its base. The joint between the roof and the tower base is airtight.
Fig 2.1 Schematic of...
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