Energy is one of the most fundamental concepts in the 20th century and one of the most important concepts in our daily life. Fossil fuels and other traditional forms of energy have been the major source of energy for a long time. Combustion of fossil fuels produces harmful gases like carbon dioxide that causes greenhouse effect, which results to global warming. Global warming is a serious pollution problem caused by continued use of fossil fuels. Environmental pollution because of these traditional forms of energy is one of the major touching issues in the 21st century . It is also important to note that, as a result of environmental pollution and escalating prices of fossil, issues associated energy, sustainability and renewability are attracting more and more attentions not just from scientists but from any perspective towards the future. Thus, the idea of alternative energy sources that are environmentally is gaining popularity especially in the building industry because buildings consume large portion of electric power from the grid and consequently contributes to environmental pollution through emissions of carbon. In fact, energy conservation by use of alternative energy sources is attracting more attention, with the aim to come up with renewable, energy efficient systems that are sustainable especially in the design of buildings. Wind energy is one of these alternative forms of energy. Alternative energy sources are those sources that we cannot exhaust because nature replenishes them constantly; they include geothermal energy, hydroelectricity, wind energy, wave power, tidal power and solar energy. However, this research paper is concerned with wind power.
The aim of this task is to explicate the various methods through which engineers can use wind power in designing energy- and resource-efficient buildings that are environmental friendly. The paper will look into the several ways through which engineers can incorporate wind energy in order to achieve a zero-energy building. Finally, this research paper will explicate the economic and environmental benefits of wind energy systems in buildings.
Engineers cannot underestimate issues pertaining to energy, renewability, efficiency, sustainability in the design of modern building structures. This is because carbon emanating from this building appreciably contributes to declension of climate. Buildings greatly affect energy consumption in most countries. They consume about 37 % and 67 % of all the primary energy and electric energy respectively in provision of services as shown in Fig. 1. Therefore, it is inevitable for engineers to look for ways to lower the energy requirements in buildings and at the same time enhance energy efficiency, sustainability and renewability. The figures below shows the total energy consumption breakdown and energy break down for a building respectively.
Figure 1: Buildings share of the total energy
Figure 2: Typical Building energy consumption breakdown
According to Figure 2, it is clear that heating, cooling, air conditioning and ventilation consumes the largest percentage of energy. Lighting, domestic hot water production lifts, catering, and elevator's pumps amongst others consume the remaining percentage. Their main aim is to ensure human comfort by allowing their bodies to perspire. Wind power is the other form of energy that modern building should utilize. It is worth to note that, wind power is one of the most promising energy technologies that houses and building should rely on to reduce electric consumption. The following section captures the various ways that we can use wind power.
Engineers should install wind turbines especially in windy areas in order to trap energy from the wind. The air currents run the wind turbines that in turn run the electric generator. For instance, at 120 feet (33 meters) above the ground, wind turbines will the advantage of the high velocities and less turbulence of the wind. The wind turbine blades act as an aerofoil. That is when the wind is blowing; low-pressure region/pocket is formed on the lower side of the blade. This low-pressure zone results to a lifting force as the blade is pulled towards it. The lift force is greater than the drag force of the wind, the combination of these two forces makes the turbine blades spin like a propeller. The shaft of the turbine blade is coupled to a generator, which generates electricity. Engineers must install wind turbines high enough to utilize high wind velocity and low turbulence because wind turbines efficiency is a function of wind velocity. That is, engineers should select the best site for installing the wind turbines. Finally, it is important to note that installation of wind energy is a capital-intensive venture. However, this is justified by the huge saving in electrical load and in reduced carbon emission. In addition, it is important to note that wind energy requires little maintenance and thus cheap to run/operate. It is important to note that wind turbines can be used as standalone application or can be connected to the grid. In addition, the can be coupled to photovoltaic (solar) power system. The wind energy potential in the globe is five times the total energy generated globally. Thus, we can increase the percentage of electricity generated by wind power by installing modern Wind turbines of up to 5mw rated power in areas of high wind potential such as highlands and off shores.
Figure 3: Wind turbine
Use of passive (wind powered) air conditioning systems
For effective and environmental friendly air conditioning systems, the design engineer should consider parameters such as materials and orientation of the building to the direction of wind currents at the design level in order to facilitate passive air conditioning. In fact, air velocity has an influence on the design of the building. Passive air conditioning systems help to reduce the amount of electric energy consumption. Figure 3 presents the various parameters of a passive air conditioning system. Passive designs also incorporate the concepts of natural airflow without using of mechanical equipment such as fans for energy efficiency and reduction in energy consumed . Research has shown that Passive designs reduce energy consumptions by about 70 % by reducing the use electric heating and air conditioning systems. According to International Energy Agency, engineers should use passive designs and efficient electrical energy systems to design modern buildings. This is because passive designs reduce energy consumption by utilizing renewable energy sources such as wind currents, solar energy
Figure 4: Passive air conditioning parameters
Hybrid air conditioning systems
In order to maintain high quality environment in a building at night and during still days, buildings should make use hybrid air conditioning systems and refrigerating systems that incorporate both artificial and passive air conditioning. Artificial air circulation mechanisms should enable circulation of air. Designers should maximize the use of passive solar energy for space cooling and air conditioning. Passive air conditioning systems utilizes wind currents and solar energy and the concepts of natural air flow without using of mechanical equipment such as fans in orders to give energy efficient and quality indoor environment. This implies the designer must selection the best orientation of the building so that walls, floors and window are able to collect and distribute heat energy from the sun in winter and vice versa during the summer. Figure 4 presents the various elements of a hybrid air conditioning system.
Figure 5: Hybrid air conditioning system
This paper notes that issues associated with energy such as energy efficiency and energy conservation are attracting more attention, with the aim to come up with renewable, energy efficient systems that are sustainable especially in the design of buildings. This is because activities in buildings consume a bigger percentage of the total energy and contributes to declension of climate change through emission of carbon dioxide. Because of these, this research paper finds that a modern design should focus on energy efficiency, renewability and sustainability. This research paper observes that housing facilities can appreciably use wind energy to supplement the energy from the grid. In addition, research paper acknowledges the use passive cooling and air conditioning systems that can result to reduction in energy consumed. This is because air-cooling and air conditioning systems consume a wider portion of the total electric load, as opposed to other uses.
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