Renewable Energy Systems

Question: Discuss about the Renewable Energy Systems. Answer: Introduction The role of electricity on economic progress cannot be underestimated. For many years, non-renewable energy sources fossil fuels such as oil, natural gas and coal, have been used to generate electricity but their negative impacts on human health and the environment have become very damaging. This has led to development of renewable energy systems, including solar energy systems, wind energy systems, biomass energy systems, and hydroelectric systems. These systems generate electricity that is cleaner, safer, sustainable and cost-effective. If proper mechanisms are put in place, renewable energy systems will continue playing a significant role in reducing the global impact of climate change especially global warming. Technical aspects of renewable energy systems Design Renewable energy systems have to be designed by considering a variety of factors including, but not limited to: projected energy demand (capacity of the system); availability of land; availability of the energy renewable resources; and capital requirement. By considering these factors, the systems designed will supply adequate energy to meet the projected demand. The systems should also be designed to ensure maximum efficacy. Last but not least, these systems should be designed using advanced design tools Fundamental components Renewable energy systems comprise of multiple components used in the generation and supply of energy. This includes generators, inverters, collectors, etc. Each component has to be chosen correctly, analyzed, tested and installed accurately so as to ensure that the entire system functions as designed. The components must of the right size and materials so as to withstand internal forces and external conditions associated with energy generation and distribution. Most importantly is to ensure that all components are installed properly and tested before the system is allowed to operate. Power quality It is also important for the renewable energy system to generate and distribute energy that meets the required standards. For this to be achieved, all equipment used have to be certified meaning that they meet the required quality standards. The production process must also be to the required standards. The benefit of good power quality is that it will serve the intended use optimally. Good quality power is also attained by using the right size and quality of inverter. Equipment protection Most renewable energy systems are nowadays designed and built with an aim of connecting to the grid so that they can give out surplus energy. It is therefore important to re-evaluate the fault levels of the grid during the design stage and make necessary adjustments to the settings of the protection devices. Doing so will protect the renewable energy system when power supply by the grid is restored after an interruption. It is also important to ensure synchronization between the renewable energy system and the grid. This includes features such as their phase angles, frequency and voltages. Additionally, there should be facilities to automatically disconnect the renewable energy system from the grid when the former develops a fault or when frequency and voltage deviations/fluctuations are detected in it. Connection Renewable energy systems usually convert renewable resources, such as sunlight, wind, water and biomass, into energy. These systems must be constructed using appropriate components and apply the right technologies in generating energy. The components must also be integrated properly so that they can perform with maximum efficiency. If the system is connected to the grid, appropriate devices have to be used to as to ensure smooth and efficient connection. Supply Reliability It is important to ensure that the production and distribution of energy by the renewable energy system does not in any way adversely affect normal grid supply. The system has to be designed accurately and appropriate facilities installed prevent, detect and rectify defaults in a timely manner. In case of a fault, whether in the grid or renewable energy system, setting of the protection devices have to be chosen carefully so as to prevent the default of one system from affecting supply of the other system. Safety Many energy production and distribution systems, including renewable energy systems, have multiple safety concerns. This poses a great danger for people especially when normal energy supply is interrupted due to faults. Another cause of such dangers is when power supply of the national grid, which is connected with the renewable energy system, is interrupted. In this regard, the design of renewable energy systems must incorporate protection functions, such as anti-islanding (Joseph, 2005). Such functions are capable of automatically disconnecting systems that are connected to the grid if the energy supplied by the grid is interrupted. When supply of the grid gets restored, the same functions can automatically reconnect the system or the same can also be done manually using manual control. Maintenance Generally, renewable energy systems have relatively high initial costs and low maintenance costs. But low maintenance requirements result from proper design and installation of these systems. Therefore reliable components and durable materials have to be used so as to resist high mechanical strain, temperatures and pressures associated with these systems. With low maintenance, return on investment increases and payback time reduces. Monitoring and control This is another crucial technical aspect of renewable energy systems. Monitoring provides useful information on the production capacity of the system, which can be used to determine the necessity for expansion or strategies to improve the systems performance efficiency. Controlling determines the amount of energy to be supplied to specific users. It also determines when surplus power should be supplied to the grid. The systems have to be monitored and controlled using advance technological tools and facilities. Environmental issues associated with renewable energy systems There are quite a number of environmental issues associated with renewable energy systems. These issues have become the major bases of discussions on renewable energy. The main objective is to reduce or avoid negative impacts of renewable energy systems on the environment and increase positive ones. These issues also vary among different types of renewable energy system. By understanding these issues, it becomes easier to find ways of generating renewable energy that is cleaner and more sustainable. Changes in land use Construction of large renewable systems requires substantial amount of land. This means that people living near the site have to be relocated before the systems can be built. It also poses a great risk to the local habitat leading to habitat loss. When these systems are constructed, land use in the area usually changes. For example, large solar energy and hydroelectric systems require a lot of land and this land cannot be shared with other uses such as agricultural activities. It means that when such systems are constructed somewhere, most of the previous land uses will be changed or abandoned. When these systems start operating, there is the likelihood that more land in the nearby areas will be put into commercial and industrial uses. This is because availability of electricity activates establishment of industries and commercial businesses. Therefore the renewable energy systems may start competing with forestry, agriculture and human settlement for land. This also raises the conce rn of land degradation. One of the ways of resolving this issue is by selecting appropriate sites for the construction of renewable energy systems. Some of the recommended sites include abandoned quarrying land, brownfields, or existing transmission and transportation corridors (Union of Concerned Scientists, 2013). Changes in water use All renewable energy systems require some water for various purposes especially cooling. The amount of water required depends on several factors, including size of the system, location, design and the kind of cooling technology or system used. If these systems are constructed in an area, it means that their water requirements will be given a priority because the systems cannot operate without water. This may mean denying other people, industries, businesses, plants and animals access to water like before. The situation may worsen if the systems are put up in areas with scarce water. It means that they will start competing for water with other users such as people, animals, plants and industries. This issue can be resolved by ensuring that renewable energy systems are constructed in areas with abundant water for equal and effective water tradeoffs and also using appropriate dry-cooling technologies. Hazardous materials This is a major concern especially in solar energy systems. These systems use photovoltaic (PV) cells, which are manufactured using numerous hazardous materials and chemicals such as sulfuric acid, hydrochloric acid, hydrogen fluoride, acetone and nitric acid, among others. Sometimes these chemicals may find their way into the environment thus affecting human beings, animals, plants and other natural ecosystems. They also pose a great health risk to people who work in these solar energy systems as they can easily inhale chemicals. To overcome this issue and prevent its public health or environmental threats, renewable energy companies must ensure that they follow manufacturing laws. This will help in preventing release of these toxic materials to the environment through proper disposal and also protecting workers from being exposed to these chemicals. Global warming emissions Even though renewable energy systems are not directly linked with global warming emissions, these emissions come from other stages of the systems life-cycle. These stages include production and transportation of materials used by the systems, construction and assembly of the systems on site, operation and maintenance of the systems, and decommissioning and disassembling of these systems (Union of Concerned Scientists, 2013). Some systems such as geothermal systems require significant amount of energy for drilling and pumping water. Such activities can also cause different levels of air emissions. However, global warming emission estimates of renewable energy systems are very low compared to those of fossil fuels. Economics of the renewable energy systems Most people know about the environmental benefits of renewable energy especially those related with reduction of global emissions. However, majority of these people overlook the numerous social and economic benefits of renewable energy (Adnan Z. Amin, 2016). This may be because renewable energy is relatively new to many people hence they do not understand all its benefits. Additionally, most of the debates have been on how renewable energy can reduce negative environmental impacts associated with fossil fuels. Currently, about 80% of global energy is obtained from fossil fuels (David Timmons, Jonathan M. Harris and Brian Roach, 2014). This is because non-renewable sources have been for many years providing energy at a relatively low cost. Nevertheless, the cost advantage of non-renewable energy systems over renewable energy systems has been declining in the recent years. Based on the current investments and developments on renewable energy systems, the cost of renewable energy is projected to continue decreasing in the coming years, where non-renewable energy costs are likely to increase. Subsidies As a way of promoting production of renewable energy, governments and other private stakeholders have set up subsidies for renewable energy companies. These subsidies, which are billions of dollars every year, reduce the total cost of energy production. The advantage also goes down to consumers who pay less for electricity. This encourages more companies to construct renewable energy plants thus increasing production capacity. On the other hand, fossil fuel subsidies are gradually being phased out as a way of reducing commitment towards non-renewable energy. The renewable energy subsidies are growing very fast across the world and are continuing to bring significant long-term environmental and economic benefits. Changeability This is a major economic issue in renewable energy sector. It is almost impossible to match the energy demand with supply of renewable energy resources. This is because the wind may not blow sometimes, the sun may not shine at all during winter, water may be unavailable during droughts, or crops may fail leading to inadequate biomass. This means that matching the renewable energy supply and demand is very difficult. Inasmuch as demand can be predicted, supply cannot. For example, even if energy demand increases on a rainy day, supply of solar energy cannot be increased to match the demand. These factors make renewable energy systems more intermittent in terms of supply, which increases cost. One way of resolving this issue is through energy diversity. Combining two or more renewable energy systems, such as solar energy and wind energy, can boost supply consistency. Another approach is to increase production capacity of renewable energy systems so that surplus energy can be stored dur ing off-peak and be supplied when demand increases. Last but not least, having a robust national or international electric grid can also solve changeability problem. This will help in supplying power to areas experiencing low supply (where power is needed) from areas with high supply (where power is being generated) at that particular time. Increased job opportunities Renewable energy systems have created numerous job opportunities worldwide. According to a report released by IRENA (2015) in 2015, 7.7 million people were employed in the renewable energy sector globally. This was a significant increase from the previous year and the number is continuing to rise. The sector creates job opportunities both directly and indirectly. As the number of renewable energy plants increase, more people are employed in the design, construction, operation and maintenance of these systems. Others are also employed for installation and maintenance of small-scale systems, such as solar panels or photovoltaic cells, for smaller consumers. Once the renewable energy is generated, a lot more employment opportunities are created. This is because renewable energy systems supply energy to all areas, including remote areas that were previously not connected to grid. Availability of power in such areas drives establishment of industries and other businesses that create jobs. Falling costs The economics of renewable energy systems also entail analyzing various costs associated with investing in renewable energy projects. Typical costs of renewable energy systems are divided into various sections, including design, construction of the system, assembly, piping, storage facilities, control systems and distribution (POLYCITY, 2006). These costs include: capital costs, cost of capital, operating costs, levelised cost of energy (lcoe), capacity factor and marginal cost (Green Rhino Energy). Capital costs include costs incurred in the initial construction of the renewable energy plant and some main maintenance works that have to be done over the plants lifetime. These capital costs were initially high but have continued to reduce over the years as most government provide renewable energy subsidies and new technologies are also being developed to lower the costs Operating costs are costs incurred during normal operations and maintenance of renewable energy systems. These costs are very low in renewable energy systems compared to non-renewable energy systems. Capacity factor is the average output energy of a power plant to its potential peak energy. Considering the fact that renewable energy sources may vary from time to time and the plants may also be interrupted due to maintenance or faults, it is difficult for the capacity factor to be 100%. In most cases, the capacity factor for renewable energy systems is below 50%. Marginal cost is the amount of money that has to be spent so as to generate extra kWh, beyond the fixed costs included in the initial investment cost and operation cost. Since renewable energy systems do not require fuel and have very minimal maintenance requirements, their marginal costs are very low (sometimes almost zero). Cost of capital refers to the amount of money that renewable energy companies have to pay investors as their expected investment returns. Just like any other investment, renewable energy systems also have risks. But these risks can be reduced through proper legislation and constant supply of renewable energy. Levelised cost of energy (lcoe) refers to the price per kWh of electricity generated that zeroes the net present installation value. This means that lcoe of a renewable energy plant has to be higher than the sale price for the projected returns to be realized. Nearly all costs associated with production, distribution and use of renewable energy are falling. As the costs fall, the price of electricity also reduces meaning that end users now pay less. Net energy This is the ratio of energy available for final use to the quantity of energy needed to generate it. The net energy varies depending on conditions and production technology used. Renewable energy systems have very low net energy ratios because they use very little energy (if any) to generate energy. This is very advantageous because it lowers the total cost of energy. These ratios are continually reducing following the discovery of more advanced technologies aimed at reducing energy requirements of renewable energy systems. Social, legal and political issues related to renewable energy systems Some of the social, legal and political issues related to renewable energy systems are as follows Energy Security One of the main advantages of renewable energy is that it is sustainable and therefore renewable energy sources will never be depleted. In this regard, renewable energy systems increase energy security of countries because each country can generate her own power and be self-reliant (Select Committee on Economic Affairs, 2008). Job and wealth creation Construction of renewable energy systems in a particular area must benefit local residents. Considering the anticipated economic benefits of such projects, many ignorant local residents have been forced to sell their land at throwaway prices on threats that they would be evicted if they refuted. Local communities must be allowed to settle in their areas so that they can benefit from the income generation opportunities related to this kind of energy projects. The projects will create jobs for the local residents and help them create their own wealth. Proper relocation and compensation Construction of large renewable energy systems usually require a substantial amount of land (David et al., 2002). This may necessitate relocation of some people within the selected sites. In such cases, the people must be resettled without being forced and be compensated accordingly. The amount of compensation has always remained to be a big issue of discussion Creating awareness It is also important to involve communities during the planning stage of renewable energy projects so that local people can be fully informed about the upcoming project. They should be informed about the advantages and disadvantages of such projects. This will prevent conflicts of interest especially among local communities when the project kicks off. Legislation There is also need to formulate comprehensive guidelines that will regulate activities associated with renewable energy systems. For instance, emissions limits from renewable energy systems must be set and any company exceeding them should be penalized heavily. This will ensure that the energy generated is clean and safe. The systems must also operate under safe environments. Political unpredictability Energy is a very essential driver of any economy. It has been claimed that fossil fuels have been the main course of political conflicts and wars in countries rich in these resources. If people shift from fossil fuels to renewable energy, there is a likelihood that countries with vast resources to generate renewable energy may start experiencing conflicts and wars. Global energy and economic crises One of the real alternatives of overcoming the looming problem of energy supply across the world is by increasing investments in the renewable energy sector. However, renewable energy systems are not reliable (because of changes in sunlight intensity, wind, rainfall patterns and biomass production) in matching energy demand and supply. If the whole world relies on renewable energy systems for energy supply, there may be a shortage of energy supply. This will cause global energy and economic crises. Social acceptance Transitioning from fossil fuels to renewable energy systems is not as easy as it may sound (Rolf et al., 2007). One of the reasons is because a lot of investments have been made in the fossil fuel industry. In addition, antagonists of renewable energy usually amplifies its disadvantages thus making ignorant people oppose it too. Conclusion A lot of investments have been made in renewable energy sector. This sector is potentially posed to prevent and reduce various negative impacts associated with fossil fuels. Renewable energy systems also play a key role in reducing climate change, especially global warming. By analyzing different issues associated with renewable energy systems, it becomes easier to establish ways of improving these systems. With proper formulation of policies to govern production, distribution and use of renewable energy, the global population will enjoy a series of benefits, including being connected to power cost effectively, improved health, improved air quality and they will avoid the irreversible and dangerous climate change. References: Akella A.K., Saini, R.P. Sharma M.P., February 2009, Social, economic and environmental impacts of renewable energy systems, Renewable Energy Journal, Vol. 34, Issue 2, pp. 390-396. 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