Renewable Energy System Design

Ziyad Salameh

• Publisher: Academic Press
• Year: 2014
• ISBN:
  9780080961675
• Topic: Technology & Engineering
• Subtopic: Renewable Power Resources
• Index: Technology & Engineering

The limitation of fossil fuels has challenged scientists and engineers to search for alternative energy resources that can meet future energy demand. Renewable Energy System Design is a valuable reference focusing on engineering, design, and operating principles that engineers can follow in order to successfully design more robust and efficient renewable energy systems. Written by Dr. Ziyad Salameh, an expert with over thirty years of teaching, research, and design experience, Renewable Energy System Design provides readers with the "nuts and bolts" of photovoltaic, wind energy, and hybrid wind/PV systems. It explores renewable energy storage devices with an emphasis on batteries and fuel cells and emerging sustainable technologies like biomass, geothermal power, ocean thermal energy conversion, solar thermal, and satellite power. Renewable Energy System Design is a must-have resource that provides engineers and students with a comprehensive yet practical guide to the characteristics, principles of operation, and power potential of the most prevalent renewable energy systems.

• Explains and demonstrates design and operating principles for solar, wind, hybrid and emerging systems with diagrams and examples
• Utilizes case studies to help engineers anticipate and overcome common design challenges
• Explores renewable energy storage methods particularly batteries and fuel cells and emerging renewable technologies

Chapter 1

Factors Promoting Renewable Energy Applications

Abstract

Recently, global warming, pollution, and high oil prices have forced politicians, utility companies and the general public to pay more attention to renewable energy sources (RES) such as wind, photovoltaics, and biofuels. In today’s world, there are many reasons to support an enormous interest in renewable energy and to move away from conventional energy sources. The main reasons are:

• High oil prices; oil prices are rising higher and higher because demand exceeds the supply

• Impact of fossil fuel usage on the environment, which manifests itself in:

• Air pollution from transport, automobiles, and power stations has made cities hazardous to health, especially that of our children

• Acid rain: When nitric oxides and sulfur oxides combine with water in rain clouds, they form acid rain

• Global warming caused by the greenhouse effect

• Security of supply

Keywords

global warming

acid rain

air pollution

security of supply

1.1 Introduction

Recently global warming, pollution, and high oil prices forced politicians, utility companies, and the general public to pay more attention to renewable energy sources (RES) such as wind power, photovoltaic, and biofuels.

RES are environmentally friendly sources of energy; they form the backbone of distributed generation systems. Interest in them during the recent decade has been reflected in many academic studies, which provide more information on new ways of using renewable energy in addition to the traditional, isolated, stand-alone systems.

The term distributed generation systems (DGS) refers to a system that consists of many smaller generating plants located close to the major loads, as opposed to a few large centrally located power stations. A distributed generation system can significantly reduce transmission loss since the power source is located physically closer to the load. Other advantages of DGS are the increased reliability of the power supply because there is less dependence on a few major transmission lines over a large geographical area and reduced capacity of the main transmission lines and transformers.

In today’s world, there are many reasons that support enormous interest in renewable energy and the move away from conventional energy sources; the following are the main reasons:

• Higher oil prices—oil prices are going up and up because demand exceeds supply.

• The impact of fossil fuel usage on the environment is manifest in:

• Air pollution from transit systems, transport of necessities, automobiles, and power stations has made cities hazardous to our health, especially to children

• Acid rain created when nitric oxides and sulfur oxides combine with water in clouds

• Global warming caused by the greenhouse effect

• National security can be affected if supply is iterupted due to a political crisis

Because of the competitive nature of the global market, availability of energy supplies is unpredictable. Figure 1.1 shows the pollution as a result of burning fossil fuel.

Figure 1.1 Pollution from the fossil fuel economy.

Atmospheric concentrations of carbon dioxide and CH₄ have increased by 31% and 149%, respectively, above preindustrial levels since 1750. Globally, the majority of anthropogenic greenhouse gas emissions arise from fuel combustion. Around 17% of emissions are accounted for by the combustion of fuel for the generation of electricity using the conventional electric power plants, especially the thermal power stations.

1.2 US and world energy usage for electricity generation

Figure 1.2 shows the percentage of electricity generated by fuel type in the United States. Out of the 3883 billion Kwhs generated, coal was the primary fuel type (~ 50%) used. The figure also shows that hydroelectric systems produce about 6.5% and nuclear stations produce about 19.3%, while use of renewale energy produces about 2.3%. The total energy available is close to 4055 billion Kwh.

Figure 1.2 US electricity generation by fuel type as of 2005.

By comparing the electricity generation data (see Figure 1.2) to the projected electricity generation in 2030 (Figure 1.3), you get a good idea of the trends we will see over the next 20 years. Overall electricity generation will increase due to our expanding economy and population growth. This expansion will increase dependence on fossil fuels since the contributions from nuclear and renewable power sources remains relatively flat. Hydroelectric power also contributes to this because it remains stagnant, as can seen in Figure 1.4. It is also clear that the share of renewable energy is on the rise and that the percentage of petroleum is not expected to increase due to the expected rise of oil prices. The share of coil will increase.

Figure 1.3 Electricity generation by fuel for 2005 and 2030 (billion Kwh).

Figure 1.4 Renewable energy electricity generation, 2005 to 2030 (in billions of Kwhs).

If you then take a closer look at the electricity generated by nonhydroelectric renewable sources (Figure 1.5), you can see the future outlook of the technologies that currently exist. Solar power is not heavily used today, but it should see some growth over the next 20 years. Wind and biomass should show the most growth, while geothermal, municipal solid waste (MSW), and acronimous (LSW) will grow over the next few years and then level out.

Figure 1.5 Nonhydroelectric renewable electricity generation (in billions of Kwhs).

The previous figures focused primarily on the US generation of electricity. Figure 1.6 shows the world’s electricity generation by fuel type; it tracks the US figures fairly well. The use of fossil fuels (i.e., oil, natural gas, coal) continues to grow faster than renewable and nuclear power sources.

Figure 1.6 World electricity generation by fuel type, 2004 to 2030 (in billions of Kwhs).

1.3 Factors affecting the application and use of alternative energy sources

1.3.1 The impact of high oil prices

Fifty years ago, the United States was self-sufficient in its supply of petroleum. Today, it imports more than half of its petroleum and consumes 25% of the world’s supply. Until the mid-1950s, coal was the world's foremost fuel, but oil quickly took over. Following the 1973 and 1979 energy crises, there was significant media coverage of oil supply levels. This brought to light the concern that oil is a limited resource that will eventually run out, at least as an economically viable energy source.

Some would argue that because the total amount of petroleum is finite, the dire predictions of the 1970s have merely been postponed. Others argue that technology will continue to allow for the production of cheap hydrocarbons and that the Earth has vast sources of unconventional petroleum reserves in the form of tar sands, bitumen fields, and oil shale that will allow for petroleum use to continue in the future. For example, Canadian tar sands and US shale oil deposits represent potential r...