Ocean Energy Modeling and Simulation with Big Data: Computational Intelligence for System Optimization and Grid Integration

By Vikas Khare, Savita Nema and Prashant Baredar

Ocean Energy Modeling and Simulation with Big Data: Computational Intelligence for System Optimization and Grid Integration offers the fundamental and practical aspects of big data solutions applied to ocean and offshore energy systems. The book explores techniques for assessment of tidal, wave and offshore wind energy systems. It presents the use of data mining software to simulate systems and Hadoop technology to evaluate control systems. The use of Map Reduce algorithms in systems optimization is examined, along with the application of NoSQL in systems management. Actual data collection through web-based applications and social networks is discussed, along with practical applications of recommendations.

• Introduces computational methods for processing and analyzing data to predict ocean energy system production, assess their efficiency, and ensure their reliable connection to power grids
• Covers data processing solutions like Hadoop, NoSQL, Map Reduce and Lambda, discussing their applications in ocean energy for system design and optimization
• Provides practical exercises that demonstrate the concepts explored in each chapter

• Language: English
• Publisher: Elsevier Science
• Release date: Apr 21, 2020
• ISBN: 9780128189054

Vikas Khare

Vikas Khare is an associate professor at the School of Technology, Management and Engineering, NMIMS, Indore Madhya Pradesh, India. He obtained his B.Tech in Electrical Engineering in 2007 from GEC Sagar, M.Tech (Honors) in Energy Management from DAVV Indore in 2011, and Ph.D. from National Institute of Technology Bhopal, India in 2016, with teaching experience of 12 years. His main research interests are renewable energy systems, optimization techniques and game theory and Big Data. He is also a certified energy manager under the bureau of energy efficiency in India. Dr. Khare has published various research papers in reputed journals such as Elsevier and Taylor and Francis and published books on Renewable Energy in Balaji Publication Fundamentals of Electrical Engineering, Fundamentals of Electrical & Electronics Engineering, Fundamentals of Electronics Engineering in Dhanpat Rai Publication and one book of Tidal energy system, Elsevier publication USA. He is also Nominee member of computer society of India.

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FAMILY

Preface

Dear Student,

I am very happy to present the book Ocean Energy Modeling and Simulation With Big Data for you. I have divided the subject into small chapters for the convenience of the students, and so that the topics can be arranged and understood properly. The topics within the chapters have been arranged in the proper sequence to ensure the smooth flow of the subject.

A large number of solved examples have been included. We are sure that this book will cater for all your needs regarding this subject.

We are thankful to Dr. Prachi Gharpure, Director NMIMS, Indore and Dr. Aaquil Bunglowala, Associate Dean STME, NMIMS, Indore for the encouragement and support that they have extended. We are also thankful to the staff members of Elsevier Publications and others for their efforts to make this book as good as it is. We have jointly made every possible effort to eliminate any errors in this book. However if you find any, please let us know, because that will help us to improve further.

We are also thankful to our family members and friends for their patience and encouragement. I want to give special thanks to my wife Dr. Cheshta Khare who provided so much guidance to enable the completion of this book.

Thanking you

Vikas Khare, Savita Nema, Prashant Baredar

Chapter 1

Fundamental and principles of the ocean energy system

Abstract

The capability of creating power from ocean streams is colossal. The energy of the ocean is an inexhaustible source that has an advantage in a future energy showcase compared to other sustainable power sources due to its high reliability. Additionally, ocean energy innovations can provide CO2 emission-free power, and empower energy security and add to economic development and the creation of employment in beachfront and remote areas. This chapter includes the principles and types of ocean energy systems and also describes separately the basic principles of tidal energy, wave energy, and offshore wind energy systems. Finally, this chapter also discusses the worldwide and Indian scenarios for ocean energy systems.

Keywords

Tidal energy; wave energy; offshore wave energy

Objectives

• To provide knowledge about energy systems.

• To provide knowledge about ocean energy systems.

• To provide knowledge about tidal energy systems.

• To provide knowledge about wave energy systems.

• To provide knowledge about offshore wind energy systems.

• To provide knowledge about the scenarios of ocean energy systems.

1.1 Introduction

In physics and the field of engineering, energy is a versatile property of a existing system that cannot be directly effect but can be evaluated from one circumstance to another with certain performance parameters. Energy plays an important role in any physical system and in different engineering applications, but it is difficult to give a definition of energy in a broad way because one form of energy can be converted into other different forms of energy. However, the most frequent definition is that it is the capability of a system to perform the desired work. A running person is said to be more energetic compared to a sleeping person. In physics a moving particle is said to have more energy than an identical particle at rest. The characterization of work in engineering physics is the action of a force throughout a distance and energy is dissipated through the workdone. If any human being pushes an entity "n meters against a conflicting force of f" newton, fn joules (newton-meters) of work has been done on the given entity; the person’s body has lost fn joules of energy and the entity has gained Fx joules of energy. The SI unit of energy is given by the joule (J) (the equivalent to a newton-meter or a watt-second), the CGS unit is the erg, and the Imperial unit is the foot-pound. Other energy units, such as the electron volt, calorie, BTU, and kilowatt hour (1 kWh¼3600 kJ), are used in specific areas of science and engineering. Energy is hugely significant in engineering due to the law of conservation of energy, which states that energy can neither be created nor destroyed but can be changed from one form to another form. For example, in a mixer grinder, electrical energy is converted into mechanical and sound energy. A hair dryer is one of the best examples that shows how one form of energy is converted into a different form of energy. That is because in a hair dryer electrical energy is converted into mechanical energy, thermal energy, and sound energy. Both examples show the phenomenon of energy transformation because energy transformation is the change of energy from one form to another.

Energy transformation occurs everywhere, every second of the day. Energy is converted from one form to another form, for example, in fuel cells chemical energy is converted into useful electric energy. For electricity generation through hydro energy, first the gravitational potential energy is converted into kinetic energy and then the kinetic energy is converted into useful electric energy through a DC or AC generator. Carnot’s theorem and the second law of thermodynamics present some difficulties regarding when energy can be transformed into other forms of energy by work and heat. Energy is a scalar as well as a vector quantity because the direction of conversion and transformation of energy is elaborated by entropy considerations. Most energy transformations are done at a small scale, but certain larger transformations, such as the transformation of electrical energy, are possible with the help of additional equipment. The transformation of energy into constructive work is an innermost and primary part of thermodynamics. At the primary level, the transformation of energy is done in two ways: reversible thermodynamics and irreversible thermodynamics.

In the mechanical-to-electrical analogy, thermodynamically reversible is related to renewable energy sources and thermodynamically irreversible is related to nonrenewable energy sources. In this case, the energy must partially continue as heat and cannot be entirely recovered as a useful form of energy. Electrical energy is the most important form of energy because it is used to generate electricity and in daily life lot of work is done through electrical energy. The generation of electrical energy has been always categorized into two parts: conventional and nonconventional energy. In conventional electricity generation, electrical energy is generated through thermal, steam, and nuclear power plants, but such types of power plants produce lots of pollution that can lead to lots of diseases that are harmful to humans. To compensate for such problems, nowadays electricity is being generated increasingly through nonconventional or renewable energy sources. Electricity generated through solar energy systems, wind energy systems, biomass energy systems, and ocean energy systems is the result of a renewable energy system. This book has its main emphasis on ocean energy systems and assessment of the ocean energy system is done through big data assessment. Chapter 2, Big data principles and paradigm, will explain all the necessary concepts of big data and also explain the application of big data in the field of the ocean energy system.

1.2 Principles of the ocean energy system

Due to industrialization the world has come to the point where it needs more energy than ever before as energy demand grows rapidly globally. But not only does the world need energy, it also needs energy gained from renewable and ecologically acceptable fuels that does not cause major ecological problems, such as global warming and air pollution. Ocean energy could well be one of these new renewable energy sources and should really play a more significant role in the upcoming years. Oceans cover 70% of the Earth’s surface and represent an enormous amount of energy in the form of wave, tidal, marine current, and thermal resources. Although ocean energy is still in a developmental stage, researchers are seeking ways to capture that energy and convert it to electricity. Ocean energy and marine energy refer to various forms of renewable electric energy harnessed from the ocean. There are two primary types of ocean energy: mechanical and thermal. The basic principle of the ocean energy system depends on the rotation of the Earth and the Moon’s gravitational pull creating mechanical forces. The rotation of the Earth creates wind that forms waves on the ocean surface, while the gravitational pull of the Moon creates coastal tides and currents. Fig. 1.1 shows the basic principle of the ocean energy system, in which the rotation of the Earth and the orbit of the Moon are the primary steps for the generation of wave and tidal energy, respectively.

Figure 1.1 Principles of the ocean energy system.

Thermal energy is also derived from the Sun, which heats the surface of the ocean while the depths remain colder. In the ocean energy system, this temperature difference allows energy to be captured and converted to electric power, which is a form of a renewable energy system. Ocean thermal energy conversion (OTEC) requires a temperature difference of at least 20°C. In tropical and subtropical latitudes between 24 degrees north and 24 degrees south of the equator, ocean water varies by 20°C from the surface to depths of 1000 m. The estimated potential power of the thermal energy resource worldwide is 10,000 TWh/year.

1.3 Types of ocean energy system

In the present scenario the ocean energy system is the most promising technology for renewable energy systems. In this technology seawater levels play an important role and different energy conversion systems harness energy from seawater and convert it into electrical energy systems. There are three types of ocean energy system.

1. Tidal energy system: Tidal power or tidal energy is a form of hydropower that converts the energy obtained from tides. While tidal power will take additional energy from the system, the effect is negligible and would only be noticed over millions of years.

2. Wave energy system: Wave energy is actually a concentrated form of solar power generated by the action of the wind blowing across the surface of the ocean’s water which can then be used as a renewable source of energy. As the Sun’s rays strike the Earth’s atmosphere, they warm it up.

3. Offshore wind energy system: Offshore wind power or offshore wind energy is the use of wind farms constructed in bodies of water, usually in the ocean on the continental shelf, to harvest wind energy to generate electricity. Higher wind speeds are available offshore compared to on land, so offshore wind power’s electricity generation is higher per amount of capacity installed.

Fig. 1.2 shows the different forms of ocean energy system in terms of tides, waves, thermal gradient, and offshore wind energy systems.

Figure 1.2 Forms of ocean energy systems.

1.3.1 Estimation of the energy calculation of all types of ocean energy system

An ocean power station feeds different types of consumers: domestic, commercial, industrial, agricultural, etc. The present-day ocean power station invariably feeds a grid which delivers power to the load centers. Each device at the consumers’ terminals has its rated capacity. The connected load of a consumer means the sum of the continuous rating of all the devices and outlets installed on his distribution circuit. The maximum demand of a consumer means the maximum power that his circuit is likely to draw at any time.

Maximum demand (peak load): It is characterized as the maximum power required by the consumer over a particular time frame. It is likewise equivalent to the maximum real power produced by the plant when transmission losses are disregarded. The highest demand of every consumer is, however, not as much as his associated stack. The highest demand and the associated stack are connected by:

Average load: It is the average power that is consumed by the load during a specific period of time and it is equal to the average power that is generated by the plant during the same period of time when transmission line losses are neglected.

Load factor: It is the proportion of the normal load to the most extreme load for a specific time frame. The load factor is called the day-by-day load factor if the time frame is a day, and if the time frame is a month, the load factor is called the month-to-month stack factor, and correspondingly for the year stack factor.

Installed capacity (plant capacity, nameplate capacity): It represents the maximum possible power that could be produced (generated) by the power plant. The value of the installed capacity depends on the plant design.

Plant capacity factor: The capacity factor of a power plant is the proportion of its normal yield over a period of time, to the greatest conceivable power that could be created. The net limit factor is the unitless proportion of a genuine electrical energy yield over a given time frame to the most extreme conceivable electrical energy yield over a similar measure of time. The limiting factor is characterized for any power delivering establishment, that is, a fuel-fed plant or one utilizing a sustainable power source, for example, wind or the Sun. The normal limiting factor can likewise be characterized for any class of such establishments, and can be utilized to analyze diverse sorts of power generation. The maximum possible energy output of a given installation assumes its continuous operation at full nameplate capacity over the relevant period of time. The actual energy output over the same period of time, and with it the capacity factor, varies greatly depending on a range of factors. The capacity factor can never exceed the availability factor or the fraction of downtime during the period. Downtime can be due to, for example, reliability issues and maintenance issues, both scheduled and unscheduled. It can be determined as follows:

In electrical engineering the utilization factor is the ratio of the maximum load which could be drawn to the rated capacity of the system. This is closely related to the concept of load factor. The load factor is the ratio of the load that a piece of equipment actually draws (time-averaged) when it is in operation to the load it could draw (which we call full load).

For example, an oversized motor (15 kW) drives a constant 12 kW load whenever it is on. The motor load factor is then 12/15=80%. The motor above may only be used for 8 hours a day, 50 weeks a year. The hours of operation would then be 2800 hours, and the motor use factor for a base of 8760 h/year would be 2800/8760=31.96%. With a base of 2800 h/year, the motor use factor would be 100%.

Diversity factor: It is the ratio of the sum of the individual maximum demands of the various subdivisions of a system (or part of a system) to the maximum demand of the whole system (or part of the system) under consideration. Diversity is usually more than one.

The technology required to convert tidal range into electricity is very similar to that in conventional hydroelectric power plants, but in this case the current flows in both directions. This means that tidal barrages are unable to produce electricity at a constant rate, as they have to wait for a sufficient hydrostatic head between the two sides of the dam. However, electricity production from tidal barrages is totally predictable, allowing for ease of electricity supply.

1.4 Fundamentals of tidal energy

One type of ocean energy system is tidal energy, since when tides come up the shore, they can be trapped in reservoirs behind dams. Tidal power is actually a form of hydropower that exploits the movement of water caused by tidal currents or the rise and fall in sea levels. Tidal energy is produced thanks to the use of tidal energy generators which are large underwater turbines placed in areas with high tidal movements, and they are designed to capture the kinetic motion of the ebbing and surging of ocean tides in order to produce electricity. Tidal power has enormous potential for future electricity generation because of the massive size of the oceans. The potential of tidal power has been recognized for a very long time, however, compared to river dams, tidal power projects are much more expensive, since massive structures must be built in a difficult saltwater environment. Cost-effectiveness is actually a main reason why tidal power has not yet found its place among the most used renewable energy sources despite its huge potential. Tidal power, in order to function at a sufficient level, needs very large increases in tides, of at least 16 ft between low tide and high tide. There are not many areas on Earth that meet these demands. However, one of these areas is La Rance Station in France, the largest tidal power station in the world (also the only one in Europe). It is in the Rance estuary in northern France and provides enough energy to satisfy the demands of 240,000 homes. The capacity of this tidal power plant is approximately one-fifth of a regular nuclear or coal-powered plant. The main problem of all tidal power plants is the fact that they can only generate when the tide is flowing in or out which counts for only 10 h/day. However, there is also the advantage that tides are totally predictable, so we can plan to have other power stations generating at those times when the tidal station is out of action, which is something that cannot be done with certain other renewable energy resources (e.g., wind energy).

Tidal energy has many advantages (it is a renewable energy source since tides will continue to ebb and flow and it produces no greenhouse gases or any waste; it needs no fuel in order to work, since tides are totally predictable; it can produce electricity reliably; and once built it is not expensive to maintain), but there are also some negative sides as well. Cost-effectiveness is still a very serious issue since building one of these power plants requires a very large area and this also brings some environmental problems since it completely changes the environment in this area, affecting the life of many ecosystems, especially for birds that forage on the mudflats uncovered as the tide goes out. There is also the already mentioned fact of the limited working time of only about 10 hours when the tide is actually moving.

1.4.1 Generation of tides

Tidal power or tidal energy is a type of hydropower that converts the energy acquired from tides into valuable types of energy, principally power. In spite of the fact that generally it has not yet been utilized, tidal energy has potential for future power. Tides are more consistent than the breeze and the Sun. The tide is the constant rise and fall of water level of the ocean. Tides happen because of the attraction of the ocean’s water by the Moon. At the point when the water is over the mean ocean level it is called the surge tide. At the point when the water level is beneath the mean level it is called the ebb tide. The sea tides rise and fall and water can be stored during its ascent and then it can be released the tide falls. A dam is built isolating the tidal bowl from the ocean and a distinction in water level is achieved between the bowl and ocean. At the high tide period, water streams from the ocean into the tidal bowl through the water turbine. The stature of tide is over that of tidal bowl. Subsequently the turbine unit works and produces electricity, as it is specifically coupled to a generator.

Tide changes proceed via the following stages:

• Sea level rises over several hours, covering the intertidal zone; flood tide.

• The water rises to its highest level, reaching high tide.

• Sea level falls over several hours, revealing the intertidal zone; ebb tide.

• The water stops falling, reaching low tide.

Tidal range: Tidal range is the difference in water levels between two consecutive high tides and low tides. The rise and fall of water level in the sea during tides can be represented by a sine curve. One tidal day is 24 hours and 50 minutes and there are two tidal cycles in one tidal day. The normal tide is a semidiurnal tide with a period of 12 hours and 25 minutes. Diurnal means daily, that is, the activities of the tide pattern over 24 hours. Diurnal tides indicate two high and two low tides created by the Moon during one rotation of the Earth on its axis. The daily tidal cycle follows a sinusoidal pattern.

Swaying ebbs and flows delivered by tides are known as tidal streams. The periods when the tidal flow stops are called slack water or slack tide. The tide at that point switches and is said to turn. Slack water for the most part happens close to high water and low water. Be that as it may, there are areas where the snapshots of slack tide contrast fundamentally from those of high and low water. Tides are usually semidiurnal (two high waters and two low waters every day), or diurnal (one tidal cycle for each day). The two high waters on a given day are commonly not a similar height (the everyday disparity); these are the higher high water and the lower high water in tide tables. Essentially, the two low waters every day are the higher low water and the lower low water. The everyday imbalance is not predictable and is by and large at its lowest when the Moon is over the equator. Fig. 1.3 shows a description of different types of tides from the highest to the lowest:

Highest astronomical tide (HAT): The highest tide which can be predicted to occur. Note that meteorological conditions may add extra height to the HAT.

Mean high water springs: The average of the two high tides on the days of spring tides.

Mean high water neaps: The average of the two high tides on the days of neap tides.

Mean sea level (MSL): This is the average sea level. The MSL is constant for any location over a long period.

Mean low water neaps: The average of the two low tides on the days of neap tides.

Mean low water springs: The average of the two low tides on the days of spring tides.

Lowest astronomical tide and chart datum (CD): The lowest tide which can be predicted to occur. Modern charts use this as the CD. Note that under certain meteorological conditions the water may fall lower than this, meaning that there is less water than shown on charts.

Figure 1.3 Schematic arrangement of low and high tide period.

1.4.2 Principles of tidal power stations

The basic principles of tidal power stations are as follows:

1. Barrages make use of the potential energy from the difference in height (or head) between high and low tides. Barrages suffer from the problems of very high civil infrastructure costs, few viable sites globally, and environmental