What is Water and Energy?
Water
Water is the most common liquid on Earth. It covers about 71.4% of the Earth. Pure water has no smell, taste, or color. Lakes, oceans, and rivers are made of water. Rain is water that falls from clouds in the sky. If water gets very cold, it freezes and becomes ice. Frozen rain can be ice or snow if conditions permit. If water gets very hot, it boils and becomes steam. Water is very important for life. However, some studies suggest that by 2025 more than half of the people around the world will not have enough water.
Water is the only substance on earth that exists naturally in three states known as solid, liquid and gas. When water freezes, its volume expands by about 9%. This expansion can cause pipes to break if the water inside them freezes.
Understanding Water and Energy Principles
To properly answer the first question above, I have decided to take a step back and look at the ‘science’ of water and energy first, so that we can better understand the ways in which they are formed and interact, and their importance to life on the planet-animals, plants and mankind - in the past, present and the future.
I have also tried to explain how water and energy are critical to the ecology of all of life on the planet and how we need to better manage both of these precious resources to sustain this life.
1. Understanding Water?
What is water? (Chemistry of)
The formula H20 tells us that one molecule of water is consisted of 2 atoms of hydrogen and one atom of oxygen bounded together. The bonds which hold the hydrogen and oxygen together are called covalent bonds - they are very strong.
Let's look at a picture of a molecule of water: In this picture the two hydrogens are represented by white spheres and the oxygen by a red sphere.
Water is the only substance on earth that exists naturally in three states known as solid, liquid and gas. When water freezes, its volume expands by about 9%. This expansion can cause pipes to break if the water inside them freezes.
Understanding Water and Energy Principles
To properly answer the first question above, I have decided to take a step back and look at the ‘science’ of water and energy first, so that we can better understand the ways in which they are formed and interact, and their importance to life on the planet-animals, plants and mankind - in the past, present and the future.
I have also tried to explain how water and energy are critical to the ecology of all of life on the planet and how we need to better manage both of these precious resources to sustain this life.
1. Understanding Water?
What is water? (Chemistry of)
The formula H20 tells us that one molecule of water is consisted of 2 atoms of hydrogen and one atom of oxygen bounded together. The bonds which hold the hydrogen and oxygen together are called covalent bonds - they are very strong.
Let's look at a picture of a molecule of water: In this picture the two hydrogens are represented by white spheres and the oxygen by a red sphere.
Indeed! Water is one of our most plentiful chemicals. Its chemical formula, H20, is probably the most well - known of all chemical formulas.
What does the chemical formula tell us?
Water Facts
We live on a water planet. However most of it is covered in salt water, covering about 71% of the earth's surface. The biotic world is also made up mostly of water, 60% of tree's weight is water, in animals including humans the figure is about 50-65 per cent water. In terms of human use, only a small fraction is available for our use.
Oceans contain 97% by volume, which is too salty for drinking, irrigation or industrial use. The 3 per cent of earth's total water is considered fresh water. About 2.997 per cent of this fresh water is trapped in polar ice caps and deep within earth's surface which is too costly to extract.
Thus only 0.003% of earth's total available water by volume is available for human use. If the world’s water was contained in 100 litres or 26 gallons, then what is readily available to us would amount to one-half teaspoon.
What does the chemical formula tell us?
Water Facts
We live on a water planet. However most of it is covered in salt water, covering about 71% of the earth's surface. The biotic world is also made up mostly of water, 60% of tree's weight is water, in animals including humans the figure is about 50-65 per cent water. In terms of human use, only a small fraction is available for our use.
Oceans contain 97% by volume, which is too salty for drinking, irrigation or industrial use. The 3 per cent of earth's total water is considered fresh water. About 2.997 per cent of this fresh water is trapped in polar ice caps and deep within earth's surface which is too costly to extract.
Thus only 0.003% of earth's total available water by volume is available for human use. If the world’s water was contained in 100 litres or 26 gallons, then what is readily available to us would amount to one-half teaspoon.
100 litres – the total amount of the world’s water. ½ teaspoon is the relative amount of water available for human use.
Water may be a substance so common that we scarcely make note of it - We waste it, pollute it, let it run down the drain, flush it away. We take it for granted!
However, chemically speaking, water is really not common at all. When compared to other compounds of similar size, composition, and structure - it is absolutely unique! In fact its properties are so unusual that it would be irreplaceable.
Water plays an important role as a chemical substance. Its many important functions include being a good solvent for dissolving many solids, serving as an excellent coolant both mechanically and biologically, and acting as a reactant in many chemical reactions. Blood, sweat and tears... all solutions of water.
Where Does Water Come From?
The Origin of Water - The Big Bang
Approximately 10 to 20 billion years ago, the Universe was in an extremely dense and hot (10 billion °C !) state that exploded in what astronomers call The Big Bang.
Eventually, the Universe expanded and cooled and huge collections of gas formed into billions of separate galaxies, and billions of stars formed within each. Many fundamental particles were formed in the beginning of this process, including the basic building blocks of all atoms: protons, neutrons, and electrons.
The two lightest elements, hydrogen and helium, were also formed. Hydrogen consists of one proton with one electron circling it. Helium consists of two protons and two electrons.
Now, given the creation of hydrogen in the Big Bang and oxygen in nucleo - synthesis in stars, and the fact that these elements are highly reactive chemically, water should therefore be fairly common in the Universe. However, only at certain temperatures and pressure, like those we find on Earth, would we expect to find liquid water.
However, chemically speaking, water is really not common at all. When compared to other compounds of similar size, composition, and structure - it is absolutely unique! In fact its properties are so unusual that it would be irreplaceable.
Water plays an important role as a chemical substance. Its many important functions include being a good solvent for dissolving many solids, serving as an excellent coolant both mechanically and biologically, and acting as a reactant in many chemical reactions. Blood, sweat and tears... all solutions of water.
Where Does Water Come From?
The Origin of Water - The Big Bang
Approximately 10 to 20 billion years ago, the Universe was in an extremely dense and hot (10 billion °C !) state that exploded in what astronomers call The Big Bang.
Eventually, the Universe expanded and cooled and huge collections of gas formed into billions of separate galaxies, and billions of stars formed within each. Many fundamental particles were formed in the beginning of this process, including the basic building blocks of all atoms: protons, neutrons, and electrons.
The two lightest elements, hydrogen and helium, were also formed. Hydrogen consists of one proton with one electron circling it. Helium consists of two protons and two electrons.
Now, given the creation of hydrogen in the Big Bang and oxygen in nucleo - synthesis in stars, and the fact that these elements are highly reactive chemically, water should therefore be fairly common in the Universe. However, only at certain temperatures and pressure, like those we find on Earth, would we expect to find liquid water.
Water Physics
The chemical building blocks of water, hydrogen and oxygen, were formed in the "big bang" and in the interior of stars by a process known as nuclear synthesis.
The earth appears to be unique in our solar system in that it contains an enormous amount of water, and that water has existed in a form not too different from its present state for billions of years.
Given that the laws of nature operate everywhere in the solar system, we have to question why we are so privileged to have large bodies of liquid water on our planetary surface for so long a time.
The formation of the earth probably took a few hundred million years to be completed. That is to be compared with the time of about 3.5 billion years since the earth has developed a solid crust.
Over a relatively short time, something like a 100 million years, enough material had been released to form the oceans and to give the earth an atmosphere. Fortunately, early in its history, the temperature of the earth dropped below 212 degrees Fahrenheit, and the water condensed into the oceans we know today.
Water Loss
We can estimate the rate at which water is being lost today by estimating the rate at which water molecules in the atmosphere are dissociated into its constituent hydrogen and oxygen.
The hydrogen is light enough that it easily moves off into space. The net effect of hydrogen loss decreases the amount of water vapour in the atmosphere.
A good estimate is that 5x10(11) grams are lost this way each year. This amounts to a volume of a cube about 100 yards on a side. The total water lost to space since the beginning of the earth thus amounts to about 2x10(21) grams, about 0.2 percent of the water in the oceans.
This means that most of the water you see on the earth was the very same stuff that was originally formed from the Earth’s crust when the earth was only a few hundred million years old.
Water Gain
Fortunately, the water lost to space is replaced by the same geologic processes that formed the oceans originally.
At the present time, about 70% of the surface of the earth is covered with water. The present coastlines are where they are because some of the water is locked up in the polar ice caps.
Where is the water on Earth today?
In terms of volume, the water on earth is distributed in the following way:
Conclusion: Water is a very precious substance and needs to be looked after in the future.
The earth appears to be unique in our solar system in that it contains an enormous amount of water, and that water has existed in a form not too different from its present state for billions of years.
Given that the laws of nature operate everywhere in the solar system, we have to question why we are so privileged to have large bodies of liquid water on our planetary surface for so long a time.
The formation of the earth probably took a few hundred million years to be completed. That is to be compared with the time of about 3.5 billion years since the earth has developed a solid crust.
Over a relatively short time, something like a 100 million years, enough material had been released to form the oceans and to give the earth an atmosphere. Fortunately, early in its history, the temperature of the earth dropped below 212 degrees Fahrenheit, and the water condensed into the oceans we know today.
Water Loss
We can estimate the rate at which water is being lost today by estimating the rate at which water molecules in the atmosphere are dissociated into its constituent hydrogen and oxygen.
The hydrogen is light enough that it easily moves off into space. The net effect of hydrogen loss decreases the amount of water vapour in the atmosphere.
A good estimate is that 5x10(11) grams are lost this way each year. This amounts to a volume of a cube about 100 yards on a side. The total water lost to space since the beginning of the earth thus amounts to about 2x10(21) grams, about 0.2 percent of the water in the oceans.
This means that most of the water you see on the earth was the very same stuff that was originally formed from the Earth’s crust when the earth was only a few hundred million years old.
Water Gain
Fortunately, the water lost to space is replaced by the same geologic processes that formed the oceans originally.
At the present time, about 70% of the surface of the earth is covered with water. The present coastlines are where they are because some of the water is locked up in the polar ice caps.
Where is the water on Earth today?
In terms of volume, the water on earth is distributed in the following way:
- 1.35 x10(17) cubic meters (97.3%) Oceans
- 29x10(15) cubic meters (2.1%) polar ice and glaciers
- 8.4x10(15) cubic meters (0.6 %) underground aquifers (fresh)
- 0.2x10(15) cubic meters (0.01%) lakes and rivers
- 0.013x10(15) cubic meters (0.001%) atmosphere (water vapour)
- 0.0006x10(15) cubic meters (0.00004%) biosphere.
Conclusion: Water is a very precious substance and needs to be looked after in the future.
2. Energy
Energy lights our cities, powers our vehicles, and runs machinery in factories. It warms and cools our homes, cooks our food, plays our music, and gives us pictures on television. Energy is defined as the ability or the capacity to do work.
We use energy to do work and make all movements. When we eat, our bodies transform the food into energy to do work. When we run or walk or do some work, we burn energy in our bodies. Cars, planes, trolleys, boats, machinery etc also transform energy into work. Work means moving or lifting something, warming or lighting something. There are many sources of energy that help to run the various machines invented by man.
Understanding Energy
The Basic Laws of Energy. (The 3 laws of thermo dynamics)
1. The first law of thermodynamics, also called conservation of energy, states that the total amount of energy in the universe is constant.
This means that all of the energy has to end up somewhere, either in the original form or in a different from. We can use this knowledge to determine the amount of energy in a system, the amount lost as waste heat, and the efficiency of the system.
2. The second law of thermodynamics states that the disorder in the universe always increases. After cleaning your room, it always has a tendency to become messy again.
This is a result of the second law. As the disorder in the universe increases, the energy is transformed into less usable forms. Thus, the efficiency of any process will always be less than 100%.
3. The third law of thermodynamics tells us that all molecular movement stops at a temperature we call absolute zero, or 0 Kelvin (-273 degrees C).
When put together, these laws state that a concentrated energy supply must be used to accomplish useful work.
1. Work
Many of us commonly think of energy as the ability of a system to do work. Work is a force applied to an object over a certain distance, such as pulling or pushing a wooden block across your desk. Units of work and energy are joules (J). One joule equals one Newton meter (Nm).
By definition, work is an energy requiring process. So, how do you describe energy? Energy is not a substance that can be held, seen, or felt as a separate being.
We cannot create new energy that is not already present in the universe. We can only take different types of materials in which energy is stored, change their state, and harness the energy that escapes from the system in order to use it to do work for us.
If the released energy is not used, it will escape and be "wasted" usually as heat. The “Big Three” of engines - gasoline, diesel, and steam turbine have carried economies from the industrial revolution to the modern era. All three are heat engines - they transform heat, or thermal energy to mechanical energy.
In the other direction, mechanical energy can be abandoned or cheapened to heat, as with brakes on an automobile. All forms of energy - even light, sound, and the biochemical energy in food - are ultimately abandoned as heat.
2. Work and Power
Lifting 200 pounds two feet is a challenge for most of us. On the other hand, almost anyone can pull a rope with 40 pounds (#) of resistance for 10 feet. Yet, from the view-point of production, both accomplish equal amounts of gravitational work, 400 foot-pounds: 200 lbs x 2 ft = 400 ft-lbs or 40 lbs x 10 ft = 400 ft-lbs.
3. Thermal Energy
One measure of heat energy is the BTU (British Thermal Unit). A BTU is the energy that goes into heating one pound of water one degree Fahrenheit. Amazingly, this is the equivalent of 778 ft-lbs of work. In other words, the thermal energy that goes into raising the temperature of an 11 ounce mug of coffee one degree (°F) is approximately equivalent to the work of lifting 55 pounds up one flight of stairs. (A pint, or 16 fluid ounces of water weighs about one pound. Rule of thumb -- A pint’s a pound the world around.)
You can see the mechanical equivalent of thermal energy on the figure bellow:
We use energy to do work and make all movements. When we eat, our bodies transform the food into energy to do work. When we run or walk or do some work, we burn energy in our bodies. Cars, planes, trolleys, boats, machinery etc also transform energy into work. Work means moving or lifting something, warming or lighting something. There are many sources of energy that help to run the various machines invented by man.
Understanding Energy
- What Is Energy?
We can think of energy as anything that can carry out an action or maintain a process. Without energy, everything comes to a halt. Though energy is not as touchable as mass, distance or force, its effects are just as real.
**Energy is the capacity to do work or to transfer heat**
Work is the product of force and distance. For example, a force of 40 pounds moving 15 feet represents 600 ft-lbs of energy. This mechanical aspect of energy is shown in many activities. Think of the motion of an automobile, a cheetah, or a rocket. Basic Energy Principles - Energy is the driving force for the universe.
- Energy is a quantitative property of a system which may be kinetic, potential, or other in form.
- There are many different forms of energy.
- One form of energy can be transferred to another form.
- The laws of thermodynamics govern how and why energy is transferred.
The Basic Laws of Energy. (The 3 laws of thermo dynamics)
1. The first law of thermodynamics, also called conservation of energy, states that the total amount of energy in the universe is constant.
This means that all of the energy has to end up somewhere, either in the original form or in a different from. We can use this knowledge to determine the amount of energy in a system, the amount lost as waste heat, and the efficiency of the system.
2. The second law of thermodynamics states that the disorder in the universe always increases. After cleaning your room, it always has a tendency to become messy again.
This is a result of the second law. As the disorder in the universe increases, the energy is transformed into less usable forms. Thus, the efficiency of any process will always be less than 100%.
3. The third law of thermodynamics tells us that all molecular movement stops at a temperature we call absolute zero, or 0 Kelvin (-273 degrees C).
When put together, these laws state that a concentrated energy supply must be used to accomplish useful work.
1. Work
Many of us commonly think of energy as the ability of a system to do work. Work is a force applied to an object over a certain distance, such as pulling or pushing a wooden block across your desk. Units of work and energy are joules (J). One joule equals one Newton meter (Nm).
By definition, work is an energy requiring process. So, how do you describe energy? Energy is not a substance that can be held, seen, or felt as a separate being.
We cannot create new energy that is not already present in the universe. We can only take different types of materials in which energy is stored, change their state, and harness the energy that escapes from the system in order to use it to do work for us.
If the released energy is not used, it will escape and be "wasted" usually as heat. The “Big Three” of engines - gasoline, diesel, and steam turbine have carried economies from the industrial revolution to the modern era. All three are heat engines - they transform heat, or thermal energy to mechanical energy.
In the other direction, mechanical energy can be abandoned or cheapened to heat, as with brakes on an automobile. All forms of energy - even light, sound, and the biochemical energy in food - are ultimately abandoned as heat.
2. Work and Power
Lifting 200 pounds two feet is a challenge for most of us. On the other hand, almost anyone can pull a rope with 40 pounds (#) of resistance for 10 feet. Yet, from the view-point of production, both accomplish equal amounts of gravitational work, 400 foot-pounds: 200 lbs x 2 ft = 400 ft-lbs or 40 lbs x 10 ft = 400 ft-lbs.
3. Thermal Energy
One measure of heat energy is the BTU (British Thermal Unit). A BTU is the energy that goes into heating one pound of water one degree Fahrenheit. Amazingly, this is the equivalent of 778 ft-lbs of work. In other words, the thermal energy that goes into raising the temperature of an 11 ounce mug of coffee one degree (°F) is approximately equivalent to the work of lifting 55 pounds up one flight of stairs. (A pint, or 16 fluid ounces of water weighs about one pound. Rule of thumb -- A pint’s a pound the world around.)
You can see the mechanical equivalent of thermal energy on the figure bellow:
There are a seemingly endless number of energy units and their conversions, with contributions from the English and French systems, as well as heat and mechanics. The BTU and ft-lb, for example, are from the English system.
4. Conservation of Energy
Here is a basic principle of physics, known as the First Law of Thermodynamics -- energy can neither be created nor destroyed, it can only be transformed.
In a closed system or tank, the energy remains constant. If the energy at the start is Q0, then it remains at Q0. In an open system, if the storage does not change, the ingoing and outgoing energy must be equal. If the storage changes, this must be reflected in the energy balance.
Energy conservation law:
The energy input to a system might not balance the energy that goes out.
5. Entropy and the Degradation of Energy
In any transformation of energy some becomes unavailable. Entropy is a measure of its unavailability. This loss of usable energy is due to many causes:
Anything that tends to degrade, disorder, or destruct a system will increase the entropy of the system. The above examples and terminology draw attention to physical systems.
6. Efficiency
The (thermodynamic) efficiency of a process is inversely related to the entropy. This is the ratio of useful output to input and so is always less than 100%.
Calculating energy efficiency:
Industrial economies are built on heat engines, and much effort goes into improving their efficiencies.
The Big Three of heat engines are the Diesel (oil), gasoline, and steam engines.
The distance measured in miles of cars is a good, practical measure of the efficiency of engines used for transportation. The increase in miles per gallon - mpg, for gasoline engines has been significant over the past ten years. Sometimes it is charged that oil companies but an end to engine designs that will get 300+ mpg.
The charges are based on calculations that convert almost all the energy of gasoline into useful work. Unfortunately, “the iron law of entropy” will exact its tax by sucking much of the energy into the heat sink. Can engineers improve the design of a gasoline engine so that it is almost 100% efficient? The answer, unfortunately, is No. The thermodynamic efficiency of internal combustion engines is 50-55%, and this is a maximum. Actual efficiency is always less, running about 35% for current automobile engines.
7. Kinetic and Potential Energy
Physicists divide energy into two classes, kinetic or moving energy, and potential or stored energy.
The kinetic energy (KE) of an object or system is the energy it has by goodness of its motion.
The potential energy (PE) of an object or system is the energy possessed by goodness of its position or structure. For example, a stretched bow, upon release, transforms its PE to the KE of the arrow in flight, water as a cloud possesses gravitational PE; water in the form of falling rain possesses KE. The KE in glucose (a sugar) can be transformed into the KE of muscular action.
4. Conservation of Energy
Here is a basic principle of physics, known as the First Law of Thermodynamics -- energy can neither be created nor destroyed, it can only be transformed.
In a closed system or tank, the energy remains constant. If the energy at the start is Q0, then it remains at Q0. In an open system, if the storage does not change, the ingoing and outgoing energy must be equal. If the storage changes, this must be reflected in the energy balance.
Energy conservation law:
The energy input to a system might not balance the energy that goes out.
5. Entropy and the Degradation of Energy
In any transformation of energy some becomes unavailable. Entropy is a measure of its unavailability. This loss of usable energy is due to many causes:
- In mechanical systems it is friction
- In electrical systems it is resistance
- In fluid systems it is turbulence, viscosity or mixing
- In communication systems it is noise
- In an agency it is disorganisation
Anything that tends to degrade, disorder, or destruct a system will increase the entropy of the system. The above examples and terminology draw attention to physical systems.
6. Efficiency
The (thermodynamic) efficiency of a process is inversely related to the entropy. This is the ratio of useful output to input and so is always less than 100%.
Calculating energy efficiency:
Industrial economies are built on heat engines, and much effort goes into improving their efficiencies.
The Big Three of heat engines are the Diesel (oil), gasoline, and steam engines.
The distance measured in miles of cars is a good, practical measure of the efficiency of engines used for transportation. The increase in miles per gallon - mpg, for gasoline engines has been significant over the past ten years. Sometimes it is charged that oil companies but an end to engine designs that will get 300+ mpg.
The charges are based on calculations that convert almost all the energy of gasoline into useful work. Unfortunately, “the iron law of entropy” will exact its tax by sucking much of the energy into the heat sink. Can engineers improve the design of a gasoline engine so that it is almost 100% efficient? The answer, unfortunately, is No. The thermodynamic efficiency of internal combustion engines is 50-55%, and this is a maximum. Actual efficiency is always less, running about 35% for current automobile engines.
7. Kinetic and Potential Energy
Physicists divide energy into two classes, kinetic or moving energy, and potential or stored energy.
The kinetic energy (KE) of an object or system is the energy it has by goodness of its motion.
The potential energy (PE) of an object or system is the energy possessed by goodness of its position or structure. For example, a stretched bow, upon release, transforms its PE to the KE of the arrow in flight, water as a cloud possesses gravitational PE; water in the form of falling rain possesses KE. The KE in glucose (a sugar) can be transformed into the KE of muscular action.