CONTENTS CHAPTER 1 A World of Energy 4 CHAPTER 2 Energy From Fossil Fuels 6 CHAPTER 3 Nuclear Energy 16 CHAPTER 4 Geothermals and Ambient Energy 22 CHAPTER 5 Bioenergy and Recycled Energy 28 CHAPTER 6 Solar Energy 36 CHAPTER 7 Wind Energy 44 CHAPTER 8 Water Energy 50 CHAPTER 9 Future Energy Sources 56 Glossary 60 Further Information 63 Index 64
CHAPTER 1 A World of Energy Everything on Earth depends on energy to survive Humans need energy from food to stay alive We also use various forms of energy to warm or cool ourselves and to move around Virtually all of the energy used on Earth comes from the Sun Plants use energy from the Sun to grow for example Even the gas we put in our cars can be traced back to the Sun because it is made from the fossilized remains of plants and animals that lived millions of years ago Those ancient plants and animals depended on the Sun for energy and when they died some of that energy was captured and stored in their remains Everlasting Energy In scientific terms energy is the ability to do work Energy cannot be created or destroyed It can be transformed from one form to another but the total amount of energy in the universe is always the same For example a photovoltaic cell in a solar panel converts radiant energy from the Sun into electrical energy Your 4 Forms of Energy The re a re man y d i f fe ren t fo rm s o f ene rg y bu t they are catagorized into two main groups k i n e t i c e n e r g y a n d p o t e n t i a l e n e r g y Kinetic energy is the energy of motion Here are some examples Radiant energyis electromagnetic energy that travels in waves It includes visible light X-rays and radio waves Solar energy from the Sun is an e x a m p l e o f r a d i a n t e n e r g y Thermal energyis the internal energy in a substance created by the vibration or movement of molecules Geothermal energy comes from heat beneath Earth’s surface Motion energyis the movement of objects f r o m o n e p l a c e t o a n o t h e r W i n d i s a n e x a m p l e o f m o t i o n e n e r g y P o t e n t i a l e n e r g y i s s t o r e d e n e r g y H e r e a r e some examples Chemical energyis the energy stored in the bonds between atoms The energy stored in oil coal or biomass such as plants is an example Gravitational energyis the energy in an object t h a t i s h e l d a g a i n s t t h e f o r c e o f g r a v i t y Th e w a t e r i n a d a m i s h e l d a g a i n s t g r a v i t y f o r e x a m p l e Nuclear energyis the energy stored in the released when nucleus of an atom the nucleus is split or joined with other nuclei is It
A World of Energy body obtains chemical energy from the food you eat and converts some of it into motion energy to enable you to move Energy for Good and Bad In the 21st century people use energy in a wide variety of ways to power computers to light and heat homes to fly across the world and to manufacture goods Almost all of that energy comes from fossil fuels such as coal and oil The ability to make use of these ancient stores of energy is one of the greatest technological triumphs of all time but it has downsides too Fossil fuels will run out one day and they are already becoming harder to find and more difficult to extract Burning fossil fuels creates air pollution and has a major impact on the global environment Time to Change Direction Less damaging sources of energy such as the Sun wind and water were in use long before fossil fuels were discovered Those renewable resources are now being reconsidered in a bid to prevent further harm to our environment The technologies to harness that energy are developing rapidly but face many obstacles They are more expensive and the energy sources may be less reliable the wind does not always blow for example More reliable but perhaps more risky technologies such as nuclear power could solve that problem However the safety concerns and unknown long-term effects make nuclear energy an unpopular choice for many people Whatever direction energy takes in the future science and technology will play a key role in what is possible affordable and acceptable This book explores some of the options and considers the developments in each energy source over recent decades Energy is essential for everything we do from unconscious actions such as breathing to the conscious actions of playing sports such as basketball 5
