Energy Generation from Biomass

Power Generation by Renewables (IMechE Seminar Publications)
By PEP (Professional Engineering Publishers)

• Publisher: Wiley
• Number Of Pages: 332
• Publication Date: 2005-02-18
• ISBN-10 / ASIN: 1860583091
• ISBN-13 / EAN: 9781860583094

Product Description:

Power Generation by Renewables will be essential reading for all those interested in the potential that renewable energy offers including: existing producers and those looking to develop alternative sources of renewable energy; organisations interested in electricity markets; and representatives of government organisations interested in renewable energy.

Key topics include:

• Sustainable sustained growth? Renewable energy: 10 percent by 2010
• Landfill gas – the reliable renewable
• Combined heat and power from the small scale incineration of waste
• Effective risk management in energy from waste projects
• Small hydro from energy recovery in the water supply network
• The technologies available and relative costs associated with reducing CO2 emissions from power stations
• Experience with power generation from biomass
• Experiences of operating a unique hybrid power generation system
• Diversity! Hydropower, hydrogen, transport, and industry.

• links :http://ifile.it/xcvlz87/1860583091__gigle.ws.rar
  

Energy Story

Conclusion

Imagination is more important than knowledge, for knowledge is limited, whereas imagination embraces the entire world - stimulating progress, giving birth to evolution. - Albert Einstein

To make sure we have plenty of energy in the future, it's up to all of us to use energy wisely.

We must all conserve energy and use it efficiently. It's also up to those who will create the new energy technologies of the future.

All energy sources have an impact on the environment. Concerns about the greenhouse effect and global warming, air pollution, and energy security have led to increasing interest and more development in renewable energy sources such as solar, wind, geothermal, wave power and hydrogen.

But we'll need to continue to use fossil fuels and nuclear energy until new, cleaner technologies can replace them. One of you who is reading this might be another Albert Einstein or Marie Curie and find a new source of energy. Until then, it's up to all of us.

The future is ours, but we need energy to get there.

Energy Story

HAPTER 20: Hydrogen and Future Energy Sources

We learned in Chapter 8 that fossil fuels were formed before and during the time of the dinosaurs - when plants and animals died. Their decomposed remains gradually changed over the years to form coal, oil and natural gas. Fossil fuels took millions of years to make. We are using up the fuels formed more than 65 million years ago. They can't be renewed; they can't be made again. We can save fossil fuels by conserving and finding ways to harness energy from seemingly "endless sources," like the sun and the wind.

We can't use fossil fuels forever as they are a non-renewable and finite resource. Some people suggest that we should start using hydrogen.

Hydrogen is a colorless, odorless gas that accounts for 75 percent of the entire universe's mass. Hydrogen is found on Earth only in combination with other elements such as oxygen, carbon and nitrogen. To use hydrogen, it must be separated from these other elements.

Today, hydrogen is used primarily in ammonia manufacturing, petroleum refining and synthesis of methanol. It's also used in NASA's space program as fuel for the space shuttles, and in fuel cells that provide heat, electricity and drinking water for astronauts. Fuel cells are devices that directly convert hydrogen into electricity. In the future, hydrogen could be used to fuel vehicles (such as the DaimlerChrysler NeCar 4 shown in the picture to the right) and aircraft, and provide power for our homes and offices.

Hydrogen can be made from molecules called hydrocarbons by applying heat, a process known as "reforming" hydrogen. This process makes hydrogen from natural gas. An electrical current can also be used to separate water into its components of oxygen and hydrogen in a process called electrolysis. Some algae and bacteria, using sunlight as their energy source, give off hydrogen under certain conditions.

Hydrogen as a fuel is high in energy, yet a machine that burns pure hydrogen produces almost zero pollution. NASA has used liquid hydrogen since the 1970s to propel rockets and now the space shuttle into orbit. Hydrogen fuel cells power the shuttle's electrical systems, producing a clean by-product - pure water, which the crew drinks.

You can think of a fuel cell as a battery that is constantly replenished by adding fuel to it - it never loses its charge.

To view a FLASH video of how a fuel cell works, go to the Ballard Power Systems website.

Fuel Cell Uses

Fuel cells are a promising technology for use as a source of heat and electricity in buildings, and as an electrical power source for vehicles.

Auto companies are working on building cars and trucks that use fuel cells. In a fuel cell vehicle, an electrochemical device converts hydrogen (stored on board) and oxygen from the air into electricity, to drive an electric motor and power the vehicle.

Although these applications would ideally run off pure hydrogen, in the near term they are likely to be fueled with natural gas, methanol or even gasoline. Reforming these fuels to create hydrogen will allow the use of much of our current energy infrastructure - gas stations, natural gas pipelines, etc. - while fuel cells are phased in.

In the future, hydrogen could also join electricity as an important energy carrier. An energy carrier stores, moves and delivers energy in a usable form to consumers.

Renewable energy sources, like the sun, can't produce energy all the time. The sun doesn't always shine. But hydrogen can store this energy until it is needed and can be transported to where it is needed.

Some experts think that hydrogen will form the basic energy infrastructure that will power future societies, replacing today's natural gas, oil, coal, and electricity infrastructures. They see a new "hydrogen economy" to replace our current "fossil fuel-based economy," although that vision probably won't happen until far in the future.

Solar Power Satellites

One suggestion for energy in the future is to put huge solar power satellites into orbit around the earth. They would collect solar energy from the sun, convert it to electricity and beam it to Earth as microwaves or some other form of transmission. The power would have no greenhouse gas emissions, but microwave beams might affect health adversely. And frequent rocket launches may harm the upper atmosphere. This idea may not be practical for another century; if at all.

The picture on the right is an early and simple drawing of how a space solar power satellite would beam energy to electrical power grid on Earth.

Other Ideas

Some people have claimed they've invented a machine that will "save the planet." Others are convinced that there's a vast conspiracy by fossil fuel and / or nuclear power companies to stop such devices from getting to the public.

Some of these contraptions use theories called "Free Energy," "Over Unity" or "Zero-Point Energy." As a matter of fact, you can find all sorts of information about such devices on the Internet. Just plug in any of those words.

But none of these devices have ever been proven, either theoretically or physically. The "free energy" area is filled with con artists selling unintelligible information, often clouded with technical sounding jargon, and seeking people with money to develop their inventions or ideas.

As the old saying goes, "a fool and his money are soon parted."

Most of these devices are perpetual motion machines, which violate known laws of science. Even the U.S. Patent Office will not issue a patent for such devices. With energy and the universe (at least as we know it today), there's no such thing as a free lunch; or free energy. You can't get energy from nothing because of the fundamental laws of physics that energy cannot be created or destroyed.

What about matter and anti-matter? What about energy that they use on Star Trek and in other science fiction stories? The ideas are interesting, but they are still fiction. Though science fiction has a basis in some fact. Jules Verne wrote about traveling under the water more than a hundred years ago, and today we have submarines. He also wrote about going to the moon, and in 1969 humans first set foot on our closest neighbor in space.

So, while some ideas being used by writers are fiction... there could be some basis in fact. Who knows, someone might create a mater-antimatter energy system that could revolutionize the way we think about energy and our universe.

Energy Story

Chapter 19: Saving Energy and Energy Conservation

picture of recyclin center. Some of the energy we can use is called renewable energy. These include solar, wind, geothermal and hydro. These types of energy are constantly being renewed or restored.

But many of the other forms of energy we use in our homes and cars are not being replenished. Fossil fuels took millions of years to create. They cannot be made over night.

And there are finite or limited amounts of these non-renewable energy sources. That means they cannot be renewed or replenished. Once they are gone they cannot be used again. So, we must all do our part in saving as much energy as we can.

Aerogel material, Lawrence Berkeley National Laboratory, Advanced Technologies Department. In your home, you can save energy by turning off appliances, TVs and radios that are not being used, watched or listened to.

You can turn off lights when no one is in the room.

By putting insulation in walls and attics, we can reduce the amount of energy it takes to heat or cool our homes.


Insulating a home is like putting on a sweater or jacket when we're cold...instead of turning up the heat.

The outer layers trap the heat inside, keeping it nice and warm.

New space-age materials are being developed that insulate even better. This person's fingers are protected by Aerogel Insulation Material created by the Lawrence Berkeley National Laboratory. The person cannot even feel the flame!


Recycling
To make all of our newspapers, aluminum cans, plastic bottles and other goods takes lots of energy.

picture of recyclin center. Recycling these items -- grinding them up and reusing the material again -- uses less energy than it takes to make them from brand new, raw material.

So, we must all recycle as much as we can.

We can also save energy in our cars and trucks.

Make sure the tires are properly inflated.

A car that is tuned up, has clean air and oil filters, and is running right will use less gasoline.

Don't over-load a car. For every extra 100 pounds, you cut your mileage by one mile per gallon.

When your parents buy a new car, tell them to compare the fuel efficiency of different models and buy a car that gets higher miles per gallon.

picture of recyclin center. You can also save energy in your school.

Each week you can choose an energy monitor who will make sure energy is being used properly.

The energy monitor will turn off the lights during recess and after class.

You can make "Turn It Off" signs for hanging above the light switches to remind yourself.

Also check out our on-line pages on Saving Energy.


You can make sure your classmates recycle all aluminum cans and plastic bottles, and make sure the library is recycling the newspapers and the school is recycling its paper.

Chapter 18: Energy for Transportation

Picture of traffic on freeway at night. In California, about one-half of ALL the energy we use goes into transportation - cars, planes, trucks, motorcycles, trains, buses. And of all the oil we use in the state about three-quarters of all it goes into making gasoline and diesel fuel for vehicles.

As we learned in Chapter 8, oil goes through a refinery where it is made into many different products. Some of them are used for transportation: aviation fuel, gasoline and diesel fuel. From the refinery and larger storage tank farms, transportation fuels are usually trucked to service stations in tanker trucks. These trucks can hold 10,000 gallons in each tank. The tanker trucks deliver the gasoline to the services stations.

At service stations, the two grades of gasoline, regular and premium, are kept in separate underground storage tanks. When you pump the gasoline into your car, you are pumping it from those tanks below ground. Mid-grade gasoline is a combination of the two types. Other vehicles, such as trucks and some cars use diesel fuel, which is also made from oil. It is brought to service stations the same way.

California has more than 26 million vehicles on its roads. All the vehicles in the state used 14.4 billion gallons of gasoline in 2001. That's more gasoline that all other countries except for the United States and the former Soviet Union. This makes California the third-largest user of gasoline in the world!

Picture of truck on freeway. Fourteen billion gallons of gasoline is enough to fill a line of 10,000 gallon tanker trucks stretched bumper to bumper from San Francisco to San Diego, back to San Francisco, and then part of the way to Sacramento!

Burning gasoline, however, creates air pollution. That's why oil companies are creating newer types of gasoline that are cleaner than the kind we use today. Beginning in 1996, all the gasoline sold in California will be this newer, cleaner type called "reformulated gasoline." The main ingredient in that gas, however, MTBE was found to hurt water supplies if it leaked. So, that additive is being removed by 2005.

Another concern about using oil for transportation is that a lot of oil used comes form the Middle East. This makes the U.S. very vulnerable if there is political unrest. During the 1970s, Americans saw long lines at the gas pumps because oil from the Middle East was turned off by the Oil Producing Exposting Countries - OPEC. And we're in in worse shape in 2002 because we're importing more and more oil form the Middle East than ever before.

Methanol Alternative Fuel Vehicle. Because of concerns about air pollution and petroleum-dependence, new clean-burning fuels made from fuels other than oil are being introduced. These fuels include methanol, ethanol, natural gas, propane and even electricity. The car on the right uses methanol, the same fuel used in Indianapolis Speedway race cars.

All these fuels are called alternative fuels because they are an alternative to gasoline and diesel. Cars and trucks that use them are called Alternative Fuel Vehicles or AFVs.

Right now, there are only a small number of cars and trucks that are running on fuels other than gasoline and diesel. Energy officials hope, however, that one-quarter of all the vehicles will run on alternative fuels by the year 2025.

For more on alternative fuel vehicles, we have a whole section on Energy Quest. Go to our Transportation Section.

Energy Story

CHAPTER 17: Renewable Energy vs. Fossil Fuels

In Chapter 8, we discussed the world's supply of fossil fuels -- oil, coal and natural gas and how it is being depleted slowly because of constant use. Fossil fuels are not renewable, they can't be made again. Once they are gone, they're gone.

In Chapters 11 to 16, we learned that there's no shortage of renewable energy from the sun, wind and water and even stuff usually thought of as garbage -- dead trees, tree branches, yard clippings, left-over crops, sawdust, even livestock manure, can produce electricity and fuels -- resources collectively called "biomass."

The sunlight falling on the United States in one day contains more than twice the energy we consume in an entire year. California has enough wind gusts to produce 11 percent of the world's wind electricity. Clean energy sources can be harnessed to produce electricity, process heat, fuel and valuable chemicals with less impact on the environment.

In contrast, emissions from cars fueled by gasoline and factories and other facilities that burn oil affect the atmosphere. Foul air results in so-called greenhouse gases. About -81% of all U.S. greenhouse gases are carbon dioxide emissions from energy-related sources.

Renewable energy resource development will result in new jobs for people and less oil we have to buy from foreign countries. According to the federal government, America spent $109 billion to import oil in 2000. If we fully develop self-renewing resources, we will keep the money at home to help the economy.

Continued research has made renewable energy more affordable today than 25 years ago. The cost of wind energy has declined from 40� per kilowatt-hour to less than 5�. The cost of electricity from the sun, through photovoltaics (literally meaning "light-electricity") has dropped from more than $1/kilowatt-hour in 1980 to nearly 20�/kilowatt-hour today. And ethanol fuel costs have plummeted from $4 per gallon in the early 1980s to $1.20 today.

But there are also drawbacks to renewable energy development.

For example, solar thermal energy involving the collection of solar rays through collectors (often times huge mirrors) need large tracts of land as a collection site. This impacts the natural habitat, meaning the plants and animals that live there. The environment is also impacted when the buildings, roads, transmission lines and transformers are built. The fluid most often used with solar thermal electric generation is very toxic and spills can happen.

Solar or PV cells use the same technologies as the production of silicon chips for computers. The manufacturing process uses toxic chemicals. Toxic chemicals are also used in making batteries to store solar electricity through the night and on cloudy days.. Manufacturing this equipment has environmental impacts.

Also, even if we wanted to switch to solar energy right away, we still have a big problem. All the solar production facilities in the entire world only make enough solar cells to produce about 350 megawatts, about enough for a city of 300,000 people. that's a drop in the bucket compared to our needs. California alone needs about 55,000 megawatts of electricity on a sunny, hot summer day. And the cost of producing that much electricity would be about four times more expensive than a regular natural gas-fired power plant.

So, even though the renewable power plant doesn't release air pollution or use precious fossil fuels, it still has an impact on the environment.

Wind power development too, has its downside, mostly involving land use. The average wind farm requires 17 acres of land to produce one megawatt of electricity, about enough electricity for 750 to 1,000 homes. However, farms and cattle grazing can use the same land under the wind turbines.

Wind farms could cause erosion in desert areas. Most often, winds farms affect the natural view because they tend to be located on or just below ridgelines. Bird deaths also occur due to collisions with wind turbines and associated wires. This issue is the subject of on-going research.

Producing geothermal electricity from the earth's crust tends to be localized. That means facilities have to be built where geothermal energy is abundant. There are several geothermal resource locations in California. The Geysers area north of San Francisco is an example. In the course of geothermal production, steam coming from the ground becomes very caustic at times, causing pipes to corrode and fall apart. Geothermal power plants sometimes cost a little bit more than a gas-fired power plant because they have to include the cost to drill.

Environmental concerns are associated with dams to produce hydroelectric power. People are displaced and prime farmland and forests are lost in the flooded areas above dams. Downstream, dams change the chemical, physical and biological characteristics of the river and land.

Unlike fossil fuels, which dirties the atmosphere, renewable energy has less impact on the environment Renewable energy production has some drawbacks, mainly associated with the use of large of tracts of land that affects animal habitats and outdoor scenery. Renewable energy development will result in jobs and less oil imported from foreign countries.

Note: For those working on a school assignment comparing renewable vs. non-renewable energy, we'd suggest creating a Pro and Con list for each energy source. That will give you a a way to compare the various energy resources.

Energy Story

Chapter 16: Wind Energy

Wind can be used to do work. The kinetic energy of the wind can be changed into other forms of energy, either mechanical energy or electrical energy. When a boat lifts a sail, it is using wind energy to push it through the water. This is one form of work. Farmers have been using wind energy for many years to pump water from wells using windmills like the one on the right. In Holland, windmills have been used for centuries to pump water from low-lying areas. Wind is also used to turn large grinding stones to grind wheat or corn, just like a water wheel is turned by water power. Today, the wind is also used to make electricity. Blowing wind spins the blades on a wind turbine -- just like a large toy pinwheel. This device is called a wind turbine and not a windmill. A windmill grinds or mills grain, or is used to pump water. The blades of the turbine are attached to a hub that is mounted on a turning shaft. The shaft goes through a gear transmission box where the turning speed is increased. The transmission is attached to a high speed shaft which turns a generator that makes electricity. If the wind gets too high, the turbine has a brake that will keep the blades from turning too fast and being damaged. You can use a single smaller wind turbine to power a home or a school. The small turbine on the right makes enough energy for a house. In the picture on the left, the children at this Iowa school are playing beneath a wind turbine that makes enough electricity to power their entire school. We have many windy areas in California. And wind is blowing in many places all over the earth. The only problem with wind is that it is not windy all the time. In California, it is usually windier during the summer months when wind rushes inland from cooler areas, like the ocean to replace hot rising air in California's warm central valleys and deserts. In order for a wind turbine to work efficiently, wind speeds usually must be above 12 to 14 miles per hour. Wind has to be this speed to turn the turbines fast enough to generate electricity. The turbines usually produce about 50 to 300 kilowatts of electricity each. A kilowatt is 1,000 watts (kilo means 1,000). You can light ten 100 watt light bulbs with 1,000 watts. So, a 300 kilowatt (300,000 watts) wind turbine could light up 3,000 light bulbs that use 100 watts! As of 1999, there were 11,368 wind turbines in California. These turbines are grouped together in what are called wind "farms," like those in Palm Springs in the picture on the right. These wind farms are located mostly in the three windiest areas of the state: Altamont Pass, east of San Francisco San Gorgonio Pass, near Palm Springs Tehachapi, south of Bakersfield Together these three places in California make enough electricity to supply an entire city the size of San Francisco! About 11 percent of the entire world's wind-generated electricity is found in California. Other countries that use a lot of wind energy are Denmark and Germany. Once electricity is made by the turbine, the electricity from the entire wind farm is collected together and sent through a transformer. There the voltage is increase to send it long distances over high power lines.

Chapter 15: Solar Energy

We have always used the energy of the sun as far back as humans have existed on this planet. As far back as 5,000 years ago, people "worshipped" the sun. Ra, the sun-god, who was considered the first king of Egypt. In Mesopotamia, the sun-god Shamash was a major deity and was equated with justice. In Greece there were two sun deities, Apollo and Helios. The influence of the sun also appears in other religions - Zoroastrianism, Mithraism, Roman religion, Hinduism, Buddhism, the Druids of England, the Aztecs of Mexico, the Incas of Peru, and many Native American tribes.

We know today, that the sun is simply our nearest star. Without it, life would not exist on our planet. We use the sun's energy every day in many different ways.

When we hang laundry outside to dry in the sun, we are using the sun's heat to do work -- drying our clothes.

Plants use the sun's light to make food. Animals eat plants for food. And as we learned in Chapter 5, decaying plants hundreds of millions of years ago produced the coal, oil and natural gas that we use today. So, fossil fuels is actually sunlight stored millions and millions of years ago.

Indirectly, the sun or other stars are responsible for ALL our energy. Even nuclear energy comes from a star because the uranium atoms used in nuclear energy were created in the fury of a nova - a star exploding.

Let's look at ways in which we can use the sun's energy.

Solar Hot Water

In the 1890s solar water heaters were being used all over the United States. They proved to be a big improvement over wood and coal-burning stoves. Artificial gas made from coal was available too to heat water, but it cost 10 times the price we pay for natural gas today. And electricity was even more expensive if you even had any in your town!

Many homes used solar water heaters. In 1897, 30 percent of the homes in Pasadena, just east of Los Angeles, were equipped with solar water heaters. As mechanical improvements were made, solar systems were used in Arizona, Florida and many other sunny parts of the United States. The picture shown here is a solar water heater installed on the front roof of a house in Pomona Valley, California, in 1911 (the panels are circled above the four windows).

By 1920, ten of thousands of solar water heaters had been sold. By then, however, large deposits of oil and natural gas were discovered in the western United States. As these low cost fuels became available, solar water systems began to be replaced with heaters burning fossil fuels.

Today, solar water heaters are making a comeback. There are more than half a million of them in California alone! They heat water for use inside homes and businesses. They also heat swimming pools like in the picture.

Panels on the roof of a building, like this one on the right, contain water pipes. When the sun hits the panels and the pipes, the sunlight warms them.

That warmed water can then be used in a swimming pool.

Solar Thermal Electricity

Solar energy can also be used to make electricity.

Some solar power plants, like the one in the picture to the right in California's Mojave Desert, use a highly curved mirror called a parabolic trough to focus the sunlight on a pipe running down a central point above the curve of the mirror. The mirror focuses the sunlight to strike the pipe, and it gets so hot that it can boil water into steam. That steam can then be used to turn a turbine to make electricity.

In California's Mojave desert, there are huge rows of solar mirrors arranged in what's called "solar thermal power plants" that use this idea to make electricity for more than 350,000 homes. The problem with solar energy is that it works only when the sun is shining. So, on cloudy days and at night, the power plants can't create energy. Some solar plants, are a "hybrid" technology. During the daytime they use the sun. At night and on cloudy days they burn natural gas to boil the water so they can continue to make electricity.

Another form of solar power plants to make electricity is called a Central Tower Power Plant, like the one to the right - the Solar Two Project.

Sunlight is reflected off 1,800 mirrors circling the tall tower. The mirrors are called heliostats and move and turn to face the sun all day long.

The light is reflected back to the top of the tower in the center of the circle where a fluid is turned very hot by the sun's rays. That fluid can be used to boil water to make steam to turn a turbine and a generator.

This experimental power plant is called Solar II. It was re-built in California's desert using newer technologies than when it was first built in the early 1980s. Solar II will use the sunlight to change heat into mechanical energy in the turbine.

The power plant will make enough electricity to power about 10,000 homes. Scientists say larger central tower power plants can make electricity for 100,000 to 200,000 homes.

Solar Cells or Photovoltaic Energy

We can also change the sunlight directly to electricity using solar cells. Solar cells are also called photovoltaic cells - or PV cells for short - and can be found on many small appliances, like calculators, and even on spacecraft. They were first developed in the 1950s for use on U.S. space satellites. They are made of silicon, a special type of melted sand. When sunlight strikes the solar cell, electrons (red circles) are knocked loose. They move toward the treated front surface (dark blue color). An electron imbalance is created between the front and back. When the two surfaces are joined by a connector, like a wire, a current of electricity occurs between the negative and positive sides. These individual solar cells are arranged together in a PV module and the modules are grouped together in an array. Some of the arrays are set on special tracking devices to follow sunlight all day long. The electrical energy from solar cells can then be used directly. It can be used in a home for lights and appliances. It can be used in a business. Solar energy can be stored in batteries to light a roadside billboard at night. Or the energy can be stored in a battery for an emergency roadside cellular telephone when no telephone wires are around. Some experimental cars also use PV cells. They convert sunlight directly into energy to power electric motors on the car. But when most of us think of solar energy, we think of satellites in outer space. Here's a picture of solar panels extending out from a satellite.

Energy Story

Chapter 14: Ocean Energy

The world's ocean may eventually provide us with energy to power our homes and businesses. Right now, there are very few ocean energy power plants and most are fairly small. But how can we get energy from the ocean?

There are three basic ways to tap the ocean for its energy. We can use the ocean's waves, we can use the ocean's high and low tides, or we can use temperature differences in the water. Let's take a look at each.

Wave Energy

Kinetic energy (movement) exists in the moving waves of the ocean. That energy can be used to power a turbine. In this simple example, to the right, the wave rises into a chamber. The rising water forces the air out of the chamber. The moving air spins a turbine which can turn a generator.

When the wave goes down, air flows through the turbine and back into the chamber through doors that are normally closed.

This is only one type of wave-energy system. Others actually use the up and down motion of the wave to power a piston that moves up and down inside a cylinder. That piston can also turn a generator.

Most wave-energy systems are very small. But, they can be used to power a warning buoy or a small light house.

Tidal Energy

Another form of ocean energy is called tidal energy. When tides comes into the shore, they can be trapped in reservoirs behind dams. Then when the tide drops, the water behind the dam can be let out just like in a regular hydroelectric power plant.

Tidal energy has been used since about the 11th Century, when small dams were built along ocean estuaries and small streams. the tidal water behind these dams was used to turn water wheels to mill grains.

In order for tidal energy to work well, you need large increases in tides. An increase of at least 16 feet between low tide to high tide is needed. There are only a few places where this tide change occurs around the earth. Some power plants are already operating using this idea. One plant in France makes enough energy from tides (240 megawatts) to power 240,000 homes.

This facility is called the La Rance Station in France. It began making electricity in 1966. It produces about one fifth of a regular nuclear or coal-fired power plant. It is more than 10 times the power of the next largest tidal station in the world, the 17 megawatt Canadian Annapolis station.

Ocean Thermal Energy Conversion (OTEC)

The idea is not new. Using the temperature of water to make energy actually dates back to 1881 when a French Engineer by the name of Jacques D'Arsonval first thought of OTEC. The final ocean energy idea uses temperature differences in the ocean. If you ever went swimming in the ocean and dove deep below the surface, you would have noticed that the water gets colder the deeper you go. It's warmer on the surface because sunlight warms the water. But below the surface, the ocean gets very cold. That's why scuba divers wear wet suits when they dive down deep. Their wet suits trapped their body heat to keep them warm.

Power plants can be built that use this difference in temperature to make energy. A difference of at least 38 degrees Fahrenheit is needed between the warmer surface water and the colder deep ocean water.

Using this type of energy source is called Ocean Thermal Energy Conversion or OTEC. It is being demonstrated in Hawaii. More info on OTEC can be found on the archive pages for the Natural Energy Laboratory of Hawaii at: www.hawaii.gov/dbedt/ert/otec-nelha/otec.html

Energy Story

Chapter 13: Nuclear Energy - Fission and Fusion

Another major form of energy is nuclear energy, the energy that is trapped inside each atom. One of the laws of the universe is that matter and energy can't be created nor destroyed. But they can be changed in form.

Matter can be changed into energy. The world's most famous scientist, Albert Einstein, created the mathematical formula that explains this. It is:

E = m c ²

This equation says:

E [energy] equals m [mass] times c² [c stands for the velocity or the speed of light. c² means c times c, or the speed of light raised to the second power -- or c-squared.]

You can listen to Einstein's voice explaining this at: www.aip.org/history/einstein/voice1.htm

Please note that some web browser software may not show an exponent (raising something to a power, a mathematical expression) on the Internet. Normally c-squared is shown with a smaller "2" placed above and to the right of the c.

Scientists used Einstein's famous equation as the key to unlock atomic energy and also create atomic bombs.

The ancient Greeks said the smallest part of nature is an atom. But they did not know 2,000 years ago about nature's even smaller parts.

As we learned in chapter 2, atoms are made up of smaller particles -- a nucleus of protons and neutrons, surrounded by electrons which swirl around the nucleus much like the earth revolves around the sun.

Nuclear Fission

An atom's nucleus can be split apart. When this is done, a tremendous amount of energy is released. The energy is both heat and light energy. Einstein said that a very small amount of matter contains a very LARGE amount of energy. This energy, when let out slowly, can be harnessed to generate electricity. When it is let out all at once, it can make a tremendous explosion in an atomic bomb.

A nuclear power plant (like Diablo Canyon Nuclear Plant shown on the right) uses uranium as a "fuel." Uranium is an element that is dug out of the ground many places around the world. It is processed into tiny pellets that are loaded into very long rods that are put into the power plant's reactor.

The word fission means to split apart. Inside the reactor of an atomic power plant, uranium atoms are split apart in a controlled chain reaction.

In a chain reaction, particles released by the splitting of the atom go off and strike other uranium atoms splitting those. Those particles given off split still other atoms in a chain reaction. In nuclear power plants, control rods are used to keep the splitting regulated so it doesn't go too fast.

If the reaction is not controlled, you could have an atomic bomb. But in atomic bombs, almost pure pieces of the element Uranium-235 or Plutonium, of a precise mass and shape, must be brought together and held together, with great force. These conditions are not present in a nuclear reactor.

The reaction also creates radioactive material. This material could hurt people if released, so it is kept in a solid form. The very strong concrete dome in the picture is designed to keep this material inside if an accident happens.

This chain reaction gives off heat energy. This heat energy is used to boil water in the core of the reactor. So, instead of burning a fuel, nuclear power plants use the chain reaction of atoms splitting to change the energy of atoms into heat energy.

This water from around the nuclear core is sent to another section of the power plant. Here, in the heat exchanger, it heats another set of pipes filled with water to make steam. The steam in this second set of pipes turns a turbine to generate electricity. Below is a cross section of the inside of a typical nuclear power plant.

Power plant drawing courtesy Nuclear Institute

Nuclear Fusion

Another form of nuclear energy is called fusion. Fusion means joining smaller nuclei (the plural of nucleus) to make a larger nucleus. The sun uses nuclear fusion of hydrogen atoms into helium atoms. This gives off heat and light and other radiation.

In the picture to the right, two types of hydrogen atoms, deuterium and tritium, combine to make a helium atom and an extra particle called a neutron.

Also given off in this fusion reaction is energy! Thanks to the University of California, Berkeley for the picture.

Scientists have been working on controlling nuclear fusion for a long time, trying to make a fusion reactor to produce electricity. But they have been having trouble learning how to control the reaction in a contained space.

What's better about nuclear fusion is that it creates less radioactive material than fission, and its supply of fuel can last longer than the sun.

Energy Story

Chapter 11: Geothermal Energy

Geothermal Energy has been around for as long as the Earth has existed. "Geo" means earth, and "thermal" means heat. So, geothermal means earth-heat.

Have you ever cut a boiled egg in half? The egg is similar to how the earth looks like inside. The yellow yolk of the egg is like the core of the earth. The white part is the mantle of the earth. And the thin shell of the egg, that would have surrounded the boiled egg if you didn't peel it off, is like the earth's crust.

Below the crust of the earth, the top layer of the mantle is a hot liquid rock called magma. The crust of the earth floats on this liquid magma mantle. When magma breaks through the surface of the earth in a volcano, it is called lava.

For every 100 meters you go below ground, the temperature of the rock increases about 3 degrees Celsius. Or for every 328 feet below ground, the temperature increases 5.4 degrees Fahrenheit. So, if you went about 10,000 feet below ground, the temperature of the rock would be hot enough to boil water.

Deep under the surface, water sometimes makes its way close to the hot rock and turns into boiling hot water or into steam. The hot water can reach temperatures of more than 300 degrees Fahrenheit (148 degrees Celsius). This is hotter than boiling water (212 degrees F / 100 degrees C). It doesn't turn into steam because it is not in contact with the air.

When this hot water comes up through a crack in the earth, we call it a hot spring, like Emerald Pool at Yellowstone National Park pictured on the left. Or, it sometimes explodes into the air as a geyser, like Old Faithful Geyser pictured on the right.

About 10,000 years ago, Paleo-Indians used hot springs in North American for cooking. Areas around hot springs were neutral zones. Warriors of fighting tribes would bathe together in peace. Every major hot spring in the United States can be associated with Native American tribes. California hot springs, like at the Geysers in the Napa area, were important and sacred areas to tribes from that area.

In other places around the world, people used hot springs for rest and relaxation. The ancient Romans built elaborate buildings to enjoy hot baths, and the Japanese have enjoyed natural hot springs for centuries.

Geothermal Today

Today, people use the geothermally heated hot water in swimming pools and in health spas. Or, the hot water from below the ground can warm buildings for growing plants, like in the green house on the right.

In San Bernardino, in Southern California, hot water from below ground is used to heat buildings during the winter. The hot water runs through miles of insulated pipes to dozens of public buildings. The City Hall, animal shelters, retirement homes, state agencies, a hotel and convention center are some of the buildings which are heated this way.

In the Country of Iceland, many of the buildings and even swimming pools in the capital of Reykjavik (RECK-yah-vick) and elsewhere are heated with geothermal hot water. The country has at least 25 active volcanoes and many hot springs and geysers.

Geothermal Electricity

Hot water or steam from below ground can also be used to make electricity in a geothermal power plant.

In California, there are 14 areas where we use geothermal energy to make electricity. The red areas on the map show where there are known geothermal areas. Some are not used yet because the resource is too small, too isolated or the water temperatures are not hot enough to make electricity.

The main spots are:

• The Geysers area north of San Francisco
• In the northwest corner of the state near Lassen Volcanic National Park
• In the Mammoth Lakes area - the site of a huge ancient volcano
• In the Coso Hot Springs area in Inyo County
• In the Imperial Valley in Southern California.

Some of the areas have so much steam and hot water that it can be used to generate electricity. Holes are drilled into the ground and pipes lowered into the hot water, like a drinking straw in a soda. The hot steam or water comes up through these pipes from below ground.

You can see the pipes running in front of the geothermal power plant in the picture. This power plant is Geysers Unit # 18 located in the Geysers Geothermal area of California.

A geothermal power plant is like in a regular power plant except that no fuel is burned to heat water into steam. The steam or hot water in a geothermal power plant is heated by the earth. It goes into a special turbine. The turbine blades spin and the shaft from the turbine is connected to a generator to make electricity. The steam then gets cooled off in a cooling tower.

The white "smoke" rising from the plants in the photograph above is not smoke. It is steam given off in the cooling process. The cooled water can then be pumped back below ground to be reheated by the earth.

Here's a cut-away showing the inside of the power plant. The hot water flows into turbine and out of the turbine. The turn turns the generator, and the electricity goes out to the transformer and then to the huge transmission wires that link the power plants to our homes, school and businesses. We learned about transmission lines in Chapter 7.

California's geothermal power plants produce about one-half of the world's geothermally generated electricity. The geothermal power plants produce enough electricity for about two million homes.

Geothermal / Ground Source Heat Pumps

Though it gets much hotter as we go deep below ground, the upper layer of the earth close to the surface is not very hot.

Almost everywhere across the entire planet, the upper 10 feet below ground level stays the same temperature, between 50 and 60 degrees Fahrenheit (10 and 16 degrees C). If you've ever been in a basement of a building or in a cavern below ground, the temperature of the area is almost always cool.

A geothermal or ground source heat pump system can use that constant temperature to heat or cool a building. Pipes are buried in the ground near the building. Inside these pipes a fluid, like the antifreeze in a car radiator, is circulated.

In winter, heat from the warmer ground goes through the heat exchanger of a heat pump, which sends warm air into the home or business. During hot weather, the process is reversed. Hot air from inside the building goes through the heat exchanger and the heat is passed into the relatively cooler ground. Heat removed during the summer can also be used to heat water.

For another FLASH "movie" about how ground source heat pumps work, go to the GeoExchange website at:
http://www.ghpc.org/about/movie.htm.

Energy Story

Chapter 11: Geothermal Energy

Geothermal Energy has been around for as long as the Earth has existed. "Geo" means earth, and "thermal" means heat. So, geothermal means earth-heat.

Have you ever cut a boiled egg in half? The egg is similar to how the earth looks like inside. The yellow yolk of the egg is like the core of the earth. The white part is the mantle of the earth. And the thin shell of the egg, that would have surrounded the boiled egg if you didn't peel it off, is like the earth's crust.

Below the crust of the earth, the top layer of the mantle is a hot liquid rock called magma. The crust of the earth floats on this liquid magma mantle. When magma breaks through the surface of the earth in a volcano, it is called lava.

For every 100 meters you go below ground, the temperature of the rock increases about 3 degrees Celsius. Or for every 328 feet below ground, the temperature increases 5.4 degrees Fahrenheit. So, if you went about 10,000 feet below ground, the temperature of the rock would be hot enough to boil water.

Deep under the surface, water sometimes makes its way close to the hot rock and turns into boiling hot water or into steam. The hot water can reach temperatures of more than 300 degrees Fahrenheit (148 degrees Celsius). This is hotter than boiling water (212 degrees F / 100 degrees C). It doesn't turn into steam because it is not in contact with the air.

When this hot water comes up through a crack in the earth, we call it a hot spring, like Emerald Pool at Yellowstone National Park pictured on the left. Or, it sometimes explodes into the air as a geyser, like Old Faithful Geyser pictured on the right.

About 10,000 years ago, Paleo-Indians used hot springs in North American for cooking. Areas around hot springs were neutral zones. Warriors of fighting tribes would bathe together in peace. Every major hot spring in the United States can be associated with Native American tribes. California hot springs, like at the Geysers in the Napa area, were important and sacred areas to tribes from that area.

In other places around the world, people used hot springs for rest and relaxation. The ancient Romans built elaborate buildings to enjoy hot baths, and the Japanese have enjoyed natural hot springs for centuries.

Geothermal Today

Today, people use the geothermally heated hot water in swimming pools and in health spas. Or, the hot water from below the ground can warm buildings for growing plants, like in the green house on the right.

In San Bernardino, in Southern California, hot water from below ground is used to heat buildings during the winter. The hot water runs through miles of insulated pipes to dozens of public buildings. The City Hall, animal shelters, retirement homes, state agencies, a hotel and convention center are some of the buildings which are heated this way.

In the Country of Iceland, many of the buildings and even swimming pools in the capital of Reykjavik (RECK-yah-vick) and elsewhere are heated with geothermal hot water. The country has at least 25 active volcanoes and many hot springs and geysers.

Geothermal Electricity

Hot water or steam from below ground can also be used to make electricity in a geothermal power plant.

In California, there are 14 areas where we use geothermal energy to make electricity. The red areas on the map show where there are known geothermal areas. Some are not used yet because the resource is too small, too isolated or the water temperatures are not hot enough to make electricity.

The main spots are:

• The Geysers area north of San Francisco
• In the northwest corner of the state near Lassen Volcanic National Park
• In the Mammoth Lakes area - the site of a huge ancient volcano
• In the Coso Hot Springs area in Inyo County
• In the Imperial Valley in Southern California.

Some of the areas have so much steam and hot water that it can be used to generate electricity. Holes are drilled into the ground and pipes lowered into the hot water, like a drinking straw in a soda. The hot steam or water comes up through these pipes from below ground.

You can see the pipes running in front of the geothermal power plant in the picture. This power plant is Geysers Unit # 18 located in the Geysers Geothermal area of California.

A geothermal power plant is like in a regular power plant except that no fuel is burned to heat water into steam. The steam or hot water in a geothermal power plant is heated by the earth. It goes into a special turbine. The turbine blades spin and the shaft from the turbine is connected to a generator to make electricity. The steam then gets cooled off in a cooling tower.

The white "smoke" rising from the plants in the photograph above is not smoke. It is steam given off in the cooling process. The cooled water can then be pumped back below ground to be reheated by the earth.

Here's a cut-away showing the inside of the power plant. The hot water flows into turbine and out of the turbine. The turn turns the generator, and the electricity goes out to the transformer and then to the huge transmission wires that link the power plants to our homes, school and businesses. We learned about transmission lines in Chapter 7.

California's geothermal power plants produce about one-half of the world's geothermally generated electricity. The geothermal power plants produce enough electricity for about two million homes.

Geothermal / Ground Source Heat Pumps

Though it gets much hotter as we go deep below ground, the upper layer of the earth close to the surface is not very hot.

Almost everywhere across the entire planet, the upper 10 feet below ground level stays the same temperature, between 50 and 60 degrees Fahrenheit (10 and 16 degrees C). If you've ever been in a basement of a building or in a cavern below ground, the temperature of the area is almost always cool.

A geothermal or ground source heat pump system can use that constant temperature to heat or cool a building. Pipes are buried in the ground near the building. Inside these pipes a fluid, like the antifreeze in a car radiator, is circulated.

In winter, heat from the warmer ground goes through the heat exchanger of a heat pump, which sends warm air into the home or business. During hot weather, the process is reversed. Hot air from inside the building goes through the heat exchanger and the heat is passed into the relatively cooler ground. Heat removed during the summer can also be used to heat water.

For another FLASH "movie" about how ground source heat pumps work, go to the GeoExchange website at:
http://www.ghpc.org/about/movie.htm.

Energy Story

Chapter 10: Biomass Energy

Biomass is matter usually thought of as garbage. Some of it is just stuff lying around -- dead trees, tree branches, yard clippings, left-over crops, wood chips (like in the picture to the right), and bark and sawdust from lumber mills. It can even include used tires and livestock manure.

Your trash, paper products that can't be recycled into other paper products, and other household waste are normally sent to the dump. Your trash contains some types of biomass that can be reused. Recycling biomass for fuel and other uses cuts down on the need for "landfills" to hold garbage.

This stuff nobody seems to want can be used to produce electricity, heat, compost material or fuels. Composting material is decayed plant or food products mixed together in a compost pile and spread to help plants grow.

California produces more than 60 million bone dry tons of biomass each year. Of this total, five million bone dry tons is now burned to make electricity. This is biomass from lumber mill wastes, urban wood waste, forest and agricultural residues and other feed stocks.

If all of it was used, the 60 million tons of biomass in California could make close to 2,000 megawatts of electricity for California's growing population and economy. That's enough energy to make electricity for about two million homes!

How biomass works is very simple. The waste wood, tree branches and other scraps are gathered together in big trucks. The trucks bring the waste from factories and from farms to a biomass power plant. Here the biomass is dumped into huge hoppers. This is then fed into a furnace where it is burned. The heat is used to boil water in the boiler, and the energy in the steam is used to turn turbines and generators (see Chapter 8).

Biomass can also be tapped right at the landfill with burning waster products. When garbage decomposes, it gives off methane gas. You'll remember in chapters 8 and 9 that natural gas is made up of methane. Pipelines are put into the landfills and the methane gas can be collected. It is then used in power plants to make electricity. This type of biomass is called landfill gas.

A similar thing can be done at animal feed lots. In places where lots of animals are raised, the animals - like cattle, cows and even chickens - produce manure. When manure decomposes, it also gives off methane gas similar to garbage. This gas can be burned right at the farm to make energy to run the farm.

Using biomass can help reduce global warming compared to a fossil fuel-powered plant. Plants use and store carbon dioxide (CO2) when they grow. CO2 stored in the plant is released when the plant material is burned or decays. By replanting the crops, the new plants can use the CO2 produced by the burned plants. So using biomass and replanting helps close the carbon dioxide cycle. However, if the crops are not replanted, then biomass can emit carbon dioxide that will contribute toward global warming.

So, the use of biomass can be environmentally friendly because the biomass is reduced, recycled and then reused. It is also a renewable resource because plants to make biomass can be grown over and over.

Today, new ways of using biomass are still being discovered. One way is to produce ethanol, a liquid alcohol fuel. Ethanol can be used in special types of cars that are made for using alcohol fuel instead of gasoline. The alcohol can also be combined with gasoline. This reduces our dependence on oil - a non-renewable fossil fuel.

DID YOU KNOW THAT
ELEPHANTS CAN MAKE ENERGY!
CLICK THE PICTURE TO FIND OUT MORE....

CLICK HERE TO SEE A FLASH MOVIE
OF HOW BIOMASS POWER WORKS...
This file is VERY large. DO NOT click on this is you're using a regular modem. You need a FAST Internet connection like DSL, cable modem or LAN!

Energy Story

Chapter 9: Natural Gas Distribution System

We learned in Chapter 8 that natural gas is a fossil fuel. It is a gaseous molecule that's made up of two atoms - one carbon atom combined with four hydrogen atom. It's chemical formula is CH4. The picture on the right is a model of what the molecule could look like.

Don't confuse natural gas with "gasoline," which we call "gas" for short. Like oil, natural gas is found under ground and under the ocean floor. Wells are drilled to tap into natural gas reservoirs just like drilling for oil. Once a drill has hit an area that contains natural gas, it can be brought to the surface through pipes.

The natural gas has to get from the wells to us. To do that, there is a huge network of pipelines that brings natural gas from the gas fields to us. Some of these pipes are two feet wide.

Natural gas is sent in larger pipelines to power plants to make electricity or to factories because they use lots of gas. Bakeries use natural gas to heat ovens to bake bread, pies, pastries and cookies. Other businesses use natural gas for heating their buildings or heating water.

From larger pipelines, the gas goes through smaller and smaller pipes to your neighborhood.

In businesses and in your home, the natural gas must first pass through a meter, which measures the amount of fuel going into the building. A gas company worker reads the meter and the company will charge you for the amount of natural gas you used.

In some homes, natural gas is used for cooking, heating water and heating the house in a furnace.

In rural areas, where there are no natural gas pipelines, propane (another form of gas that's often made when oil is refined) or bottled gas is used instead of natural gas. Propane is also called LPG, or liquefied petroleum gas, is made up of methane and a mixture with other gases like butane.

Propane turns to a liquid when it is placed under slight pressure. For regular natural gas to turn into a liquid, it has to be made very, very cold.

Cars and trucks can also use natural gas as a transportation fuel, but they must carry special cylinder-like tanks to hold the fuel.

When natural gas is burned to make heat or burned in a car's engine, it burns very cleanly. When you combine natural gas with oxygen (the process of combustion), you produce carbon dioxide and water vapor; plus the energy that's released in heat and light.

Some impurities are contained in all natural gas. These include sulphur and butane and other chemicals. When burned, those impurities can create air pollution. The amount of pollution from natural gas is less than burning a more "complex" fuel like gasoline. Natural gas-powered cars are more than 90 percent cleaner than a gasoline-powered car.

That's why many people feel natural gas would be a good fuel for cars because it burns cleanly.

Energy Story

Chapter 8: Fossil Fuels - Coal, Oil and Natural Gas

Where Fossil Fuels Come From

There are three major forms of fossil fuels: coal, oil and natural gas. All three were formed many hundreds of millions of years ago before the time of the dinosaurs - hence the name fossil fuels. The age they were formed is called the Carboniferous Period. It was part of the Paleozoic Era. "Carboniferous" gets its name from carbon, the basic element in coal and other fossil fuels.

The Carboniferous Period occurred from about 360 to 286 million years ago. At the time, the land was covered with swamps filled with huge trees, ferns and other large leafy plants, similar to the picture above. The water and seas were filled with algae - the green stuff that forms on a stagnant pool of water. Algae is actually millions of very small plants.

Some deposits of coal can be found during the time of the dinosaurs. For example, thin carbon layers can be found during the late Cretaceous Period (65 million years ago) - the time of Tyrannosaurus Rex. But the main deposits of fossil fuels are from the Carboniferous Period. For more about the various geologic eras, go to www.ucmp.berkeley.edu/help/timeform.html

As the trees and plants died, they sank to the bottom of the swamps of oceans. They formed layers of a spongy material called peat. Over many hundreds of years, the peat was covered by sand and clay and other minerals, which turned into a type of rock called sedimentary.

More and more rock piled on top of more rock, and it weighed more and more. It began to press down on the peat. The peat was squeezed and squeezed until the water came out of it and it eventually, over millions of years, it turned into coal, oil or petroleum, and natural gas.

Coal

Coal is a hard, black colored rock-like substance. It is made up of carbon, hydrogen, oxygen, nitrogen and varying amounts of sulphur. There are three main types of coal - anthracite, bituminous and lignite. Anthracite coal is the hardest and has more carbon, which gives it a higher energy content. Lignite is the softest and is low in carbon but high in hydrogen and oxygen content.� Bituminous is in between. Today, the precursor to coal - peat - is still found in many countries and is also used as an energy source.

The earliest known use of coal was in China. Coal from the Fu-shun mine in northeastern China may have been used to smelt copper as early as 3,000 years ago. The Chinese thought coal was a stone that could burn.

Coal is found in many of the lower 48 states of U.S. and throughout the rest of the world. Coal is mined out of the ground using various methods. Some coal mines are dug by sinking vertical or horizontal shafts deep under ground, and coal miners travel by elevators or trains deep under ground to dig the coal. Other coal is mined in strip mines where huge steam shovels strip away the top layers above the coal. The layers are then restored after the coal is taken away.

The coal is then shipped by train and boats and even in pipelines. In pipelines, the coal is ground up and mixed with water to make what's called a slurry. This is then pumped many miles through pipelines. At the other end, the coal is used to fuel power plants and other factories.

Oil or Petroleum

Oil is another fossil fuel. It was also formed more than 300 million years ago. Some scientists say that tiny diatoms are the source of oil. Diatoms are sea creatures the size of a pin head. They do one thing just like plants; they can convert sunlight directly into stored energy.

In the graphic on the left, as the diatoms died they fell to the sea floor (1). Here they were buried under sediment and other rock (2). The rock squeezed the diatoms and the energy in their bodies could not escape. The carbon eventually turned into oil under great pressure and heat. As the earth changed and moved and folded, pockets where oil and natural gas can be found were formed (3).

Oil has been used for more than 5,000-6,000 years. The ancient Sumerians, Assyrians and Babylonians used crude oil and asphalt ("pitch") collected from large seeps at Tuttul (modern-day Hit) on the Euphrates River. A seep is a place on the ground where the oil leaks up from below ground. The ancient Egyptians, used liquid oil as a medicine for wounds, and oil has been used in lamps to provide light.

The Dead Sea, near the modern Country of Israel, used to be called Lake Asphaltites. The word asphalt was derived is from that term because of the lumps of gooey petroleum that were washed up on the lake shores from underwater seeps.

In North America, Native Americans used blankets to skim oil off the surface of streams and lakes. They used oil as medicine and to make canoes water-proof. During the Revolutionary War, Native Americans taught George Washington's troops how to treat frostbite with oil.

As our country grew, the demand for oil continued to increase as a fuel for lamps. Petroleum oil began to replace whale oil in lamps because the price for whale oil was very high. During this time, most petroleum oil came from distilling coal into a liquid or by skimming it off of lakes - just as the Native Americans did.

Then on August 27, 1859, Edwin L. Drake (the man standing on the right in the black and white picture to the right), struck liquid oil at his well near Titusville, Pennsylvania. He found oil under ground and a way that could pump it to the surface. The well pumped the oil into barrels made out of wood. This method of drilling for oil is still being used today all over the world in areas where oil can be found below the surface.

Oil and natural gas are found under ground between folds of rock and in areas of rock that are porous and contain the oils within the rock itself. The folds of rock were formed as the earth shifts and moves. It's similar to how a small, throw carpet will bunch up in places on the floor.

To find oil and natural gas, companies drill through the earth to the deposits deep below the surface. The oil and natural gas are then pumped from below the ground by oil rigs (like in the picture). They then usually travel through pipelines or by ship.

Oil is found in 18 of the 58 counties in California. Kern County, the County where Bakersfield is found, is one of the largest oil production places in the country. But we only get one-half of our oil from California wells. The rest comes from Alaska, and an increasing amount comes from other countries. In the entire U.S., more than 50 percent of all the oil we use comes from outside the country...most of it from the Middle East.

Oil is brought to California by large tanker ships. The petroleum or crude oil must be changed or refined into other products before it can be used.

Refineries

Oil is stored in large tanks until it is sent to various places to be used. At oil refineries, crude oil is split into various types of products by heating the thick black oil.

Oil is made into many different products - fertilizers for farms, the clothes you wear, the toothbrush you use, the plastic bottle that holds your milk, the plastic pen that you write with. They all came from oil. There are thousands of other products that come from oil. Almost all plastic comes originally from oil. Can you think of some other things made from oil?

The products include gasoline, diesel fuel, aviation or jet fuel, home heating oil, oil for ships and oil to burn in power plants to make electricity. Here's what a barrel of crude oil can make.

In California, 74 percent of our oil is used for transportation -- cars, planes, trucks, buses and motorcycles. We'll learn more about transportation energy in Chapter 18.

Source: American Petroleum Institute (www.api.org). Figures are based on 1995 average yields for U.S. refineries. One barrel contains 42 gallons of crude oil. The total volume of products made is 44.2 GALLONS - 2.2 gallons greater than the original 42 gallons of crude oil. This is called "processing gain," where other chemicals are added to the refining process to create the products.

Natural Gas

Sometime between 6,000 to 2,000 years BCE (Before the Common Era), the first discoveries of natural gas seeps were made in Iran. Many early writers described the natural petroleum seeps in the Middle East, especially in the Baku region of what is now Azerbaijan. The gas seeps, probably first ignited by lightning, provided the fuel for the "eternal fires" of the fire-worshiping religion of the ancient Persians.

Natural gas is lighter than air. Natural gas is mostly made up of a gas called methane. Methane is a simple chemical compound that is made up of carbon and hydrogen atoms. It's chemical formula is CH4 - one atom of carbon along with four atoms hydrogen. This gas is highly flammable.

Natural gas is usually found near petroleum underground. It is pumped from below ground and travels in pipelines to storage areas. The next chapter looks at that pipeline system.

Natural gas usually has no odor and you can't see it. Before it is sent to the pipelines and storage tanks, it is mixed with a chemical that gives a strong odor. The odor smells almost like rotten eggs. The odor makes it easy to smell if there is a leak.

Energy Safety Note! If you smell that rotten egg smell in your house, tell your folks and get out of the house quickly. Don't turn on any lights or other electrical devices. A spark from a light switch can ignite the gas very easily. Go to a neighbor's house and call 9-1-1 for emergency help.

Saving Fossil Fuels

Fossil fuels take millions of years to make. We are using up the fuels that were made more than 300 million years ago before the time of the dinosaurs. Once they are gone they are gone.

So, it's best to not waste fossil fuels. They are not renewable; they can't really be made again. We can save fossil fuels by conserving energy.