EUES - Nonrenewable Energy Sources (Lesson)
Nonrenewable Energy Sources
Use of Energy Resources
Look at the circle graph in the figure below. It shows that oil (petroleum) is the single most commonly used energy resource in the U.S., followed by natural gas, and then by coal. All of these energy resources are nonrenewable. Nonrenewable resources are resources that are limited in supply and cannot be replaced as quickly as they are used up. Renewable resources, in contrast, provide only 9 percent of all energy used in the U.S. Renewable resources are natural resources that can be replaced in a relatively short period of time or are virtually limitless in supply. They include solar energy from sunlight, geothermal energy from under Earth's surface, wind, biomass (from once-living things or their wastes), and hydropower (from running water).
Oil Use by Nation
People in the U.S. use far more energy—especially energy from oil—than people in any other nation. The bar graph in the Figure below compares the amount of oil used by the top ten oil-using nations. The U.S. uses more oil than several other top-ten countries combined. If you also consider the population size in these countries, the differences are even more stunning. The average person in the U.S. uses a whopping 23 barrels of oil a year! In comparison, the average person in India or China uses just 1 or 2 barrels of oil a year.
What Are Nonrenewable Resources?
Nonrenewable resources are natural resources that are limited in supply and cannot be replaced as quickly as they are used up. A natural resource is anything people can use that comes from nature. Energy resources are some of the most important natural resources because everything we do requires energy. Nonrenewable energy resources include fossil fuels such as oil and the radioactive element uranium.
Types of Fossil Fuels
Oil, or petroleum, is one of several fossil fuels. Fossil fuels are mixtures of hydrocarbons (compounds containing only hydrogen and carbon) that formed over millions of years from the remains of dead organisms. In addition to oil, they include coal and natural gas. Fossil fuels provide most of the energy used in the world today. They are burned in power plants to produce electrical energy, and they also fuel cars, heat homes, and supply energy for many other purposes.
Q: Why do fossil fuels have energy?
A: Fossil fuels contain stored chemical energy that originally came from the sun
How Fossil Fuels Formed
When ancient plants underwent photosynthesis, they changed the energy in sunlight to store chemical energy in food. The plants used the food and so did the organisms that ate the plants. After the plants and other organisms died, their remains gradually changed to fossil fuels as they were covered and compressed by layers of sediments. Petroleum and natural gas are formed from ocean organisms and are found together. Coal is formed from giant tree ferns and other swamp plants.
Please watch this video on coal formation.
Click here to view "How was coal formed?" Links to an external site.
Fossil Fuels and the Environment
When fossil fuels burn, they release thermal energy, water vapor, and carbon dioxide. Thermal energy can be used to generate electricity or do other work. Carbon dioxide is released into the atmosphere and is a major cause of global climate change. The burning of fossil fuels also releases many pollutants into the air. Pollutants such as sulfur dioxide from acid rain, which kill living things and damages metals, stonework, and other materials. Pollutants such as nitrogen oxides cause smog, which is harmful to human health. Tiny particles, or particulates, released when fossil fuels burn also harm human health.
The table below shows the amounts of pollutants released by different fossil fuels. Natural gas releases the least pollution; coal releases the most. Petroleum has the additional risk of oil spills, which may seriously damage ecosystems.
Q: Some newer models of cars and other motor vehicles can run on natural gas. Why would a natural gas vehicle be better for the environment than a vehicle that burns gasoline, which is made from oil?
ANSWER: Natural gas produces much less pollution and carbon dioxide when it burns than gasoline does. So a natural gas vehicle would contribute less to global climate change, acid rain, and air pollution that harms health. Besides being better for the environment, burning natural gas instead of gasoline results in less engine wear and provides more energy for a given amount of fuel.
Nuclear Energy
Like fossil fuels, the radioactive element uranium can be used to generate electrical energy in power plants. This source of energy is known as nuclear energy. In a nuclear power plant, the nuclei of uranium atoms are split apart into smaller nuclei in the process of nuclear fission. This process releases a tremendous amount of energy from just a small amount of uranium. The total supply of uranium in the world is quite limited, however, and cannot be replaced once it is used up. That's why nuclear energy is a nonrenewable resource. The use of nuclear energy also produces dangerous radioactive wastes. In addition, accidents at nuclear power plants have the potential to release large amounts of harmful radiation into the environment.
Q: Why is nuclear energy often considered to be "greener" than energy from fossil fuels?
ANSWER: Unlike energy from fossil fuels, nuclear energy (use) doesn't produce air pollution or carbon dioxide that contributes to global climate change.
World's Oil Production Peaks
Oil
Oil Formation
Oil from the ground is called crude oil, which is a mixture of many different hydrocarbons. Crude oil is a thick dark brown or black liquid hydrocarbon. Oil also forms from buried dead organisms, but these are tiny organisms that live on the sea surface and then sink to the seafloor when they die. The dead organisms are kept away from oxygen by layers of other dead creatures and sediments. As the layers pile up, heat and pressure increase. Over millions of years, the dead organisms turn into liquid oil.
Oil Production
In order to be collected, the oil must be located between a porous rock layer and an impermeable layer. Trapped above the porous rock layer and beneath the impermeable layer, the oil will remain between these layers until it is extracted from the rock.
Pump Jack
Pump Jack Diagram
To separate the different types of hydrocarbons in crude oil for different uses, the crude oil must be refined in refineries like the one shown in the images below. Refining is possible because each hydrocarbon in crude oil boils at a different temperature. When the oil is boiled in the refinery, separate equipment collects the different compounds.
Below is a picture of an oil refinery located at Martinez, California. The tapering vertical elements are smokestacks to create drafts for heating units. Most of the complex vertical units are fractionating towers. Others are flares.
Crude Oil Fractional Distillation
Oil Use
Most of the compounds that come out of the refining process are fuels, such as gasoline, diesel, and heating oil. Because these fuels are rich sources of energy and can be easily transported, oil provides about 90% of the energy used for transportation around the world. The rest of the compounds from crude oil are used for waxes, plastics, fertilizers, and other products.
Gasoline is in a convenient form for use in cars and other transportation vehicles. In a car engine, the burned gasoline mostly turns into carbon dioxide and water vapor. The fuel releases most of its energy as heat, which causes the gases to expand. This creates enough force to move the pistons inside the engine and to power the car.
Consequences of Oil Use
The United States does produce oil, but can only produce one-third as much as the nation requires (or uses); the remaining two-thirds comes from importing oil. The United States has only about 1.5% of the world's proven oil reserves, so most of the oil used by Americans must be imported from other nations.
The main oil-producing regions in the United States are the Gulf of Mexico, Texas, Alaska, and California.
Imported Crude Oil as a Percent of U.S. Consumption, 1950-2003
See how you do on the following practice quiz!
Other Uses of Petroleum
Please read the following.
RESOURCES IN THIS MODULE ARE OPEN EDUCATIONAL RESOURCES (OER) OR CREATED BY GAVS UNLESS OTHERWISE NOTED. SOME IMAGES USED UNDER SUBSCRIPTION.