Presentation on theme: "Energy 101 LT #1 I can describe what energy is. LT #2 I can identify and explain the sources of energy. LT #3 I can identify and explain the forms of energy."— Presentation transcript:
Energy 101 LT #1 I can describe what energy is. LT #2 I can identify and explain the sources of energy. LT #3 I can identify and explain the forms of energy.
What is Energy? Energy is the ability to do work. Energy is in everything! We use energy for everything we do, from making a jump shot to baking cookies to sending astronauts into space. Energy makes change possible. Modern civilization is possible because we have learned how to change energy from one form to another and use it to do work for use and to live more comfortably. We use it to do things for us. It moves cars along the road and boats over the water. It bakes a cake in the oven and keeps ice frozen in the freezer. It plays our favorite songs on the radio and lights our homes. Energy is needed for our bodies to grow and it allows our minds to think.
Energy Sources When we use electricity in our home, the electrical power was probably generated by burning coal, by a nuclear reaction, or by a hydroelectric plant at a dam. Therefore, coal, nuclear and hydro are called energy sources. When we fill up a gas tank, the source might be petroleum or ethanol made by growing the processing corn. Energy sources are divided into two groups – renewable (an energy source that can be easily replenished) and nonrenewable (an energy source that we are using up and cannot recreate).
Renewable Energy Sources Solar Geothermal Wind Hydropower (water) Biomass wood and wood waste municipal solid waste landfill gas and biogas ethanol biodiesel Many paper mills use wood waste to produce steam and electricity
What Role Does Renewable Energy Play in the United States? The use of renewable energy is not new. More than 150 years ago, wood, which is one form of biomass, supplied up to 90% of our energy needs. As the use of coal, petroleum, and natural gas expanded, the United States became less reliant on wood as an energy source. Today, we are looking again at renewable sources to find new ways to use them to help meet our energy needs. Over half of renewable energy goes to producing electricity. The next largest use of renewable energy is biomass (wood and waste) for the production of heat and steam for industrial purposes and for space heating, mostly in homes. Biomass also includes biofuels, such as ethanol and biodiesel, used for transportation.
What Role Does Renewable Energy Play in the United States? Renewable energy plays an important role in the supply of energy. When renewable energy sources are used, the demand for fossil fuels is reduced. Unlike fossil fuels, non- biomass renewable sources of energy (hydropower, geothermal, wind, and solar) do not directly emit greenhouse gases. Radiant energy from the sun has powered life on Earth for many millions of years.
Why Don’t We Use More Renewable Energy? In the past, renewable energy has generally been more expensive to produce and use than fossil fuels. Renewable resources are often located in remote areas, and it is expensive to build power lines to the cities where the electricity they produce is needed. The use of renewable sources is also limited by the fact that they are not always available — cloudy days reduce solar power; calm days reduce wind power; and droughts reduce the water available for hydropower. Wind Farm at The Cerro Gordo Project, West of Mason City, Iowa
Why Don’t We Use More Renewable Energy? The production and use of renewable fuels has grown more quickly in recent years as a result of higher prices for oil and natural gas, and a number of state and federal government incentives, including the Energy Policy Acts of 2002 and 2005. The use of renewable fuels is expected to continue to grow over the next 30 years, although EIA projects that we will still rely on non-renewable fuels to meet most of our energy needs.
Nonrenewable Energy Sources Propane Uranium (nuclear energy) Coal Natural Gas Petroleum Gasoline Diesel fuel Nonrenewable energy sources come out of the ground as liquids, gases, and solids. Crude oil (petroleum) is the only commercial nonrenewable fuel that is naturally in liquid form. Natural gas and propane are normally gases, and coal is a solid.
Fossil Fuels Are Nonrenewable, but Not All Nonrenewable Energy Sources Are Fossil Fuels Coal, petroleum, natural gas, and propane are all considered fossil fuels because they were formed from the buried remains of plants and animals that lived millions of years ago. Uranium ore, a solid, is mined and converted to a fuel used at nuclear power plants. Uranium is not a fossil fuel, but is a nonrenewable fuel.
Forms of Energy Potential Energy – stored energy Chemical Mechanical Nuclear Gravitational Kinetic Energy – motion of waves, electrons, atoms, molecules, substances, and objects Radiant Thermal Sound Motion Electrical
Chemical Energy is energy stored in the bonds of atoms and molecules. Batteries, biomass, petroleum, natural gas, and coal are examples of stored chemical energy. Chemical energy is converted to thermal energy when we burn wood in a fireplace or burn gasoline in a car's engine.
Mechanical Energy is energy stored in objects by tension. Compressed springs and stretched rubber bands are examples of stored mechanical energy.
Nuclear Energy is energy stored in the nucleus of an atom — the energy that holds the nucleus together. Very large amounts of energy can be released when the nuclei are combined or split apart. Nuclear power plants split the nuclei of uranium atoms in a process called fission. The sun combines the nuclei of hydrogen atoms in a process called fusion.
Gravitational Energy is energy stored in an object's height. The higher and heavier the object, the more gravitational energy is stored. When you ride a bicycle down a steep hill and pick up speed, the gravitational energy is being converted to motion energy. Hydropower is another example of gravitational energy, where the dam "piles" up water from a river into a reservoir.
Radiant Energy is electromagnetic energy that travels in transverse waves. Radiant energy includes visible light, x-rays, gamma rays and radio waves. Light is one type of radiant energy. Sunshine is radiant energy, which provides the fuel and warmth that make life on Earth possible.
Thermal Energy or heat, is the vibration and movement of the atoms and molecules within substances. As an object is heated up, its atoms and molecules move and collide faster. Geothermal energy is the thermal energy in the Earth.
Sound Energy is the movement of energy through substances in longitudinal (compression/rarefaction) waves. Sound is produced when a force causes an object or substance to vibrate — the energy is transferred through the substance in a wave. Typically, the energy in sound is far less than other forms of energy.
Motion Energy is energy stored in the movement of objects. The faster they move, the more energy is stored. It takes energy to get an object moving, and energy is released when an object slows down. Wind is an example of motion energy. A dramatic example of motion is a car crash, when the car comes to a total stop and releases all its motion energy at once in an uncontrolled instant.
Electrical Energy is delivered by tiny charged particles called electrons, typically moving through a wire. Lightning is an example of electrical energy in nature, so powerful that it is not confined to a wire.