Energy Sources Chapter 9

Using Energy Where does our energy come from? How do we obtain our energy? What types of energy are available?

What is Efficiency? Efficiency is the amount of work put in versus the amount of work gotten out. Efficiency = output work (J)/input work (J) x 100

Non-Renewable Resources Include petroleum, natural gas, coal, and nuclear power. They cannot be replaced by natural processes at the rate which they are used.

What are Fossil Fuels?

Petroleum Is a flammable liquid formed from decayed ancient organisms. It is made up of hydrocarbons. Is used to make gasoline, heating oil, and asphalt. Is used to make plastics and synthetic fibers.

What’s in a barrel of petroleum?

How Petroleum is Formed Million Years Ago Million Years Ago Today

Natural Gas Is formed through the same process as petroleum. Mostly made up of methane, CH4. Also contains butane and propane. Is used to provide energy for cooking, heating, and manufacturing. Contains more energy per kilogram and burns more cleanly than other fossil fuels.

Coal Is a solid fossil fuel that is mined underground. 25% of all energy used in the United States comes from coal. 90% of all coal used in the United States is used in power plants to generate electricity times more coal than petroleum. It is the most inefficient and polluting of the fossil fuels. It contains sulfur and nitrogen compounds.

How Coal is Formed 300 million years ago plants died and formed peat which is an accumulation of partially decayed vegetable matter. The layer of peat was covered with a layer of sediment. The peat is compressed and forms lignite which is 25%-35% carbon. It accounts for 7% of the coal mined in the United States. The lignite is compressed with high heat and pressure to form bituminous coal which is 45-86% carbon. It accounts for over half of the coal production in the United States. The bituminous coal is further compressed to anthracite which is 86-97% carbon. It accounts for.5% of the coal mined in the United States.

Using Fossil Fuels to Generate Electricity Chemical to Thermal 60% efficient Water to steam 90% efficient Overall 35% EfficientTurbine spinning the generator 95% efficient Transmission through power lines 90% efficient Steam turning the turbine 75% efficient

Costs of Using Fossil Fuels Burning Fossil Fuels gives off smoke that contains particulates and CO 2. Particulates can cause breathing problems. CO 2 contributes to the warming of the Earth. Coal is the most abundant but is of the lowest quality. Sulfur compounds in coal can cause acid rain. Fossil Fuels are a NON-RENEWABLE resource.

Why are Fossil Fuels non-renewable?

Nuclear Power Is a non-renewable resource Uses nuclear reactors to generate power Produces 8% of all energy consumed in the United States. Generates nuclear waste

Nuclear Reactors Use nuclear fuel, usually Uranium-235 Contain fuel rods, control rods, and cooling systems. Uses the energy of controlled nuclear reactions to generate heat Works through a process called fission

Fission

Generating Electricity with Nuclear Power

Renewable Resources Includes solar, geothermal, wind, hydroelectric, and alternative fuels. Can be replaced by natural processes or use natural processes.

Solar Power Can use photovoltaic cells to convert sunlight into energy Photovoltaic cells are made up of two layers of semiconducters It is 7-11 % efficient Solar Power is more expensive than using fossil fuels Solar Power Plants concentrate the suns rays to boil water and generate electricity.

Geothermal Power Uses the heat of the Earth to generate electricity Has an efficiency of 16% Low to no pollution Can only be used where magma is close to the surface

Wind Power Uses wind to turn turbines and generate electricity Causes no pollution They are 20% efficient There are few places where wind blows consistently with enough power to turn windmills

Hydroelectric Power Hydroelectricity uses the power of moving water to generate electricity Uses a dam to convert potential energy to kinetic energy Produces 8% of the electrical energy used in the United States It is 60% efficient since it does not use heat exchange Disturb natural ecosystems

Alternative Fuels Ethanol - can be made from corn or sugarcane Biodiesal – can be made from waste grease Hydrogen fuel cells Biomass – renewable organic matter used to obtain energy Biomass is one of the oldest forms of power and includes wood, sugar cane fibers, rice hulls, and manure

Energy Consumption

Where does the Energy Come From? From Radioactive Decay Geothermal Nuclear Power From the Sun Fossil Fuels Solar Power Hydroelectric Ethanol Wind Power Biomass Geothermal Nuclear Power Biomass Ethanol Hydroelectric Wind PowerSolar Power Fossil Fuels