Unit VII Energy What is energy Energy is

Unit VII Energy

What is energy? • Energy is the ability to do work and transfer heat. – It comes in many forms:

Energy Terms • Kinetic Energy – Matter that has energy because of its mass and speed. – Electromagnetic Spectrum – Heat – Temperature

Energy Terms • Potential Energy – Stored energy that has the potential to do work. – High quality energy – Low quality energy

Energy Terms • Entropy – Measurement of the disorder of energy. – Higher entropy = less useful • Physical Change • Chemical Change

Energy Terms • Nuclear Change – Nuclei of certain isotopes change into one or more different isotopes. – Radioactive Decay • Radiocarbon dating

Energy Laws • 1 st Law of Thermodynamics (AKA: Law of Conservation of Energy) So why worry about the loss of resources? • 2 nd Law of Thermodynamics

Developed vs. Developing Usage

Energy Resources • Where do we get our energy from? – World • Nonrenewable resources • Renewable resources – US (the largest user of energy) • Nonrenewable resources • Renewable resources

US Energy Usage (2011)

US Energy Efficiency & Sustainability 1. Increase Energy Efficiency and Conservation a. Requires many unpopular decisions i. Decrease speed limits ii. Eliminate government subsidies 2. Secure Future Fossil Fuel Energy Supplies a. Oppositions: i. environmental and economic 3. Develop Alternative Energy Sources a. Who pays for this? b. Gas taxes? 4. Meet the First Three Objectives Without Further Damage to the Environment

Energy Cost Comparison

Energy Resources • Basic Power Production – How do we make electricity? ? ? – Most power plants, no matter what type of fuel source utilized, create electricity in the same basic manner.

Basic Coal-Fired Power Plant

Non-Renewable Energy • Fossil Fuels – Most widely used source of energy in developed countries. – Derived from decomposition of buried plant and animal matter trapped under high temperature & pressure for millions of years. – Oil & Natural Gas – Coal

Coal • World’s most abundant fuel • Composed primarily of carbon

Coal • Formed in several stages

Coal • Coal Reserves • Coal Production

Coal • How do we extract coal? – Subsurface Mining • Used for coal reserves deep underground • Traditional “mines” • Very expensive and dangerous but less environmental damage – Surface Mining • used for coal nearer the surface • causes the most environmental damage • Area strip mining • Contour strip mining • Open Pit Mining • Mountain Top Mining

Coal • Surface Mining Control and Reclamation Act (1977) – Requires filling (reclaiming) of surface mines after mining – Reduces Acid Mine Drainage – Requires permits and inspections of active coal mining sights – Prohibits coal mining in sensitive areas

Coal • Coal Burning: – Releases large quantities of CO 2 into atmosphere • Greenhouse gas – Releases other pollutants into atmosphere – Can cause acid precipitation

Coal • Can reduce air pollutants using: – electrostatic precipitators – scrubbers – fluidized boilers

Coal • Pros • Cons

Crude Oil/Petroleum • Primary Oil Recovery • Secondary Oil Recovery • Primary + Secondary Recovery • Tertiary Oil Recovery

Crude Oil/Petroleum • Various Derivatives – Refining process separates various hydrocarbons based on boiling points. – Common derivatives

Crude Oil/Petroleum • Petrochemicals – By-products of distillation process include components used in:

Crude Oil/Petroleum • Oil Reserves & OPEC – Top Proven Oil Reserves

Crude Oil/Petroleum • Top Oil Producing Countries

1989 Alaskan Oil Spill • Exxon Valdez hit a reef and spilled 260, 000 barrels of crude oil into sound • Largest oil tanker spill in US history

Keystone Pipeline

Crude Oil/Petroleum • Pros • Cons

Natural Gas • What is it? – Primarily Methane (CH 4) – Can also include other heavy gaseous hydrocarbons – Conventional Natural Gas – Unconventional Natural Gas

Natural Gas • LPG vs. LNG – Liquefied Petroleum Gas – Liquefied Natural Gas

Natural Gas • Top Proven Natural Gas Reserves • Top Natural Gas Producers

Natural Gas • Pros • Cons

Synfuel • Synfuel • Include:

Length of Supplies? ? ? • Difficult to determine and estimates vary • Depends on: • Experts indicate there may be shortages in 21 st century

Fracking – Process of extracting Natural Gas and/or Oil from shale rock deep underground. – Involves injecting a mixture of water and chemicals underground to break up the rock – Global fracking projects have dramatically increased in the last decade (especially in US) – Can be devestating to the surrounding environment

Nuclear Energy • Very expensive and complicated technology. • Nuclear Fission Reactors – atoms of Uranium-235 or Plutonium-239 are split by neutrons which releases energy (heat) – entire reaction occurs in a moderator – controlled by using neutron absorbing control rods

Nuclear Energy

Nuclear Energy

Nuclear Fuel Cycle • Processes involved in producing the fuel used in nuclear reactors and in disposing of radioactive (nuclear) wastes

Nuclear Energy • 441 commercial reactors in 32 countries producing 15% of the world’s electricity. – 60 new reactors currently under construction • 104 reactors in the US producing ~20% of our electricity. – Moratorium on new plants began in 1979. – New ones have been approved and construction has begun however, including one in FL • France heavily relies on nuclear energy – ~77% of France’s power generation – Heavily subsidized by the government

Nuclear Energy • Meltdown

3 Mile Island • 1979 - most serious reactor accident in US • 50% meltdown of reactor core • Elevated public apprehension of nuclear energy

Chernobyl • 1986 - worst accident in history • 1 or 2 explosions destroyed the nuclear reactor • Spread across large portions of Europe

Nuclear Energy • Low-level radioactive waste • High-level radioactive waste • Mill Tailings

Radiation in Perspective

Nuclear Energy • Long term storage of nuclear waste is an ongoing, global problem

Nuclear Energy • US currently stores wastes at “temporary” facilities

Nuclear Energy • Long term storage was planned for Yucca Mountain. • Project has been canceled – environmental concerns – $$$

Nuclear Energy • Licensed to operate for 40 years • Power plants cannot be abandoned when they are shut down • Three solutions

Nuclear Energy • Nuclear Fusion – Fuses two atoms of hydrogen isotopes – Haven’t been able to efficiently fuse atoms

Nuclear Energy • Pros • Cons

Renewable Energy • What are they and where do they come from? – Sources of energy that are potentially sustainable because it can last indefinitely without reducing the original supply.

Solar Power • The sun is the ultimate source of energy for the earth. • Photovoltaic Cells

Solar Power • Active Solar Heating • Traditional Electricity Production

Solar Power • Passive Solar Heating

Solar Power • Pros • Cons

Biomass • Can be any organic material burned • Heavily used in developing nations • Also used to create electricity • Can be converted into biofuels

Biomass • Pros • Cons

Wind • World’s fastest growing energy resource • Winds are harnessed by building turbine “farms” in suitable locations. • Best available sites to harness wind in US are the Great Plains states. • Largest users of wind power is Northern Europe and the US

Wind

Wind • Pros • Cons

Hydropower • 3 methods of electricity production: – Large-scale – Small-scale – Pumped-storage hydropower

Hydropower

China’s 3 Gorges Dam

China’s 3 Gorges Dam

Hydropower • Supplies ~20% of the world’s electricity • Can be high or low quality depending on the situation. • Pros • Cons

Hydropower

Wave Energy • Converts wave energy into electricity • Pros • Cons

Geothermal • Enormous potential energy source • From Hydrothermal Reservoirs

Geothermal • From hot, dry rock • Geothermal heat pumps

Geothermal • Currently used by 24 countries • Pros • Cons

Tidal Energy • Converts tidal energy into electricity • Pros • Cons

Fuel Cell • Device that directly converts chemical energy into electricity

Fuel Cells • Hydrogen and oxygen gases combine to produce electricity. • H combines with O 2 in the air and produces water vapor • Pros • Cons

Micropower • Proponents argue the future will be decentralized small-scale micropower systems. • Produce smaller amounts of electricity on site and disperse any excess to the traditional electrical grid.