Nonrenewable Energy Resources Chapter 12 Nonrenewable Energy Resources

Energy use has consequences 1969 - coast of Santa Barbara CA- 3 million gallons of oil Prompted creation of the first Earth Day: April 22, 1970 1989: Exxon Valdez, Alaska - 53 million gallons. 2010: BP Deepwater Horizon -Gulf of Mexico -206 million gallons of oil – 11 killed 2005: BP oil refinery in Texas. 15 workers killed. 2010: Coal mine explosion -West Virginia. 29 miners killed. Discovery, drilling, extraction, pipelines, transportation, refining, use, disposal All cause pollution, environmental degradation, & human health effects Many of these externalities are not included in price Especially for fossil fuels

Most of our Energy Most of our energy comes from nonrenewable sources that once they are used up, they cannot be replenished). Two main categories: Fossil fuels and Nuclear fuels. What affects the rate at which energy is used? Availability Affordability More recently, environmental impacts. In 2005, U.S. used 5x the world avg Overall, 20% of the world - developed countries use 70% of the energy!

Energy Use By Resource More than 80% of our energy World Annual Energy consumption More than 80% of our energy Comes from fossil fuels

Energy Use Commercial energy sources- those that are bought and sold, such as coal, oil and natural gas. Subsistence energy sources- those gathered by individuals for their own use such as wood, charcoal and animal waste.

Energy History Pre-Industrial – muscles and firewood Industrial – burning wood, then coal Post-industrial – burning a variety of fossil fuels with a variety of renewables

The U.S. produces 70% of the energy it needs. 30% from other countries. Energy use varies both seasonally and regionally. Air conditioning/heating needs. The type of energy used is a function of many factors: ease of transport, amount of energy per mass of fuel

Energy Efficiency Second law of thermodynamics: as a source of energy is transformed its ability to do work diminishes - Heat is lost during conversion at every step incandescent light bulb: 5% internal combustion engine: 15% nuclear power plant: 30% coal burning power plant: 35% photosynthesis : 1% Electricity is clean at the point of use but there are many pollution tradeoffs before that point. Greatest efficiency comes with the fuel that entails the fewest conversions from the original source.

EROEI: Energy return on energy investment) Energy obtained from the fuel Energy invested to obtain the fuel **The bigger the EROEI, the better. Fuels like oil from tar sands require a great deal of energy to extract and refine – lowering their value EROEI =

Transportation efficiency Public transportation is much more efficient. Car efficiency goes up as more people are added. Recent legislation says that by 2016, the overall fleet average MPG must be at 35. (CAFE standards)

U.S. Electricity Generation Mostly from coal

Making Electricity: flow of electrons Burn a fuel source (wood, coal, nuclear) Use heat to produce steam Steam (or flowing water or wind) turns turbines creating a flow of electrons in the generator Electricity is distributed

Creating Electricity Commercial electricity is made by the turning of magnets or electromagnets inside casings of coiled copper wired. The magnets are connected to a turbine which is turned by the force of steam, water or wind flowing past it. Magnets Heat source Wire coils Turbine Transformer

Cogeneration Cogeneration- using a fuel to generate electricity and to produce heat. Example- If steam is used for industrial purposes or to heat buildings it is diverted to turn a turbine first. This improves the efficiency to as high as 90%.

Fossil fuel comparisons

C O A L

What is coal? Coal is fossilized plant material that was subjected to heat and pressure over millions of years. The largest coal reserves are in the United States, Russia, China, Major use: electricity generation www.lander.edu/rlayland/Chem%20103/chap_12.ppt

Coal- a solid fuel formed primarily from the remains of trees, ferns, and other plant materials that were preserved 280-360 million years ago. Four types of coal ranked from lesser to greater age, exposure to pressure, and energy content: lignite, sub-bituminous, bituminous, and anthracite.

Types of Coal Anthracite: Rare, but high quality coal with high energy content; cleanest burning coal Bituminous: Plentiful type of coal with high energy content, but higher sulfur concentrations Subbituminous: Lower heat value, but cleaner burning (less sulfur) Lignite: also called brown coal. Lowest heat value. Youngest coal. Peat: coal precursor made of partially decomposed organic material http://www.ket.org/trips/coal/agsmm/agsmmtypes.html

Bituminous (soft coal) Anthracite (hard coal) Increasing heat and carbon content Increasing moisture content Peat (not a coal) Lignite (brown coal) Bituminous (soft coal) Anthracite (hard coal) Heat Heat Heat Pressure Pressure Pressure Partially decayed plant matter in swamps and bogs; low heat content Low heat content; low sulfur content; limited supplies in most areas Extensively used as a fuel because of its high heat content and large supplies; normally has a high sulfur content Highly desirable fuel because of its high heat content and low sulfur content; supplies are limited in most areas Figure 16.12 Natural capital: stages in coal formation over millions of years. Peat is a soil material made of moist, partially decomposed organic matter. Lignite and bituminous coal are sedimentary rocks, whereas anthracite is a metamorphic rock (Figure 15-8, p. 343). QUESTION: Are there coal deposits near where you live or go to school? Fig. 16-12, p. 368

Environmental Impacts of coal burning SOx, NOx and CO2 production Acid deposition from high sulfur content Release of other air pollutants including particulates, mercury, arsenic, and lead Releases radioactive particles In China, home coal burning exposes families to toxic metals including arsenic and mercury Mining: Acid mine drainage Habitat loss Loss of human lives

Mining for Coal: Habitat destruction (low rate of successful restoration despite 1977 SMCRA law) Erosion & Landslides Airborne dust hazards Tailings can pollute waterways

Advantages and Disadvantages Cons Dirtiest fuel, highest carbon dioxide Major environmental degradation from mining: air pollution and acid rain Major threat to human health Trace metals like mercury, lead, and arsenic released Particulate matter Ash Sulfur Oxides = acid rain Pros Most abundant fossil fuel Major U.S. reserves 200 years. at current consumption rates High net energy yield Infrastructure in place

Petroleum Petroleum- a mixture of hydrocarbons, water, and sulfur that occurs in underground deposits. Formed from the remains of ocean-dwelling phytoplankton that died 50-150 million years ago. Main use: Transportation - gasoline & diesel fuel for vehicles Countries with the most petroleum are Saudi Arabia, Venezuela, Canada, Iraq, Iran, Russia

Petroleum

Sources of Oil Organization of Petroleum Exporting Countries (OPEC) -- 12 countries control 80% of global oil supplies http://www.opec.org/opec_web/en/data_graphs/330.htm

Fractional Distillation Separates out components of crude oil by boiling point. Lighter compounds will boil first and rise.

U.S. Oil Supplies The U.S. – the world’s largest oil user – 2% of world’s reserves U.S oil production peaked in 1974 (halfway production point). About 60% of U.S oil imports goes through refineries in hurricane-prone regions of the Gulf Coast.

Unconventional Oil Much of the easy oil is gone; increasingly difficult and destructive sources are used now Deepwater Drilling Tar Sands Oil Shales

Petroleum Petroleum- a mixture of hydrocarbons, water, and sulfur that occurs in underground deposits. Formed from the remains of ocean-dwelling phytoplankton that died 50-150 million years ago. Oil and gasoline make this ideal for mobile combustion, such as vehicles. Countries with the most petroleum are Saudi Arabia, Russia, the United States, Iran, China, Canada, and Mexico.

Heavy Oils: Tar Sands & Oil Shale: Heavy and tarlike oils from oil sand and oil shale could supplement conventional oil, but there are environmental problems. High sulfur content. Extracting and processing produces: Toxic sludge Uses and contaminates larges volumes of water Requires large inputs of natural gas which reduces net energy yield.

Advantages and Disadvantages of Petroleum Convenient to transport and use Releases carbon dioxide into atmosphere Relatively energy-dense Possibility of leaks when extracted and transported Cleaner-burning than coal Deliberate and accidental releases of waste oil Possible that it might melt permafrost and interfere with the calving of caribou along pipelines Releases sulfur, mercury, lead, and arsenic into the atmosphere when burned

Natural Gas

Natural Gas - Fossil Fuel Mixture 80 -95% Methane (CH4) Other gases: Ethane (C2H6), Propane (C3H8), Butane (C4H10), Hydrogen sulfide (H2S) – TOXIC Formed same way as petroleum (heat and pressure) Mined by pumping it out of the ground Largest uses are for electricity generation and industrial processes in the U.S. Also used for residential heating, clothes dryers, stoves, water heaters. www.bio.miami.edu/beck/esc101/Chapter14&15.ppt

Natural Gas Reserves Conventional Natural Gas Found above crude oil reserves Formed by the same process A natural gas pipeline must be built in oil reserves, otherwise the resource is lost Unconventional Natural Gas Methane hydrates – trapped in ice crystals below the permafrost/ocean sediments  how to get it out?

Sources of Natural Gas Russia & Iran - almost 44% of world's supply. Qatar (13%), Saudi Arabia (4.6%), Algeria (4%), United States (5%), Nigeria (3%), Venezuela (3%); www.bio.miami.edu/beck/esc101/Chapter14&15.ppt

Fracking Process: 1. Locate oil/gas and drill a well up to 10,000 ft deep 2. High Pressure Injection: pump in fluid (water, chemicals, sand) 3. Rock surrounding the well cracks or fractures 4. Oil/gas is released through cracks, travels back up well, and is collected above ground Oil/gas Injection fluid Oil/gas fractures http://www.teachersdomain.org/asset/envh10_vid_fracking/

Locations in the USA Locations Worldwide

Pros Domestic product 1.2 million jobs in US Saves money Makes US less dependent on foreign energy Provides 30% of domestic energy 1.2 million jobs in US Saves money Revives old wells Enables reuse of equipment Profits for site landowners Natural gas produces less air pollution and less CO2 than coal or oil Buys time to develop the technology for alternative energy Pros

Cons Cons Air and Water pollution Chemicals in Injection Fluid Contaminated water from injection fluid - stored in open pits Groundwater pollution: Methane = flammable water Air pollution: VOCs and Nox lead to smog, GHGs to global warming Requires huge quantities of water (1-8 million gallons per fracking operation Chemicals in Injection Fluid 600 different chemicals, many are carcinogens Benzene, Formaldehyde Human health hazards Neurological disorders, Cancer, Birth defects Habitat fragmentation Initially exempt from Clean Air Act and Safe Drinking Water Act (new rules now passed) May contribute to earthquakes Cons

Fracking: waste water wells & earthquakes from 2011 to 2015

Advantages and Disadvantages Natural Gas Contains fewer impurities and therefore emits almost no sulfur dioxide or particulates When unburned, methane escapes into the atmosphere (potent greenhouse gas) Emits only 60% as much carbon dioxide as coal Exploration of natural gas has the potential of contaminating groundwater Large quantities of water used during extraction

The Hubbert Curve Hubbert curve- a graph that shows the point at which world oil production would reach a maximum and the point at which we would run out of oil. He predicted in 1969 that 80% of world reserves would be used up within 60 years.

The Future of Fossil Fuel Use If current global use continues, we will run out of conventional oil in less than 40 years. Coal supplies will last for at least 200 years, and probably much longer. Technological advances in renewable energy will someday make oil less desirable.

Nuclear Energy

Nuclear Energy Often rejected because of concerns over the dangers of nuclear accidents, radioactivity, and weapons. Fission- a nuclear reaction in which a neutron strikes a relatively large atomic nucleus, which then splits into two or more parts.

Nuclear Reactors Uses the same basic principles to create electricity as the coal plant except that a fission reaction (of U-235) provides the heat.

Nuclear Reactors Fuel rods- the cylindrical tubes that house the nuclear fuel used in a nuclear power plant. Nuclear power plants work by using heat from nuclear fission to heat water. This water produces the steam to turn the turbine, which turns a generator. Control rods- cylindrical devices that can be inserted between the fuel rods to absorb excess neutrons, thus slowing or stopping the fission reaction.

Nuclear ore Large commercial uranium mining operations exist in Australia, Western U.S., and parts of Canada. 70% of the electricity generated in France comes from nuclear and it has wide use in Lithuania, Germany, Spain, the UK, Japan, China and South Korea. The U.S. gets 20% of their electricity from nuclear. Currently 104 plants in the U.S.

Trade-Offs Large fuel supply Conventional Nuclear Fuel Cycle Advantages Disadvantages Large fuel supply Cannot compete economically without huge government subsidies Low environmental impact (without accidents) Low net energy yield High environmental impact (with major accidents) Emits 1/6 as much CO2 as coal Moderate land disruption and water pollution (without accidents) Catastrophic accidents can happen (Chernobyl) No widely acceptable solution for long-term storage of radioactive wastes and decommissioning worn-out plants Figure 16.19 Trade-offs: advantages and disadvantages of using the conventional nuclear fuel cycle (Figure 16-18) to produce electricity. QUESTION: Which single advantage and which single disadvantage do you think are the most important? Moderate land use Low risk of accidents because of multiple safety systems (except for 15 Chernobyl-type reactors) Subject to terrorist attacks Spreads knowledge and technology for building nuclear weapons Fig. 16-19, p. 376

Radioactive Waste High-level radioactive waste- the form used in fuel rods. Low-level radioactive waste- the protective clothing, tools, rags, and other items used in routine plant maintenance. Uranium mine tailings- residue left after uranium is mined and enriched.

Radioactive Waste Radioactive waste- once the nuclear fuel can not produce enough heat to be used in a power plant but it continues to emit radioactivity. This waste must be stored in special, highly secure locations because of the danger to living organisms. Cannot be incinerated, disposed of using chemicals, shot into space, dumped on the ocean floor. Remains a threat for 10 half-lives (the accepted number by scientists).

Where to store waste??? 1982 Nuclear Waste Policy Act (NWPA) Federal Government's responsibility Recommendation: Storage/disposal of high level radioactive waste - stable geologic repository deep underground Current disposal: (Not recommended) on location of nuclear power plants – where produced Where to store waste???

Yucca Mountain In 1978 the U.S. department of Energy began examining the Yucca Mountain site in Nevada as a permanent storage area. In 2002, Congress approved Yucca Mountain to serve as the long-term storage facility for all nuclear waste in the U.S. n 2006 the DOE released a report confirming the soundness of the site. In 2011, Project was defunded.

Fusion Nuclear fusion- the reaction that powers the Sun and other stars. This occurs when lighter nuclei are forced together to produce heavier nuclei and heat is released. Fusion is a promising, unlimited source of energy in the future, but so far scientists have had difficulty cotaining the heat that is produced.