Fossil Fuels

Energy Use 85% nonrenewable energy Use of coal Use of oil Nuclear has leveled off Developing countries: depend on biomass (fuelwood, charcoal) for heating/cooking – Can’t afford fossil fuels!!!! 93% Nonrenewable World’s largest energy user 5% of world’s population uses 25% of world’s energy World U.S.

What are fossil fuels??? Composed of partially decayed organism remains Form too slowly to replenish NOT sustainable Ex: Coal, Oil, Natural Gas

Fossil Fuels Oil, Natural Gas & Coal Oil and Natural Gas are less dense than coal – Move upward through porous rock and become trapped Developed countries (like US!) consume 8X MORE energy than developing countries

Formation of Fossil Fuels Formation of coal – Over time, plants die and get covered by water and sediment – Heat & pressure convert material into carbon rich ore (COAL) & sedimentary rock Formation of Oil – Death of plants/animals: go through decomposition – Heat & pressure convert material to hydrocarbons (OIL) without oxygen in sediments that prevent decay

Formation of Fossil Fuels Formation of Natural Gas – Same as oil, just produced at higher temperatures

2008: Energy Use in the US Comprised of – Oil 40% – Natural Gas 23% – Coal 20% – Nuclear Power 8% – Hydropower 3% – Biomass 3% – Geothermal, Solar & Wind 1%

We depend heavily on oil… You know it as: – Petroleum and crude oil Composed of various hydrocarbons Produced by decomposition of dead organic matter from plants/animals We import at least 52% of our oil

Oil Supplies Proven oil reserves – Identified deposits that can be extracted profitably with current technology Unproven reserves – Probable reserves: 50% chance of recovery – Possible reserves: 10-40% chance of recovery Proven and unproven reserves will be 80% depleted sometime between 2050 and countries have at least 60% of the world’s crude oil reserves Global oil production leveled off in 2005

Coal Solid fossil fuel Burned in power plants (inefficient) World’s most abundant fossil fuel Different steps of formation: – Peat: not a coal – Lignite: brown coal – Bituminous: soft coal – Anthracite: hard coal

Advantages and Disadvantages of Using Coal Advantages: – Plentiful – High net energy yield – Low cost Disadvantages: – Very high environmental impact – Severe air pollution Sulfur released as SO 2 Large amount of soot CO 2 Trace amount of Hg and radioactive materials

Natural Gas Mixture of gases 50-90% methane (Ch4) Versatile with high net energy – Heat space & water – Produce electricity More plentiful than oil Fairly low cost Issue of fracking (will examine in video)

Conventional Natural Gas VS Fracking Conventional Natural Gas – Lies above most reservoirs of crude oil – Makes US dependent upon unstable countries like Russia and Iran Fracking: – Official term: Hydraulic fracturing – Extraction from shale rocks using a combination of vertical and horizontal drilling – Water and other chemicals used to “fracture” rocks and release gas – Michigan sits on deposits of shale