Announcements – Nov. 1, 2006

Energy Sources I – Fossil Fuels

Lecture Objectives:

1) Trace the history of energy consumption in human populations and understand the current factors affecting energy consumption

2) Learn how fossil fuels are extracted and used

3) Explore the debate over drilling in ANWR

What is energy?

Energy – the ability to do work

Work is done when an object is moved over a distance

*Happens even at the molecular level

Everything we do requires energy in some form

Original source of energy for Earth is the Sun

• Producers convert sunlight to biomass

• 90% of useful energy lost as heat from one trophic level to the next

• Some energy always lost whenever it is converted between forms (2nd law…)

Brief history of human energy consumption

• Early humans like other animals in trophic pyramid – all work done by human muscle

• 1st alternative energy sources:

– domesticated animals

– burning biomass

Brief history of human energy consumption

• Wood & muscle primary sources of energy until relatively recently – still are in parts of the world

• Build up of population densities & permanent residences lead to local wood shortages – – switch to dung, other burnable biomass– where available, switch to coal & other

fossil fuels

World sources of energy 1850-2000

Industrial Revolution

• Machines replaced human and animal labor in the manufacture and transportation of goods.

• Steam engines converting heat energy into forward motion was central to this transformation.

Industrial Revolution• Fuel for machines first wood, then quickly switched

to coal

• Machines greatly increased work productivity– manufacturing, food production, transportation, etc.

• Countries/regions without large coal deposits were left behind in the Industrial Revolution

Switch from coal to oil

• Expanding factories needed larger labor pools, people began congregating around factories and cities.

• Widespread use of coal in cities led to increased levels of air pollution.

• Cleaner-burning oil and the internal combustion engine lead to decreasing dependence on coal in first half of 1900’s

Energy and Economics

• Direct link between economic growth and availability of inexpensive energy

• To keep energy prices down, many governments subsidize energy prices

– Artificially low prices encourages high rates of consumption & economic growth

• WWII spurred need for manufacturing & transportation, and increased consumerism

Keys to increasing energy consumption

1. Economic growth, convenience & energy consumption in positive feedback cycle

2. Government control of energy prices can encourage or discourage consumption

3. Energy consumption behavior of most people motivated by economics & convenience rather than by desire to use energy resources wisely

Comparison of U.S. and Europe

Price of gasoline determined by:

1. Purchasing & processing crude oil

2. Taxes

U.S. – taxes low, encourages automobile industry, diffuse population density

Europe – taxes high, encourages mass transit, city living

Transportation energy use per capita (gigajoules)

U.S. 105

Denmark 41

Netherlands 41

Review

• Switch from wood & muscle to fossil fuels and machines radically changed human lifestyles

• Our economic prosperity and way of life is utterly dependent on cheap energy

Where does this energy come from, and will it remain inexpensive?

Energy Sources

Non-Renewable Energy — Energy sources used faster than can be replenished.

*Coal *Oil *Natural Gas

Renewable Energy — Continuously present as a feature of the environment.

*Solar*Wind*Tides

Resources and Reserves

Resource — Naturally occurring substance of use to humans

Reserve — Amount of a known deposit that can be economically extracted using current technology.

Reserve levels change as technology advances, new discoveries are made, and profit margins change.

Fossil Fuel Formation -- Coal

300 MYA plant material began collecting underwater & decayed, forming a spongy mass called peat

Over time, peat became buried

Pressure and heat over time transformed peat into coal

Coal is our most abundant fossil fuel.

US has a 250 yr. supply

Primarily used for generating electricity.

Overburden

Vein

Two main extraction methods for coal:

1) Surface Mining (Strip mining)

Removing overburden on top of a vein.

Efficient but destructive.

2) Underground Mining

Minimizes surface disturbance, but costly and dangerous:

Two main extraction methods for coal:

Miners can become trapped

Toxic gas -Canary in the Coal Mine

Black Lung Disease

2002

How is electricity generated from coal?

Coal is burned to heat water to make steam

High pressure steam turns the turbines

The turbine spins the generator, which produces an electrical current

 

                                                                                         

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Environmental Impacts of Coal

Burning releases pollutants

Mining destroys habitat

Mining creates dust pollution

Oil and Natural Gas

Accumulations of dead marine organisms on the ocean floor were covered by sediments.

High pressure and temperature converted them into energy-rich compounds

Oil Use

Can be more concentrated than coal, burns cleaner (but not cleanly), and is easily transported through pipelines.

*Ideal for automobile use.

*Can be difficult to extract.

*Environmental damage due to oil spills

Crude oil can generate multiple products from a single barrel.

Natural Gas Use

Drilling requirements similar to oil.

Current primary use in the US is for heating

Natural Gas Use

Least environmentally damaging of fossil fuels.– Almost no air pollution.

Use is increasing (45% from 1985-2000).

World Oil Reserves

Natural Gas Reserves

What determines the price of oil and natural gas?

• Cost of extraction, production, transportation• Supply/demand & market forces• World politics

Oil heads back toward $63 as barrel October 26, 2006

Oil prices extended a sharp rally to within reach of $62 a barrel on Thursday, staying at their highest in nearly a month after a steep fall in U.S. crude oil inventories and more signs that OPEC is committed to cuts.

OPEC

Organization of Petroleum Exporting CountriesSaudi Arabia, Kuwait, Libya, Algeria, Iraq, Qatar, United Arab Emirates, Iran, Indonesia, Nigeria, Gabon, Venezuela

Controls over 75% of world’s known oil reserves (Middle Eastern countries have 45%)

Currently produces 41% of world’s crude oil and exports 55% of all traded oil.

Internal conflicts have lead to decreases in OPEC’s power in recent years

In 2000, the United States consumed an average of 19.5 million barrels of oil every day.

Oil consumption is expected to rise to 25.8 million bpd by 2020

We currently import about half our oil, that amount is expected to increase

How can we reduce our dependence on foreign oil?

One suggestion:

Increase our own oil production from our known reserves

CNNAlaska oil drilling back on agendaNovember 10, 2004 WASHINGTON (AP)

Republican gains in the Senate could give President Bush his best chance yet to achieve his No. 1 energy priority -- opening an oil-rich but environmentally sensitive Alaska wildlife refuge to drilling. "With oil trading at nearly $50 a barrel, the case for ANWR is more compelling than ever”. Bush is also expected in his second term to renew his call for action by Congress on a broader, largely pro-production, energy agenda -- from easing rules for oil and gas drilling on federal land in the Rocky Mountains to expanding clean-coal technology and improving the reliability of the electricity grid.

ANWR – To drill or not to drill?

Arctic National Wildlife Refuge

Points to know1. What were the main sources of human energy prior to 1850? After 1850?

2. How did the Industrial Revolution change human life and energy consumption? What was responsible for the shift from coal to oil?

3. What is the relationship between energy and economics? Why does energy consumption continue to increase in developed countries?

4. What is the difference between a resource and a reserve?

5. What is coal? How is it extracted and turned into usable energy? What environmental problems are associated with it?

6. How are oil and natural gas formed & extracted? What environmental problems are associated with them?

7.What determines the price of oil and natural gas? What is OPEC and why do we have to be interested in it?