ENERGY CONCEPTS

FORM

S O

F EN

ERG

YForm Description

Mechanical 2 types: potential and kinetic

Thermal Heat is the internal energy in substances- the vibration

and movement of the atoms and molecules within

substances

Chemical Stored in bonds between atoms in a molecule

Electrical Results from the motion of electrons

Nuclear Stored in the nuclei of atoms: it is released by either

splitting or joining atoms

Electromagnetic Travels by waves

PO

WER

AN

D U

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S

Unit or Prefix Description

BTU (British Thermal Unit)

Unit of energy used in the US.

Joule is used in other countries.

Definition: the amount of heat required to raise the

temperature of 1 pound of water by 1oF

Horsepower Used in the automobile industry

1HP=746watts

Kilo- 1000 = 103

Mega- 1,000,000 = 106

Watt (electrical) Kilowatt-hour (kWh)= amount of energy expended by

a 1 kilowatt device over an hour. Used by power plants

and home energy bills

Watt (thermal) Nuclear power plants produce heat measured in

thermal watts

REVIEW: SCIENTIFIC NOTATION

•The coefficient must be greater than or equal to 1 and

less than 10

•The base must be 10

•The exponent must be a whole number

•Positive whole number indicates the amount of places the

decimal in the coefficient moves to the right

•Negative whole numbers indicate the amount of placed

the decimal in the coefficient moves to the left

REVIEW: SCIENTIFIC NOTATION CONT.

•Multiplying: multiply the coefficients and add the

exponents, base will remain 10

•Dividing: divide the coefficients and subtract the

exponents, the base will remain 10

•Adding or Subtracting: express the numbers as the same

power of 10, then add or subtract the resulting coefficients

ENERGY CONVERSIONS

• Middleton is a rural community with a population of 8000 homes. It gets its

electricity from a small, municipal coal-burning power plant just outside of town. The

power plants capacity is rated as a 20 megawatt output with the average home

consuming 10,000 kilowatt hours (kWh) of electricity per year. Residents of

Middleton pay the utility $0.12 per kWh.

• 1) The existing power plant funs 8000 hours per year. How many kWh of electricity

is the current plan capable of producing?

• 2) How many kWh of electricity do the residents of Middleton consume in one year?

• 3) How much does an average customer pay for electricity from the municipal coal-

burning plant?

LAWS OF THERMODYNAMICS

1ST LAW: CONSERVATION OF ENERGY

•Energy can not be

created or destroyed, it

can only change from

one form to another.

2ND LAW: ENTROPY

•Energy is converted from one

form to another, a less useful

form results-

•Example: only 20% of chemical

energy from gasoline is

converted to mechanical, the

rest is lost to the surroundings as

heat

ENERGY CONSUMPTION

•Nonrenewable Energy: supplies are limited

•Coal, petroleum, natural gas, propane,

uranium

•Renewable energy: replenished in a short

period of time

•Biomass, geothermal, hydropower, solar

energy, wind power

HISTORICAL CONSUMPTION OF ENERGY

•Pre-Industrial Revolution: wood

•Industrial Revolution: coal

•Middle of 20th Century: Petroleum

•Late 20th Century: Natural Gas and Coal

•Up until the 1950’s the United States was self

sufficient in energy production and consumption

•When consumption outpaced domestic production,

oil needed to be imported: Oil Crisis of 1973

•Beginning in 1998, net imports of oil surpassed the

domestic oil supply in the U.S.

OIL CRISIS OF 1973

UNITED STATES WAS UNABLE TO

PROVIDE ENOUGH PETROLEUM

PRODUCTS FOR CUSTOMERS.

IMPORTS OF PETROLEUM WERE

NEEDED TO MEET THE DEMAND.

•Industry is the

highest consumer

of electricity,

followed by

transportation,

residential, and

commercial

FUTURE ENERGY NEEDS

COAL

•Clean Coal Technology

•Processes that reduce negative environmental

effects of burning coal

•Washing the coal to remove minerals and impurities

•Capturing the sulfur dioxide and carbon dioxide

from the fuel gases

METHANE HYDRATES

•Methane locked in ice formed at low

temperature and pressure

•Found on land in permafrost regions and

beneath ocean floor

•3000x more than is found in the atmosphere

•Thought to be enough energy to supply for

hundreds to thousands of years

NATURAL GAS

•Greater role in power generation

•Expanded use for transportation fuel

•Future use of alternative liquid fuel and

hydrogen for fuel cells

•Primary waste produce is CO2

FUTURE ENERGY CRISIS

•Price of energy is driven by the principle of supply and

demand

•Oil supply is controlled by OPEC (organization of petroleum

exporting countries- such as Saudi Arabia and Venezuela)

•Most of the world’s energy is supplied by burning oil

•At current rate of consumption world oil reserves are

predicted to last 50 years

•As supplies decrease prices will increase

•Other sources of energy will become more economical