Post on 27-Feb-2021
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
NIT
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