Transcript Unit D Section 4.0 - Calgary Christian School

Unit D Section 4.0
The use of electrical energy affects society and the
environment
4.1 – Electricity Sources and Alternatives
• About 65% of the world’s energy comes
from fossil fuels
• Fossil fuels are formed from dead plants
and animals; coal, oil, and natural gas
Producing Electricity from Heat
• Fossil fuel power and nuclear power
both produce heat that is used to
make steam
• This high-pressure steam then turns a
turbine
• The turbine then turns a generator,
which produces electrical energy
A Coal-Fired Power Plant
Nuclear Fission
• Nuclear Fission: is the splitting of atoms,
which transforms them into lighter
elements and releases large amounts
of energy
Other Sources of Heat Energy
• Geothermal energy is energy
produced by the Earth itself
• Geysers, hot springs and thermal vents
are all sources of geothermal energy
Cogeneration
• Cogeneration: use of waste energy
from a process for another purpose,
such as heating or generating
electricity
Hydroelectricity
• 20% of the world’s electricity comes
from hydroelectricity
• The force of falling water turns turbines,
which in turn operate the generators
Renewable vs Non-Renewable Energy
• Renewable Energy: resource such as
water or wind energy that is
continually replenished and therefore
can be used indefinitely
• Non-Renewable Energy: a resource,
such as coal or natural gas, that
cannot be replenished
Alternative Energy Sources
• Tides
• Wind
• Sunlight
• Fuel Cells
4.2 Electricity and the Environment
• Fly Ash: fine airborne ash produced by
burning coal or other solid fuels
• fly ash contains small amounts of mercury,
a poisonous metal that can damage the
nervous system.
Sustainability
• If energy is conserved, then less energy
is required
• This puts less of a strain on energy
sources
• As well, a greater demand for fuels
and energy drives up prices
• Therefore, conservation not only
reduces environmental impacts, but it
also reduces energy demands and the
price of energy
Sustainability
• Ultimately, we should hope achieve
sustainable energy use
• (use of resources at a rate that can be
maintained indefinitely without
depleting the resources or harming the
environment)
• This may involve making compromises
regarding how we use energy in the
future
4.3 – Electrical Technology and Society
• Electrical communication originated in
1844 when Samuel Morse sent the first
telegraph message
• Since then, electrical technologies
have continually developed and
evolved to meet the needs of our
society
Benefits of Electrical Technologies
• Speed and convenience
Drawbacks of Electrical Technologies
• Makes sustainability difficult
• Increase in solid waste materials
• Expensive for developing countries to
adopt
Computers and Information
• Computers have changed since the
unveiling of ENIAC in 1946
• Now, modern computer chips 0.5 mm
square have the same computing
power as the room-sized ENIAC
• Computers use Binary numbers (zeroes
and ones) that correspond with the on
and off states of the millions of tiny
transistors in microcircuits
Electricity and Computers
• Computers use several ways to store
information
• CDs and DVDs have tiny pits on their
surface
• When a laser runs over the pits, it
produces a digital signal which the
computer then decodes
• Hard drives use pulses of electricity to
encode information onto a magnetic
disk which rotates at speed up to
300 km/h
• The magnetized sections of the disc
are read by the computer, which
produces a digital signal which is
decoded by the computer
Electrical Transmission of Information
• Digital data can easily be transmitted
and shared due to advances in
technology such as wireless
technology and the internet
• However, these developments have a
number of major drawbacks:
Privacy and Security
• Identity Theft:
• Private Information:
Validity of Information
• Information Sources:
• Propaganda:
Information Overload
• Searching for Information: