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Energy/Electrical 2014-2015

Electrical Power Grids
Example of a path of electricity from a power plantto an appliance in a home—
1. power plant with generator
2. step up transformer
3. transmission lines (pylons)
4. step down transformer @ substation in the neighborhood
5. distribution lines (down streets)
6. step down transformer (bucket on pole or underground box)
7. circuit breaker
8. junction box
9. outlet
10. TV
power grids-----
  • system of wires, transformers, and other devices that carry electric current from power plants to individual users
  • A grid changes the voltage of the current it carries.
  • use alternating current (AC) in transmission and distribution systems---the voltage can be changed in an alternating current system to transfer energy more efficiently
  • When a business or home uses a wind turbine or solar panels, the extra energy that is created and not being used by the home or business will go out to the rest of the grid to be used by other people.

term / definition or information / examples
power plants / produce electrical energy from fossil fuels (coal), hydroelectric (water), geothermal power, or nuclear power /
generators
(in the power plant) / machine that changes mechanical energy (moving) into electrical energy (water heated to produce steam; steam turns turbine that spins the generator) /
step-up transformer
(outside power plant) / increases voltage
makes it easier to transport the electricity over long distances /
transmission lines /
  • transports high voltage long distances
  • carry electric energy from one point to another in the power system
  • metal pylons hold the large wires
/
substation /
  • located near to the end-users (in neighborhoods)
  • lowers voltage levels for use by end-users (industrial, commercial, and residential customers)
  • substations are made of step-down transformers
/
distribution lines
(down streets) /
  • smaller lines that carry electricity from substations to and throughout neighborhoods
  • underground or on overhead poles
/
step-down transformer / decreases voltage
/

meter / measures the amount ofelectric energyconsumed by aresidence,business, or an electrically powered device /
circuit breaker / designed to protect anelectrical circuitfrom damage caused byoverloadorshort circuit /
junction box /
  • box (either plastic or metal) used by electricians to join wires together
  • hidden in walls/ceilings
/
outlets /
  • U.S. outlets transmit a charge of 120 volts (AC)
  • AC direction reverses cyclically
  • more efficient to prevent the loss of excess energy
  • electricity passes through hot socket, into hot side of appliance's plug, into appliance, out through appliance’s plug, back into neutral socket
/
Mississippi Companies
power plants /
  • Grand Gulf Nuclear Power Plant (Port Gibson)
  • Mississippi Power electric plant (Gulfport)--coal
/
businesses /
  • Kuhlman Electric Corporation (CrystalSprings)— major supplier of the transformers for the Mississippi power grid
  • Howard Industries (Laurel and Ellisville)—supplies electrical equipment for the grid
/
Energy Sources
fossil fuels /
  • remains of ancient organisms
  • coal, oil, natural gas
  • nonrenewable
  • combustion----burning of fossil fuels which returns CO2 to atmosphere
  • acid rain
/
nuclear /
  • energy stored in the nucleus of an atom
  • energy released when nuclei join together or split apart
  • ¼ of Mississippi’s electricity---nonrenewable
/
hydroelectric /
  • energy of moving water
  • renewable
/
geothermal /
  • heat energy obtained from below the Earth’s surface
  • renewable
/
wind /
  • harnessing the wind to produce electricity through windmills
  • turbines
  • wind farms
  • renewable
/
solar /
  • radiation energy produced by the sun
  • more reaches the equatorial regions rather than the polar regions because those regions receive sun rays closest to vertical
  • renewable
/
Global Warming---
Theory of Global Warming or Climate Change /
  • increase in average temperatures
  • much of the sunlight is reflected into the atmosphere as heat
  • some gases in atmosphere absorb reflected heat which some scientists think increase average temperatures
Possible Effects----
  • rising temps will cause the melting of polar ice caps, sea ice, glaciers
  • increase ocean levels and flood large cities
  • may alter areas of fertile land into deserts
  • threaten wildlife, habitats, crops and entire ecosystems
/
greenhouse effect /
  • trapping heat by certain gasses in the atmosphere
  • holding heat near Earth (acts like a greenhouse)
  • natural effect of Earth’s atmosphere
  • makes Earth warm enough to support life
/
greenhouse gases /
  • N2O--- fertilizers release nitrous oxide into the environment; factories; burn fossil fuels
  • CH4---dig for or transport fossil fuels; cattle and other livestock release methane as they digest food; released by landfills as organic matter decays
  • CO2---combustion of fossil fuels
/
  • water vapor (H2O)
  • carbon dioxide (CO2)
  • methane (CH4)
  • nitrous oxide (N2O)