Technology and Livelihood Education Basics: Electricity

Technology and Livelihood Education Basics: Electricity

Technology and Livelihood Education Basics: Electricity

By: Admin

Source: LET Reviewer Online Philippines Files posted by Mr. Cunanan

To save everyone from downloading the pdf files, we decided to post this very detailed notes on T.L.E discussing about Electricity.










  • From the Greek word ἤλεκτρον, (elektron), meaning amber, and
  • From New Latin ēlectricus, “amber-like”.
  • It is a general term that encompasses a variety of phenomena resulting from the presence and flow of electric charge.
  • A class of phenomena arising from the existence of charge.
  • A form of energy, caused by the behavior of electrons and protons
  • It is the flow of electrical power or charge
  • Is a basic part of nature and it is one of our most widely used forms of energy.
  • A fundamental entity of nature consisting of negative and positive kinds.
  • A property of certain fundamental particles of all matter, as electrons (negative charges) and protons or positrons (positive charges) that have a force field associated with them and that can be separated by the expenditure of energy: electrical charge can be generated by friction, induction, or chemical change and is manifested by an accumulation of electrons on an atom or body, constituting a negative charge, and a loss of electrons, constituting a corresponding positive charge
  • The potential difference (voltage) across an ideal conductor is proportional to the current through it.
  • Electricity is measured in units of power called watts.
  • It was named to honor James Watt, the inventor of the steam engine.



Relevant Terminologies:

  1. Electric charge
  • A property of some subatomic particles, which determines their electromagnetic interactions. Electrically charged matter is influenced by, and produces, electromagnetic fields.
  1. Electric current
  • A movement or flow of electrically charged particles, typically measured in amperes.
  • Describes a flow of electric charge. Electric current is either Direct Current (DC) a single-direction flow, or Alternating Current (AC) which describes a current that repeatedly changes direction.
  1. Electric field
  • An influence produced by an electric charge on other charges in its vicinity.
  1. Electrical energy
  • Is a form of energy present in an electric field or magnetic field, electrical energy is measured in joules?
  • It can be converted to work though the use of an electrical device or machine such as electric motor.
  1. Electric potential
  • The capacity of an electric field to do work, typically measured in volts.
  1. Electromagnetism
  • A fundamental interaction between the magnetic field and the presence and motion of an electric charge.
  1. Electric power
  • Is the name given to electrical energy production and distribution.




Biomass Energy

  • Biomass describes all solid material of animal or vegetable origin from which energy may be extracted it also called solid biomass.
  • Plant products (such as corn husks, branches, or peanut shells), waste paper, and cow dung are examples of biomass fuels.
  • Biomass can be heated, burned, fermented, or treated chemically to release energy.
  • Biomass is produced by photosynthesis; basic research in photosynthesis may provide systems that directly convert sunlight into fuels.
  • Biomass can also be used a fuel for space heating and factory processing, and to produce liquid transportation fuel such as ethanol

Advantages of Biomass Energy

  1. Renewable energy source
  2. Very low greenhouse gas emissions
  3. Can produce energy on-demand
  4. Energy is easily stored

Disadvantages of Biomass Energy

  1. Low energy return on investment
  2. High air pollution emissions
  3. Very high water and land requirements
  4. High occupational hazards


Geothermal Energy

  • Geo means earth and thermal means heat. Meaning geothermal energy is the heat energy of the earth.
  • Geothermal Energy can be harnessed from the Earth’s natural heat associated with active volcanoes or geologically young inactive volcanoes still giving off heat at depth.
  • Steam from high-temperature geothermal fluids can be used to drive turbines and generate electrical power, while lower temperature fluids provide hot water for space-heating purpose, heat for greenhouses and industrial uses, and hot or warm springs at resort spas.




  • The term hydro comes from an ancient Greek word for water
  • The force of moving water from rivers or storage reservoirs
  • The process starts with the annual hydrologic, or water cycle, providing seasonal rain and runoff from snow pack. The runoff from rain and snow collects in lakes, streams and rivers and flows to dams downstream. The water funnels through a dam, into a powerhouse and turns a large wheel called a turbine. The turbine turns a shaft that rotates a series of magnets past copper coils in a generator to create electricity. The water then returns to the river. From the powerhouse, transmission lines carry electricity to communities.


Advantages of Hydropower

  1. Very high return on energy investment
  2. Very low greenhouse gas emissions
  3. Very low air pollution emissions
  4. Inexpensive once dam is built
  5. Can produce energy on-demand
  6. Provide water storage and flood-control


Disadvantages of Hydropower

  1. Very high land requirements
  2. Extremely high impacts to land and water habitat
  3. Best sites are already developed or off-limits
  4. Disastrous impacts in case of dam failure










(Magat Dam located in Isabela, Philippines)


Ocean Power

Oceans have tremendous energy in the movement of their currents and waves.


Marine Currents

There are two kinds of marine currents: two-way (tidal) currents, and one-way currents.

  1. Two-way currents are the ocean tides, caused by gravitational pull of the moon and sun. Each heavenly body pulls on the part of the ocean nearest to it, causing bulges in water height. As the earth rotates, those bulges move in relation to the world‘s coastlines, pulling water onto and away from the shore. So the turning of the earth causes a moving pattern in the ocean: at every coast in turn, the level rises and falls, resulting in two high tides and two low tides daily.
  2. One-way currents are like massive ―rivers‖ of ocean water flowing within the ocean for hundreds — sometimes thousands — of miles.















(Sample equipment that generates electrical power through ocean currents)


Solar Energy

Solar Energy, provided by the sun is the most inexhaustible and cleanest source of energy known. Its heat and light arrive week in and week out – free. But not in uniform amounts each day, or in concentrated form, and not at all at night. Consequently, the barriers to greater use of solar energy by a world faced with dwindling energy resources are significant: mainly, diffusion and the inability economically to store solar energy, use it directly, or convert it to electricity.


Advantages of Solar Energy

  1. Renewable energy source
  2. Very low greenhouse gas emissions
  3. Very low air pollution emissions
  4. Very low water requirements
  5. Modular, low-profile, low-maintenance
  6. Very safe for workers and public


Disadvantages of Solar Energy

  1. Intermittent energy source
  2. High land requirements
  3. Expensive
  4. Manufacture involves some toxic materials











(solar power farm)


Wind Power

  • Wind power is a renewable resource. Wind is a form of solar energy.
  • The basic machinery that converts wind power to electricity is called a wind turbine. The force of the wind spins blades attached to a hub that turns as the blades turn. Together, the blades and hub are called the rotor. The turning rotor spins a generator, producing electricity.
  • Mankind has been making use of wind power for centuries. One of the first known uses was to propel sailing ships. This was followed, centuries later, by the development of windmills.


Advantages of Wind Power

  1. Renewable energy source
  2. Very low greenhouse gas emissions
  3. Very low air pollution emissions
  4. Very low water requirements
  5. Very safe for workers and public


Disadvantage of Wind Power

  1. Limited to windy areas
  2. Potentially high hazard to birds
  3. Moderate land requirements
  4. Intermittent energy source











(Bangui wind farm, Ilocos)


Coal Energy

  • Coal is a rock that burns as it releases energy. It is mostly made of the chemical element carbon.
  • Some coal is brown and crumbly, and some coal is hard, black, and glossy.
  • The greater the percentage of the coal that is carbon, the higher its rank or potential energy.
  • Coal is among the fossil fuels along with oil (petroleum), and natural gas. The fossil fuels are considered non-renewable energy resources.


Advantages of Coal Energy

  1. Inexpensive
  2. Abundant
  3. Low land requirements
  4. Can produce energy on-demand


Disadvantages of Coal Energy

  1. Non-renewable energy source
  2. Very high greenhouse gas emissions
  3. Very high air pollution emissions
  4. High land/water impacts from acid rain, mine drainage
  5. Highly hazardous occupation












(Masinloc Power Plant, Zambales)


Nuclear Energy

  • Nuclear energy is the energy trapped inside atoms, those tiny particles from which all matter is made.
  • The principle of producing electricity by heat is the same in nuclear power production as in coal or oil based energy production. By heat, the water is boiled to high pressure steam. The steam rotates the turbine. The generator attached to the turbine generates electricity. In a nuclear power plant the heat needed for producing electricity is generated in a nuclear reactor by the fission of atomic nuclei.
  • In the energy production, nuclear energy replaces fossil fuels, mainly coal, which poses significant environmental hazards. Of the new energy forms, nuclear power is so far the only one ready for large-scale energy production.
  • Nuclear power is economical and the annual fuel reserve of a nuclear power plant can be transported in just a few truck loads.


Advantages of Nuclear Energy

  1. Low greenhouse gas emissions
  2. Low air pollution emissions
  3. Low land requirements for power plants (though not for waste storage)
  4. Can produce energy on-demand


Disadvantages of Nuclear Energy

  1. Non-renewable energy source
  2. High water requirements
  3. Relatively expensive
  4. Waste remains dangerous for thousands of years
  5. Serious accident would be disastrous










Natural Gas

  • Natural Gas is made up mostly of methane.
  • Methane, a combination of hydrogen and carbon, is formed when plants and animals (organic matter) are trapped beneath the sedimentary layers of the earth.

Advantages of Natural Gas

  1. Inexpensive
  2. Low land requirements
  3. Can produce energy on-demand
  4. Relatively safe for workers and public

Disadvantages of Natural Gas

  1. Non-renewable energy source
  2. High greenhouse gas emissions
  3. Relatively moderate air pollution emissions
  4. Danger of explosion if handled improperly











We hope that our visuals helped in understanding more on the sources of electricity / electrical energy / electrical power!


Kindly anticipate our next set of articles on T.L.E!



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