Electric Power and Energy Sources

Energy Sources for Power Generation

• Various energy sources include fossil fuels, nuclear reactions, wind, solar heating, and ocean tides.
• These sources generate motion energy for electrical power production through generators.

Electric Power

• Defined as the rate of electrical energy generation from other energy sources.
• Power also refers to the conversion rate of electric energy back into forms like light, heat, or sound.

Power Generation Steps

• Turbine: Energy from falling water spins the turbine, initiating power generation.
• Shaft: Rotating shaft transforms kinetic energy into electrical current via a powerful electromagnet within a wire coil.
• Step-Down Transformer: Reduces high voltage for safe transmission through smaller lines, making it suitable for residential use.

Power Plant Functionality

• Large generators utilize powerful electromagnets surrounded by extensive copper wire coils to convert motion into electrical energy.

Measurement of Power

• Watt (W): Standard unit for measuring power; indicates the rate of energy usage by electrical appliances.
• Kilowatt (KW): Equals 1,000 watts, representing a larger scale of power.

Power Formulas

• Electric Power Calculation: ( P = VI ) (Power = Voltage × Current).
• Rearranged formulas:
  • Voltage = Current / Electric Power
  • Current = Voltage / Electric Power

Energy Calculation

• Energy usage formula: ( E = PT ) (Energy = Power × Time).
• Rearranged versions:
  • Power = Time / Energy use
  • Time = Power / Energy use

Kilowatt-hour (KWH)

• Unit of measurement for energy consumption; represents the amount of energy used over one hour at a rate of one kilowatt.

Example Calculation

• For drying clothes in a 3KW dryer over 30 minutes:
  • Power = 3.0 KW, Time = 0.5 hr.
  • Plugging into the formula: ( E = 3.0 , \text{KW} \times 0.5 , \text{hr} = 1.5 , \text{KWh} ).
  • Confirmed unit consistency; final energy usage equals 1.5 KWh.