Harnessing Renewable Energy: Eolian and Tidal Power Explained

EOLIC ENERGY

1. How It Is Obtained and Its Characteristics

• It is obtained from the wind's kinetic energy.
• The sun heats the Earth's air unevenly. The temperature differences in different locations cause air masses to move.

Characteristics of Wind:

• Speed: Higher wind speed results in greater power generation.
• Permanent Wind Zones: Areas with consistent wind patterns are ideal for wind energy production.
• Elevation: Wind speeds are typically higher at higher elevations.
• Power Density: Measured in watts per square meter (W/m²).

2. Parts of a Wind Power Plant

• Propeller (Blades):
  • Number of blades varies depending on the motor (typically one to six).
  • Made from lightweight materials like carbon fiber.
  • Spin the shaft, which drives the generator.
  • Types: Horizontal-axis (more common) and vertical-axis.
• Aerogenerator (Generator):
  • Located near the propeller.
  • Transforms kinetic energy from the rotating blades into electrical energy.
  • Some aerogenerators have microprocessors to control blade orientation for optimal performance.
• Tower:
  • Supports the propeller and aerogenerator.
  • Typically constructed from steel to withstand vibrations and provide structural integrity.

To connect to the electrical grid, the generated electricity must have a frequency of 50Hz. A regulator controls the turbine's speed to maintain a constant rotation rate and ensure consistent frequency output.

TIDAL ENERGY

1. Definition & Parts

Tidal energy is a form of hydropower that harnesses the energy from tides to generate electricity. It requires a significant difference between high and low tide levels (ideally 5 meters or more). Tides are more predictable than wind or solar resources.

Parts of a Tidal Power Plant:

• Dam: Prevents water from escaping the reservoir.
• Tidal Barrage: Separates the water reservoir from the open sea.
• Gates: Opened and closed to control the flow of water and initiate electricity generation.
• Turbine: Converts the potential energy of water into rotational kinetic energy.
• Generator: Transforms the mechanical energy from the turbine into electrical energy.
• Transformer: Increases the voltage of the generated electricity for efficient distribution.

2. Process of Tidal Power Generation

1. Rising Tide: As the tide rises, seawater flows into the reservoir, turning the turbine and generator to produce electricity.
2. High Tide: At the peak of high tide, the turbine may act as a pump to further fill the reservoir.
3. Falling Tide: As the tide recedes, water flows back out to sea, again driving the turbine and generator to produce electricity.
4. Low Tide: At the lowest point of low tide, the turbines may operate as pumps to empty the reservoir, preparing for the next tidal cycle.