Question

Which two types of energy are collected under the title of marine energy?

Short answer

Wave energy and tidal energy are the two types collected under marine energy.

Step-by-step solution

Identify Marine Energy Sources

Marine energy refers to energy obtained from oceanic sources. The main types of energy harnessed from marine sources include wave energy and tidal energy. These sources capitalize on the natural movements within ocean waters to generate power.

Understand Wave Energy

Wave energy is derived from the surface motion of the sea. The kinetic energy generated by wind-driven waves gets transformed into power using various conversion technologies that capture the up-and-down motion.

Understand Tidal Energy

Tidal energy is harnessed from the gravitational pull of the moon and sun and the rotation of the Earth, causing rising and falling tides. Tidal power plants typically exploit the potential energy from the height difference between high and low tides using turbines and generators.

Key concepts

Wave Energy

Wave energy is a type of marine energy that harnesses the natural power of ocean waves. This energy is generated when the wind blows over the surface of the sea, creating waves. These waves carry kinetic energy, which can be captured and converted into electricity using wave energy conversion technologies.
Wave energy converters are devices specifically designed to harness this up-and-down motion of waves. These can include buoys or floating platforms that move with the waves, capturing the energy generated.
Using wave energy has several benefits:

• It's a renewable energy source, meaning it won’t run out.
• It has a minimal environmental impact, offering a cleaner alternative to fossil fuels.
• Wave energy is consistently available and more predictable than solar or wind power.

Although promising, wave energy technology is still developing, and researchers are working to make it more efficient and cost-effective for wider use.

Tidal Energy

Tidal energy is another form of marine energy derived from the natural motion of ocean tides. This type of energy is created by the gravitational interactions between the Earth, the moon, and the sun. These interactions cause the regular rise and fall of ocean tides, which can be exploited to generate power.
Tidal power plants often harness this energy using tidal turbines or barrages. Tidal turbines work similarly to underwater wind turbines, capturing energy from the flowing water as the tide moves in and out. Barrages, on the other hand, utilize the potential energy created by the difference in water levels between high and low tides, capturing it with turbines installed in a dam-like structure.
Tidal energy presents several advantages, including:

• Its predictability, as tides are more regular and predictable than other renewable sources.
• Low maintenance costs due to the simplicity of most tidal technology.
• The potential to generate a significant amount of energy if implemented at suitable locations.

However, the initial costs and potential impacts on marine environments are challenges that need to be addressed as technology advances.

Energy Conversion Technologies

Energy conversion technologies are crucial for turning marine energy into usable electricity. These technologies play a vital role in harnessing both wave and tidal energy efficiently.
For wave energy, conversion technologies primarily involve capturing the motion of the waves. This can be achieved using devices like oscillating water columns, which utilize air turbines driven by the oscillating motion of the waves. Other devices may include point absorbers, which are floaters that move up and down with the wave motion, driving hydraulic pumps to generate electricity.
Tidal energy conversion technologies mainly include tidal stream generators and tidal barrages. Tidal stream generators resemble underwater wind turbines and are positioned where strong tidal currents are present. Tidal barrages, which function like dams, capture the potential energy from the height difference of tidal ranges.
The development of efficient energy conversion technologies is essential to maximize the potential of marine energy. Continuous innovation and research help enhance these technologies to make marine energy a more viable and competitive option in the renewable energy landscape.