Clean Energy: Sustainable Power from Natural Resources

Tidal Power

Tidal energy is produced by the movement of water masses caused by rising and falling tides and the waves that originate on the sea surface due to wind action.

Benefits:

• It is a clean energy source.
• No waste.
• Almost inexhaustible.

Disadvantages:

• They can only be in sea areas.
• May be affected by weather disasters.
• Depends on the tidal ranges.
• Facilities are large and expensive.

Hydraulic Power

Hydropower is produced by the water retained in dams and reservoirs at high altitudes (which has gravitational potential energy). If at one point dropped to a lower level, this energy is converted into kinetic energy and then into electricity in a hydroelectric power station.

Advantages:

• It is a source of clean energy.
• No waste.
• Easy to store.
• The water stored in reservoirs located in high places can regulate the river flow.

Cons:

• The construction of hydroelectric power stations is expensive and requires large power lines.
• Reservoirs cause losses of productive land and land animals due to flooding.
• They also cause the decrease of the flow of rivers and streams below the dam and alter water quality.

Wind Energy

Wind energy is the kinetic energy produced by wind. It is transformed into electricity in devices called wind turbines (special windmills).

Advantages:

• An inexhaustible energy source, and once installed, free.
• Non-polluting: the absence of combustion produces no acid rain, does not increase the greenhouse effect, does not destroy the ozone layer, and does not generate waste.

Disadvantages:

• It is an intermittent power source since it depends on the regularity of the winds.
• Wind turbines are large and expensive.

Solar Energy

Solar energy reaches the Earth in the form of electromagnetic radiation (light, heat, and ultraviolet rays in particular) from the Sun, which has been generated by a nuclear fusion process. The use of solar energy can be done in two ways: by high-temperature thermal conversion (photothermal system) and photovoltaic conversion (PV system).

High-temperature thermal conversion transforms solar energy into heat energy stored in a fluid. To heat the liquid, devices called collectors are used.

Photovoltaic conversion is the direct conversion of light energy into electrical energy. It uses solar photovoltaic cells (silicon or germanium).

Advantages:

• A clean energy source.
• Provides cheap energy in non-industrialized countries.

Disadvantages:

• It is an intermittent energy source since it depends on the weather and the number of hours of sunshine per year.
• Its energy efficiency is quite low.

Biomass Energy

Biomass energy is obtained from organic compounds by natural processes. The term biomass refers to solar energy, converted into organic matter by vegetation, that can be recovered by direct combustion or by converting the material into other fuels such as alcohol, methanol, and oil. Biogas can also be obtained, of similar composition to natural gas, from organic waste.

Advantages:

• It is a source of clean energy.
• Low waste, which is also biodegradable.
• Occurs continuously as a result of human activity.

Disadvantages:

• You need lots of plants and, therefore, lots of land.
• It tries to "make" the right plant through genetic engineering.
• Its performance is lower than that of fossil fuels.
• Produces gases such as carbon dioxide, which increase the greenhouse effect.