Renewable Energy Sources: Untapped Potential
Hydraulic Power
Hydropower is generated by the falling mass of water to save a difference in level. Currently, it is used to generate electricity in power plants. Reservoirs and dams are associated to retain the water and create the necessary gap for the fall of the water.
Advantages
- Minimum maintenance cost.
- It does not pollute.
- Favors navigable rivers.
Disadvantages
- Geographical limitations.
- High cost.
- Sometimes it creates social conflicts.
Tidal Energy
It is based on the exploitation of tidal currents. To be productive, two conditions are needed:
- The difference in water level.
- The topography and shape of the coast should allow to build dams.
This is the enclosure of a bay by a dam with sluice gates. Turbines connected to an alternator are installed in them. When there is high tide, the water enters the enclosed area and generates energy, and when it falls back to the sea, it reactivates the turbines.
Advantages
- Clean.
Disadvantages
- Requires very precise locations that are difficult to locate.
Geothermal Energy
It is the energy from the heat stored in Earth’s interior. This is caused by the spontaneous disintegration. Natural and continuous monitoring of radioactive isotopes.
The heat reservoirs need to be in contact with water to be productive. When temperatures are low (50-90ºC), they are used for heating swimming pools and heaters. If the temperature exceeds 150ºC, they are used in the production of electricity.
Advantages
- Clean and cheap.
Disadvantages
- There needs to be groundwater.
- Its use must be in place and operating.
- The extraction of groundwater can cause land subsidence.
Biomass Energy
Biomass is all organic matter generated in the metabolic processes of living things, such as agricultural residues, livestock and forestry, industrial waste, like leftover food, or biofuel. In poor countries, it is still used.
Advantages
- They are less polluting than fossil fuels.
- Low cost.
- Favors the reduction of waste accumulation.
Disadvantages
- Requires complex technology.
- The transformation of biomass energy should be in the same spot where the raw material is obtained.
- Liquid biofuels are very corrosive and emit pollutants when burned, although having no sulfur, it does not contribute to acid rain.
Hydrogen
It is a very abundant element on Earth, although it is not found free but is part of water and other molecules. It is considered an eternal fuel. It is efficient because it produces three times more heat energy than gasoline. Currently, natural gas is obtained, and its production involves the consumption of fossil fuels and CO2 emissions into the atmosphere.
The ideal mechanism to obtain it is electrolysis, which consists of using a direct current to decompose water into hydrogen and oxygen. It is still very expensive. It is the breaking of the water molecule by light (photolysis).
Other ways of using hydrogen is through fuel cells. Batteries are not spent. At the cathode (pole -), the rupture of hydrogen occurs in H+ and electrons. They are guided through a circuit, causing electrical current. Hydrogen ions traverse the stack and are directed toward the anode (+ pole), where it reacts with oxygen, releasing water.