Renewable Energies- Renewable Energies must be different from clean energies or green energies. Clean or green energy is that which, during its production, generates fewer polluting elements and has a reduce environmental impact compare to other types of energy.

What are Renewable Energies?

Renewable energies are energy obtain sustainably from natural resources, such as the sun, wind, water, and organic matter.

These energy sources are consider inexhaustible because they are renewed faster than consume.

The name also knows renewable energies of alternative energies to differentiate them from conventional non-renewable energies.

Non-renewable energies are obtain from fossil fuels (coal, oil, gas) and nuclear (uranium, plutonium). These energy sources are limited and generate greenhouse gases and radioactive waste.

Types of Renewable Energies

 

Solar energy

Solar energy is obtain from sunlight, the most crucial inexhaustible source for the amount of energy it emits. Therefore, The sun originates most of the natural processes on Earth and influences the rest of renewable energies.

Within solar energy, we can find the following types:

  • Photovoltaic solar energy, obtained through solar panels, comprises photovoltaic cells connected. Photovoltaic cells are devices that transform solar radiation into electrical current. The electricity can be use directly, or it can be store in batteries and accumulators.
  • Concentrate solar energy is a system that concentrates solar radiation using mirrors to heat a fluid and produce steam with which turbines are activated that generate electricity.
  • Thermal solar energy harnesses the sun’s power through thermal solar panels. These panels concentrate the radiation to heat a fluid that transports the heat to a tank where the water is heated. This system can be use in both domestic and industrial installations.

Wind Power

Wind energy is the one obtain thanks to the force of the wind. The wind turns the blades of the wind turbines, activating the turbines that transform the movement into electrical energy. The energy produce can be store in batteries, accumulators, or turned over to the electrical network.

The higher the wind speed and the size of the wind turbine blades, the greater the amount of energy obtain.

Offshore wind farms produce up to twice as much energy as onshore facilities since the strongest and most constant winds originate in the high seas.

Hydroelectric power

Hydroelectric power is what transforms the movement of river currents into electricity.

The system is made up of a dam that retains the river’s flow by storing the water in a reservoir. The flow of water is channeled, taking advantage of its force to activate the turbines of the generator, which transform the kinetic energy into electrical current.

The electricity produce is store in accumulators and distribute by the electrical network.

Sea ​​Energy

The energy of the sea is produce by the movement of the masses of water in the seas and oceans, and we can find the following types:

  • Wave energy is the energy obtain thanks to the oscillation of the sea waves, which starts the turbines that drive the generators responsible for producing electricity.
  • Tidal energy, this type of energy is generate from the thrusting movement produce by seawater with the alternation of the tides.
  • Salinity gradient energy, this type of system generates electricity from the difference in salinity between the seawater and the water of the rivers at their mouths. Having different densities, both types of water exert pressure to generate energy.
  • Tidal, thermal energy is the energy generate from the differences in temperature between the waters of the ocean depths and the surface waters.

Biomass

Biomass is a matter of biological, animal, or vegetable origin, which can be use as a source of energy. In addition, it is renewable because it is generate cyclically and can be store and use later.

According to its origin, we can find the following types of biomass:

  • Natural biomass is generate without human intervention, such as plant remains or seaweed.
  • Residual biomass comes from organic waste generate by human activities such as agricultural, forestry, urban, or industrial waste.
  • Biomass from energy crops is biomass obtain from crops intend for energy production.

There are several biomass transformation processes through which we obtain different types of fuels:

Biogas gas generate by microorganisms’ decomposition of organic matter in an oxygen-free environment called anaerobic digestion. It is mainly compose of methane and carbon dioxide and is use in heating and transport system.

Liquid biofuels are obtain from the fermentation vegetable matter rich in oils and carbohydrates. In addition, crops such as corn, soy, or palm produce biodiesel and bio alcohols such as bioethanol.

Solid biofuels come from forest residues and the wood industry and generate thermal and electrical energy through combustion. The most use are firewood, chips, pellets, dried fruit shells, and olive pits.

Geothermal Energy

Moreover. It is the energy that originates from the heat coming from the Earth’s core. On its way up to the surface, this heat heats underground water masses and produces water vapor, giving rise to hot springs and geysers.

It is mainly use as an air conditioning and water heating system for sanitary purposes. However, it is also use to generate electricity in areas of more excellent tectonic activity and temperature.

Hydrogen Energy

This type of energy consists of using surplus renewable energy to obtain hydrogen, which can be store and use to produce more power at another time.

Two processes are use to obtain hydrogen:

  • Electrolysis is decomposing water molecules by electric current to obtain pure hydrogen.
  • Reform is a chemical process that transforms methane from biogas into hydrogen.

Above all, Hydrogen is store in tanks that keep it under high pressure. Hydrogen cells, which are similar to conventional batteries, use hydrogen as fuel to generate electrochemical energy for electricity.

These batteries are mainly use in electric vehicles, guaranteeing a transport most importantly system without emissions.

Advantages and Disadvantages of Renewable Energies

Advantage

  • The resources they come from are consider inexhaustible because they are periodically renew.
  • They do not generate greenhouse gas emissions.
  • Although the initial investment is high, it is compensate by the low maintenance cost and the security of its facilities.
  • It gives the possibility of having the energy to those who have never had access before.

Disadvantages

  • Large land or sea extensions are necessary to install the require systems.
  • Climatic and geographical conditions affect energy production.
  • However. Renewable energies do not meet the energy demand; we can both have surpluses and situations of energy shortages.
  • Renewable energy plants have an impact on the environment and the landscape.

Conclusion:

Energy from naturally renewing but flow-limit sources is refer to as renewable energy. Renewable resources have an almost infinite lifespan but have a finite amount of energy that can be extracted from them in a given amount of time. Biomass is one of the main types of renewable energy. Timber and wood waste.