
Renewable energies: what are they and what are they for?
Hydraulic, wind, solar, biomass and geothermal energy are clean and inexhaustible energies. As renewable energies, they play a fundamental role in the energy transition. Therefore, it is essential to promote their development to combat climate change.
An energy is said to be renewable when its energy source is based on use of inexhaustible natural resources, such as the sun, wind, water or biomass. The renewable energies, (renewable energy in English), are characterized by do not use fossil fuelsbut natural resources capable of unlimited renewal.
In addition to being inexhaustible energies, do not produce greenhouse gases (GHG), the main causes of climate change, as well as other polluting emissions, so they have a very low environmental impact. It can be said that renewable energies are clean energy sources.
A clean and renewable energy is named green energy. But it is important to know that not all clean energy is renewable, such as nuclear energy.
Why is nuclear energy not renewable?Nuclear power is one decarbonized and non-polluting energy. Does not emit gases greenhouse effect to the atmosphere. However the uranium, the fuel used in nuclear reactors, is a limited resource. Therefore, nuclear energy is clean but non-renewable energy.
Like non-renewable energy, renewable energy can produce electricity, heat, gas and fuel (called biogas and biofuel) without emitting greenhouse gases.
Advantages and disadvantages of renewable energies
The main advantage of renewable energies is their cleanliness, they do not generate an impact on the environment. But, they have many more advantages!
For consumers who want to hire this type of supply, it is also important to know its drawbacks.
Advantages and disadvantages of renewable energies
Advantages of renewable energies | Disadvantages of renewable energies |
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Renewable energies and non-renewable energies
Non-renewable energy is the energy produced by the fossil fuel combustion. Although the reserves of these fuels are enormous, they are in limited quantities.
What are non-renewable energies and what are they?Renewable energies are more sustainable alternative energies to non-renewable energies, such as Coalthe Petroleum and its derivatives.

At the current rate of global consumption, fossil resources are running out. It remains approximately:
- 50 years for the Petroleum;
- 60 years for the natural gas;
- 100 years for the uranium;
- 110 years for the Coal.
Fossil fuels are main cause of CO2 emissions in Spain. Therefore, it is imperative to reduce our dependence on fossil fuels and thus limit our greenhouse gas emissions. Support for the development of renewable energies is essential in this context.
Renewable energies: what types exist?
There are several types of renewable energy: solar energythe wind powerthe hydroelectric powerthe geothermal energy and the bioenergy.
Types of renewable energies
Renewable energy | Source | Technologies | Applications |
---|---|---|---|
Solar energy | Sun | Photovoltaic, solar thermal | Electricity, heating, cooling |
Wind power | Wind | Wind turbines | Electricity |
Hydroelectric power | Water | hydroelectric plants | Electricity |
Geothermal energy | land | Surface geothermal systems and heat pumps | Electricity, heating and cooling |
bioenergy | biomass | Biomass combustion, biogas plants, biofuels | Electricity, heating and cooling, transportation |
Solar energy

The solar energy It is a renewable energy obtained from the electromagnetic radiation from the sun. It is a renewable energy because it is obtained from a natural and inexhaustible source. However, such energy is not continuously available. It is an intermittent power source that relies on sunlight.
There are two types of solar energy:
- The Photovoltaic Solar Energywhich corresponds to the electricity produced by photovoltaic solar installations;
- The Thermal solar energywhich corresponds to the heat generated by the solar collectors.
solar energy is one of the easiest renewable energy sources to produceespecially photovoltaic solar.
Wind power

Wind energy is obtained from the wind kinetic energy produced by the effect of air currents. Like solar energy, wind energy is a inexhaustible renewable energy but intermittent because it depends on the strength of the wind.
Wind turbines can be installed on land either in high sea. Onshore wind turbines are technically easier to install, but offshore wind turbines are more efficient in terms of energy production.
wind power is one of the most widely used renewable energies in the world.
Hydroelectric power
Hydroelectric or hydraulic energy is obtained from the exploitation of water through marine currents, mills or dams. The water movement drives the turbines that generate electricity. The higher the water pressure, the more energy is produced. Therefore, it depends on rainfall and the flow of rivers.
Geothermal energy
Geothermal energy is that which harnesses the high reservoir temperatures below the earth’s surface for the generation of energy through heat.
bioenergy
Biomass energy consists of combustion of organic waste of animal or vegetable origin. It is used to create biogas which, as fuel, generates a combustible gas that is used to produce electricity.
This energy is one of the most economical and ecological ways to generate electrical energy in a thermal power plant.
Renewable energies in Spain in 2022
The energy transition is characterized by:
- The importance of the use of renewable energies;
- The decarbonization of the energy mix;
- The use of less polluting fuels;
- The self-consumption;
- Include in our lives electric or hybrid vehicle…
Green energy consumption in Spain, although they remain constantly on the risethey are still a small part of the total.
Gross final consumption of energy from renewable sources in Spain stood at 17.41% in 2018below the European Union average of 18% and far from the 20% target set for 2020.
What are the most used renewable energies in Spain?According to the Ministry for the ecological transition and the demographic challenge, the highest growth compared to 2017 in the primary consumption of renewable energies in 2018 has been registered in hydraulic energy, 87.4%, because 2018 was a year with high hydraulic availability. There was also an increase of 30.7% in biofuelsfrom 3.6% in wind power and 1.3% in biogases.
For its part, the Photovoltaic Solar Energy (-7.5%) and the Thermal solar energy (-14.6%) registered decreases compared to 2017 due to the fact that 2018 was a year with low solar radiation, reaching the lowest primary consumption since 2013.
Contract renewable energy
After the liberalization of the electricity companies market In 2014, the consumer became the true protagonist and since then he can choose between different energy contracting modalities or choose the energy marketer that suits him best.
Besides, the concern for the environment is increasing among consumers. For this reason, it is increasingly common to see how marketers offer their customers rates based on this type of energy. Big energy companies like Iberdrola, Endesa, risky either EDP They already offer these rates, but there are also other types of companies that sell renewable energy, such as EDP, Gesternova either pruning.
What is green energy?Green energy is the way to name the energy generated from the use of sustainable mechanisms. To obtain this type of energy, the natural resourcesso it does not harm the environment and is more sustainable.