Renewable Energies

What are renewable energies? 

Renewable energy is the energy obtained from virtually inexhaustible natural sources, either due to the immense amount of energy they contain or the fact they can regenerate naturally.

What types of renewable energy are there?

Renewable energy sources may be non-polluting (clean) or polluting. The non-polluting kind includes:

• Blue energy: produced where freshwater bodies meet saltwater bodies.
• Wind energy: from wind.
• Geothermal energy: produced with Earth’s heat.
• Hydropower or hydroelectric power: harnesses rivers and freshwater streams.
• Tidal energy: generated by the seas and oceans.
• Solar energy: comes from the sun.
• Wave energy: obtained from waves.

Contaminants are obtained from organic matter or biomass (wood or other solid plant matter). They can be converted into fuel like bioethanol or biogas through organic fermentation processes, or biodiesel through transesterification reactions.

What advantages do renewable energies offer?

• They are non-polluting. They are more environmentally friendly and are the cleanest kind of energy alternative so far.
• They do not generate long-lasting waste. Renewable energy sources are very easy to dismantle and don’t require their waste to be safeguarded for millions of years, as is the case with nuclear energy.
• They promote economic stability. Renewable energies make the area where they are set up more autonomous, which is beneficial both industrially and economically.
• They create jobs. Considering its projected demand and implementation, the employment generated is expected to be even more significant in the coming years.
• They offer safety. Neither related generation nor waste is polluting or poses a health risk.
• They are unlimited, coming from virtually inexhaustible sources like the sun or water. Their various origins also allow them to be used in all kinds of scenarios.
• They’re supported by public opinion. This may seem like a small advantage, but it is not simple or irrelevant to have citizens behind it. In the case of renewable energies, there are more votes for than against, which makes it easier for them to reach everyone little by little.

Are there disadvantages to renewable energies?

These cannot really be considered disadvantages, but renewable energies do have some less favorable aspects. These include:

• The initial investment. Renewable energies offer economic profitability in the medium and long term. However, implementation requires a considerable initial investment, so they are exclusive to some sectors.
• Immediate availability. Due to the increased demand for clean energy and the still low availability of supply, the energy needed is sometimes not available, leading to a wait for sufficient storage.
• The space needed to set up and develop power generation systems. Depending on the source used, systems may need ample space to generate and store enough energy. This is the case, for instance, with solar panels, where a certain number are needed.
• Its diffuse nature. Unfortunately, because they depend on the surrounding landscape, renewable energies are diffuse and must be concentrated in order to be usable. The exception to this rule is geothermal energy, which is already concentrated, but it is only accessible where the Earth’s crust is thin, as with geysers. 

What is the situation around renewable energies in Spain?

In 2021, Spain is ranked eighth in the world in terms of the largest renewable capacity. According to data from International Renewable Energy Agency’s (IRENA) statistical yearbook on renewable power, Spain has 59,108 MW of renewable capacity installed.

Analyzing the data by technology, Spain ranks fifth in wind energy, while it falls outside the top ten for photovoltaic solar energy. The government and private sector agree on developing renewable energies without excluding any technology, and Ferrovial is holding strong in the business of applying renewable energies.

The European Green New Deal, the Clean Energy Revolution program, and the return of the US to the Paris Agreement are just a few examples of the degree of political commitment to reducing greenhouse gas emissions and adopting energy and climate strategies around the world.

Fun facts about renewable energies

• Renewable sources of energy have been used since ancient times. In 200 BC, China and the Middle East used windmills to pump water and grind grain; the ancient Romans were the first to use geothermal energy to heat homes.
• Until recently, renewable energy sources predominated, but the few technologies available impeded their optimal use. Just 150 years ago, wood (a form of biomass), met approximately 90% of our energy needs.
• Albert Einstein is remembered for his work on relativity and gravity, but he received the Nobel Prize for his work in renewable energies for discovering the law of photoelectric effect.
• Every hour, the Earth’s surface receives enough solar energy to meet the world’s needs for an entire year.