How many kinds of renewable energy do you know?
Start the car. Turn on the light in the kitchen. Put on a washing machine or take the escalator. Do you know how much energy each of those little ordinary gestures we make each day of our life requires? And most importantly, do you know where that energy comes from? Energy sources are essential for our society; the whole world moves thanks to them and we need them to live.
What do we call renewable energies?
There are many types of energy, both renewable and non-renewable. The downside is that the non-renewable are based on elements, such as fossil fuels, which end up running out and disappearing. For this reason, renewable energies are presented as a logical and, usually, more sustainable option.
When we talk about renewable energies we commonly refer to those energy sources of natural and potentially inexhaustible origin. This may be because there is an immense amount that humanity will never use up, or because they regenerate by fast natural means and beyond human influence.
Do you know all the types of renewable energy, the difference between them, which are better, which are worse, and why? Let's check your knowledge, come on… it's a very simple test ...
Guess what energy it is …
The first renewable energy we talk about is one of the most common: the use of the force of water in rivers or lakes to generate electricity. This is the one longest used around the world and in some European countries it has been fundamental for the development and improvement of the standard of living. In Spain it is also one of the most widely used renewable energies: about 15% of the energy we consume comes from it, although there are those who raise that figure to 20% worldwide. Yes, you guessed, it's hydroelectric power.
The second of renewable energies comes from the wind. Specifically, the kinetic force of by air currents, captured by turbines that transform it into electrical energy. This is a way of generating energy that is growing significantly around the world: in 2016 it grew by 12.4%, reaching an installed capacity of 486,749 MW. It is currently the second most common source of electricity among renewable energies. Of course, it was very easy to guess: we are talking about wind energy.
There is another form of energy that is based on the use of heat that emerges from the interior of our planet. There are areas of the earth where the temperature is very high and this can be used to boil water and drive turbines and generate electricity or to provide hot water and heating to homes and buildings. In certain countries it is very important due to their special conditions, for example in Iceland it accounts for 13% of the total electricity production. We are talking about geothermal energy.
A fourth way to obtain electrical energy from natural sources is by taking advantage of the movement of the tides, which generate electricity by means of an alternator. This one of the safest and most usable formulae and obviously, it is inexhaustible. This is tidal energy.
The fifth renewable energy on our list is, in a certain way, the most important, since it is the one that gives life and starts up the rest of the renewable energies. This is solar radiation which is collected and turned into other types of energy, such as light or heat through different systems: photovoltaic panels, thermal collectors or mirrors that concentrate it on one point. This energy is well known and we have all heard about it, but for now it only accounts for a very small percentage of the electricity we consume. Yes, of course, we are talking about solar energy.
There is an energy similar to tidal, but instead of drawing on the tides, it uses the movement of the waves. This is one of the most studied systems today due to the ease with which maximum efficiency might be achieved. The name is that of element that produces it: wave energy.
The last type of renewable energy on our list has its origin in plant photosynthesis. During this natural process, the plants transform carbon dioxide and water into organic materials from which a great deal of energy can be obtained through combustion or transformation into other substances that can be used as fuel. It is widely used in Spain, but we rarely see it as an effective renewable energy and its name is not very common either: it is biomass.
Which is the most profitable renewable energy?
You are sure to have passed our simple test and know that renewable energies are still far from becoming the cheapest alternative when choosing an energy option, but they have grown exponentially in recent years. Numerous studies affirm that renewable energies will be the most efficient and cheapest formula for producing electricity by the year 2040 in many countries.
But in the meantime, which is the most profitable today? In Spain, wind energy has experienced the greatest development of all and has therefore become the most widespread renewable energy in the country. Today it can be said that it is the most efficient, cheapest and safest option that exists, and is followed by two other major sources: hydraulic and solar.
However, this is only the case of Spain and the situation varies greatly depending on the country and the usable resources - for example: in Iceland the logical thing is to take advantage of geothermal energy as we have seen they, and also their environmental and energy policies do. A perfect example is the United States, where the use of renewable energy only accounts for 10% of the total, with biomass the favourite. This is followed by hydroelectric, solar, geothermal and wind, so we can see that there are as many preferences as there are options.