We live in an exciting time, which surpasses any Jules Verne novel in the intensity of passions and the flight of scientific thought. Today, the dream of a wonderful and harmless fuel can take a company’s capitalization to the top and generate millions of supporters all over the planet. The question, as in life, is only how much this dream is connected with reality, where is the truth and where is fiction. Let’s connect critical thinking to figure it all out.
Fossil or renewable?
Most of the energy we consume today comes from oil, coal, and natural gas. These hydrocarbons provide electricity, heat, and cooling for our homes and workplaces. They also power the transportation systems that take us to work or school, and even the ones we use to go on vacation. They also enable industry to support our lifestyles , as well as produce the chemical ingredients that go into many of the products we buy, such as the device you are using to read this page.
Fossil fuels produce energy by burning, causing harmful emissions in the form of greenhouse gases such as carbon dioxide. And the curse here is that the more people there are on the planet, the more fuel is consumed.
In 2018, global fossil fuel emissions were 60% higher than in 1990 [ La Vanguardia, 2019 ].
Global demand for energy is growing, driven by population growth and expected rising living standards . The world population is expected to reach 9 billion by 2050. Many people from emerging economies will join the global middle class. They will buy refrigerators, computers, and other energy-intensive devices. And many of them will buy cars, the number of which on the streets is expected to at least double, although it is expected to increase even more.
The prosperity and development of individuals and households, as well as economies and communities, depend on the timely, safe and sustainable availability of energy. Today, people are more connected than ever before. More and more of us enjoy better opportunities, better health and a higher standard of living.
To maintain this pace, the world will need even more energy than before. The question is where to get it.
Main options:
- Go back to the past, to wood and coal.But the truth is that wood is becoming less and less valuable, including in terms of protecting the planet’s biodiversity and animal habitats. And it is technically impossible to “feed” the same coal to your gadget.
- Living as beforeis also not an option, because land-based sources of fossil fuels are shrinking, there are very few new deposits, and extracting at sea is an order of magnitude more expensive. In the long term, this option threatens the depletion of resources.
- Switch to solar, water and wind energy.Humanity is already doing this, but so far the problem rests on the efficiency factor (EFF), high start-up costs and unforeseen circumstances.
- Invent other energy sources.For example, hydrogen used to lift giant airships into the air. And they exploded. That’s why ideas alone are not enough, we need specific developments and safety justifications.
Humanity began thinking about energy globally after World War II, when the United Nations was founded and the space age began. It was hypothesized that to combat climate change, energy should preferably come from lower-carbon sources. In simple terms, a global alternative to fossil fuels is needed. This is what we call “renewable energy.”
The UN describes renewable energy as a type of energy derived from natural sources that can be replaced faster than they can be consumed. Examples of such sources are, for example, sunlight, water and wind. Their sources are constantly renewed.
Renewable energy sources are many and we find them in every environment, while fossil fuels such as coal, oil and gas are non-renewable energy sources that take hundreds of millions of years to form.
Renewable energy is energy that can be replenished naturally indefinitely. Under normal conditions and with rational and systematic use, this resource will not be used up. That is, renewable energy sources are those that are based on sources that can be regenerated.
This is the main difference with most of the energies we use, such as fossil fuels, which are limited because at some point the resources will be exhausted.
Thus, the more we delay the transition from fossil energy to renewable and clean energy, the more costs we will have at the economic, environmental and social level, since renewable energy is the most economic, environmental and socially responsible, equitable and just option for preserving our planet, the UN emphasizes.
Producing more and more renewable energy is a need that all countries in the world recognize. According to the latest report from the International Renewable Energy Agency (IRENA), in 2022, up to 83% of all added electricity capacity came from renewable sources. While in 2021, according to a report published by Ember, an independent climate think tank, renewable energy generated 38% of the world’s electricity [ Enel, 2024 ].
Renewable energy sources received important support from the international community thanks to the Paris Agreement, signed at the World Climate Summit held in December 2015 in the French capital.
The agreement, which entered into force in 2016, sets the first binding global target, with nearly 200 signatory countries committing to cut their emissions to curb the rise in the planet’s average temperature.
In addition to ecology, there is another very important aspect – politics. Not all countries have fossil fuels, but everyone needs energy. Conclusion: we have to extract it ourselves, so that in case of wars, crises or pandemics we do not end up in a frozen house.
Renewable energy does not rely on the extraction and transportation of fossil fuels, reducing dependence on international markets and the risk of price fluctuations. States rely on these clean sources to guarantee their energy sovereignty.
Since renewable energy does not depend on the transportation of hazardous fuels, it is also safer. The originators of this concept were those who personally experienced the horror of the Chernobyl disaster and saw the enormous damage to the sea coastline, flora and fauna caused by a single sunken oil tanker.
However, we must not forget that people have been using fossil fuels for centuries, and renewable energy is still largely a start-up and venture, where risks and uncertainty are high. Therefore, the slogans circulated by the media that “renewable energy sources are destined to become the most profitable source of electricity for the planet and economic development” must be treated with caution.
After all, the final commercial profit consists of:
- demand;
- profitability;
There are no problems with demand. But profitability is limited by efficiency, and costs are still high. And not only financial, but also environmental, social, moral, noise, etc.
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From here we can move on to another concept that is so deeply rooted in people’s minds that many do not even know that it is a misconception. There is an opinion that all renewable energy sources are clean, i.e. do not pollute the environment. This is not entirely true, since almost all renewable energy sources pollute the environment . Some more, some less.
Consider that “you can’t fry an egg without breaking eggs”: you can’t build a “green” wind turbine without producing waste, a carbon footprint, driving moles out of the area, and other environmental consequences.
A great example is biodiesel, which is renewable because it comes from inexhaustible natural sources, but, unlike most renewable energy sources, pollutes the environment when burned, releasing greenhouse gases [ Telefonica, 2024 ].
Therefore, each type of renewable energy source needs to be considered separately.
Solar or solar energy
For centuries people have known that it could be used, but for a long time they did not know how.
This type of renewable energy consists of using the electromagnetic radiation of the Sun using photovoltaic cells, solar collectors or heliostats.
Solar energy itself can be:
- Photovoltaic modules work with silicon semiconductors that convert sunlight into electricity.
- Solar energy is used to produce heat. In this case, solar thermal collectors use sunlight to heat oil or water.
The largest solar park in the world is in China. The Longyangxia Dam station has more than 4 million panels. They generate about 850 MW of electricity, enough for 140,000 private homes.
Solar energy has enormous potential for development, as the sun can be used as an energy source to a greater or lesser extent anywhere on the planet. One of the key milestones in understanding the development of solar energy dates back to the 1970s, when the oil crisis led to a search for alternatives that would reduce the rise in crude oil prices.
In addition, this type of renewable energy can be an ideal solution for places where energy export is very difficult and expensive. According to the UN, Hawaii is one example that can be successful. The archipelago, due to its geographical location, aims to become self-sufficient with 100% renewable energy by 2045.
In the southern Mediterranean countries, photovoltaic systems already provide around 20% of all energy produced.
Windmills
The wind is responsible for generating kinetic energy, which is created by the movement of the blades of a wind turbine. The generator converts the kinetic energy into electricity, much like a bicycle dynamo.
Wind power plants have become popular in many regions due to:
- low cost of electricity production;
- government subsidies;
- international “green certificates”;
- geographical conditions.
They are placed not only on land, but also at sea, but the cost of building such sites is much higher.
In 2020, German wind turbines covered 23% of Germany’s total electricity demand [ Our World in Data, 2024 ].
However, every coin has two sides. Wind turbines generate electricity when there is wind. No wind – no electricity. The same situation as with the sun. Calm and cloudy weather can last not just for days, but even for weeks, as the experience of recent years has shown.
Another problem: the impact of wind turbines on flora and fauna. According to the latest data, German wind turbines alone kill millions of bats every year [ Naked Science, 2022 ].
Hydropower
This type of renewable energy uses the movement of water to generate electricity by harnessing the kinetic and potential energy of waterfalls, currents, or tides. The force that causes the movement of water turns a turbine connected to a transformer, which converts the movement into electrical energy.
Hydraulic energy is considered inexhaustible. However, the construction of dams or water retention systems, if not planned properly, has an impact on the environment, changing the ecosystem.
Moreover, the productivity of hydroelectric power plants is directly affected by water content – the water content of rivers and other bodies of water on the banks of which the hydroelectric power plant is located. When a river becomes shallow, electricity production decreases accordingly. Long droughts, which are becoming more frequent on the planet, require the development of new technical solutions and adaptation to climate change.
This category of renewable energy sources also includes tides. It is important not to confuse it with wave energy, which uses the power of waves.
To harness the tides, generators are installed that use the movement of sea water similar to wind turbines.
Geothermal energy
The Earth radiates heat. For every 100 meters deep, the Earth’s temperature rises by three degrees Celsius, and in the Swabian Alps by as much as ten degrees Celsius due to the proximity to volcanic hot spots. This heat can be used to generate electricity.
Geothermal power plants have huge boreholes that penetrate hundreds of meters into the ground. Pumps then transport the water into the warm depths of the earth. At this depth, the relatively cold water turns into steam, which drives turbines and thus electricity generators.
According to the FAO, this type of energy could be very useful in developing countries, as it could be used in drying food or pasteurizing and sterilizing milk.
Biomass and biogas
This is the waste of plants and animals. When this biomass is burned in an anaerobic digester, the process produces heat, which then causes water to boil. The resulting water vapor drives turbines, which produce electricity using generators, much like a classic coal-fired power plant.
Biomass power plants achieve optimum efficiency when they simultaneously use waste heat for heating.
After processing waste, biogas is obtained. The Institute for Diversification and Energy Saving (IDAE) defines it as follows: “It is a gas consisting mainly of methane (CH4) and carbon dioxide (CO2), in variable proportions depending on the composition of the organic matter from which it was formed.”
Bioethanol and biodiesel
Bioethanol is a renewable fuel produced from waste or organic crops. As a plant-based biomass, it is considered a renewable energy source and its use significantly reduces emissions of polluting gases into the atmosphere. In addition, it is the only alternative fuel that is assessed by certifying the entire emissions chain from production to consumption, not just vehicle emissions.
There is also biodiesel, which is poured into engines and used to generate heat and electricity [ BBVA, 2024 ].
In fact, biodiesel is a mixture of triglycerides and fatty acids, which does not contain sulfur. When burned, it produces fewer emissions than traditional hydrocarbons, but the power output is also lower. But most importantly, in the event of an accident, biodiesel is broken down by microorganisms in less than a month.
Biodiesel could be an ideal replacement for classic fossil fuels, if it weren’t for where it comes from. For example, in Colombia, most biodiesel is made from the infamous palm oil. To produce it, traditional rainforest is cut down, which only increases greenhouse gas emissions, habitat destruction, and land degradation.
And here’s another oddity: humanity has been discussing for decades how wonderful it is to pour oil from your morning French fries into your car, avoiding crazy spending at gas stations. But how many people do you know who do this? If so, in which countries do they live, and are there statistics on such consumption in these countries?
So far, the bulk of articles on this topic are written by scientists who discuss chemical processes. And real journalists report on the formation, for example, in the EU of a “black market” for used oil. In other words, fast food waste is simply stolen and then resold with forged documents to large corporations that previously specialized in the production of fossil fuels. For example, the Spanish Repsol [ JF Samaniego, 2024 ].
It turns out that both Spanish and Colombian practices are based on the assumption that the average consumer, enchanted by the magic words about protecting the environment, will not conduct a chemical analysis of the fuel used in the household and find out what kind of potatoes were floating in it. The car is driving, and that’s fine.
The problem here is more about long-term forecasting and understanding how all these factors affect both us and the environment. We can definitely help with the former, and for this purpose we launched the online program “Human Health: Biohacking by Science” .
How is renewable energy stored?
Renewables have another problem: storage. The sun shines irregularly. The wind is fickle. The solution: store electricity from renewables in batteries and supercapacitors.
Energy-to-gas conversion is also possible: an electrolysis system uses excess electricity to split water into its chemical components, oxygen and hydrogen. Hydrogen can be stored as an energy source. During recovery, fuel cells convert the chemical energy of hydrogen into electricity.
Excess electricity from renewable sources can be used to operate pumps that move water to a reservoir located at an elevated location. The water is returned to its starting point through electric turbines to restore energy.
Another storage option: Using excess electricity, compressors pump air to compressed air storage facilities underground, in salt caverns or in rock layers beneath the seabed. To regenerate, the compressed air is passed through turbines that drive electric generators.
You can learn more about how to learn to live with benefit for the world around you in our express course “Rational Consumption” .
Projects of the future
At the beginning of the 21st century, the renewable energy market is one continuous frontier, where multi-billion dollar empires are created and destroyed in the blink of an eye, traditional pipelines are blown up, and ordinary people prefer not to ask energy companies questions and not to leave their homes, lest, God forbid, they get shot. If you don’t want to be like that, welcome to our program “Critical Thinking” .
Therefore, let us leave commercial issues to energy companies and politicians, and let us concentrate on the flight of human thought .
This is what humanity is thinking about today:
- Photovoltaic ink. One of the key problems that solar energy still poses is the high cost of producing solar panels. The US National Renewable Energy Laboratory is working on new ways to use photovoltaic energy, such as photovoltaic ink. This material makes it much easier to coat potentially energetic surfaces.
- Floating solar panels.Another solution proposed to make the best use of photovoltaic energy involves using the available space to place solar panels. One option being studied is the possibility of placing floating solar panels on surfaces covered by water. This way, not only the sea surface but also the flooded areas can be used.
- Windmills:Indian engineers are creating twin-rotor models that can generate up to 20% more energy than current models.
- Volcanic Energy.Another energy achievement that we will see in the coming years is in Iceland. Geothermal energy itself is nothing new, but we are talking about its use in such unfavorable places for the construction of power plants, like the crater of a volcano. With the development of technology, it is planned that in the future, volcanoes will be able to supply energy continuously and safely. Considering that, according to the postulate, energy is neither created nor destroyed, but only transformed, don’t you think that volcanoes are an impressive energy treasure?
- Inspired by photosynthesis. Using the same mechanism that plants use, we will be able to obtain electrical energy from designer plant organisms connected to batteries, which in turn will be powered by the public grid. One of the pioneers in this field is the Belgian company Plant-e.
- This type of energy uses the movements we make when walking, dancing, or riding a bike or car. For example, at Stockholm Central Station in Sweden, the steps of travelers on a special sidewalk generate energy to heat the building. Nightclubs in Japan and Holland light up thanks to the dancing of their customers. All this is made possible by installing floors specially designed to convert the kinetic energy of footsteps into electricity.
- The energy potential of rain.Chinese scientists have developed an electric generator called Electrec that converts rain energy into electricity. Early tests have shown that the impact of a single raindrop can generate enough energy to light 100 light bulbs. Can you imagine how much energy you can get from a good rainstorm?
- Bioluminescence. This is a phenomenon that can be observed in jellyfish, fireflies, some bacteria and more than 80% of marine organisms. They produce fluorescent light naturally, through a chemical reaction of certain proteins. The possibilities for using this process in indoor lighting are extraordinary and have already been successfully tested in some new initiatives. For example, in Paris, they have organized the lighting of some streets using bioluminescence. The French company Glowee is a pioneer in the development and application of this type of renewable energy. For many years, it has been researching the luminescent bacteria Aliivibrio fischeri. Bioluminescence can be used to illuminate streets, pedestrian crossings, bus stops, road signs, posters, shop windows, fountains and many other elements.
- Flying wind turbines.Imagine drones or balloons hovering at an altitude of about 2 km. Experts estimate that winds in this altitude range are up to 20 times more powerful than those captured by conventional wind turbines. The flying objects are planned to deliver electricity via nanotubes or wirelessly. The potential of this technology is very high, provided that such drones do not interfere with the movement of aircraft.
- This is a natural phenomenon between two liquids with different salt concentrations that exchange molecules through a membrane. Osmosis will cause fresh water to pass through the membrane next to the salt water, increasing the volume and pressure. This drives a turbine, which then generates electricity. The potential for this type of clean energy is very high in the mouths of large rivers, where fresh water naturally mixes with salty sea water. Examples of this type of power plant already exist in Norway and France.
- Energy from Moist Air.This technology, developed by researchers at the University of Massachusetts, uses bacteria called Geobacter sulfurreducens to generate energy from ambient humidity. The bacteria absorb water vapor from the air, even in very dry rooms, and is able to produce an electric current between two electrodes via protein nanowires. Ideally, this would allow devices to be charged or electricity to be generated without the need for cables or a grid.
- Wasteenergy . Waste is burned in incinerators at very high temperatures to produce electricity and biogas. The heat from combustion is converted into steam, which drives turbines that generate electricity. Countries such as Sweden or Norway convert thousands of tons of waste into electricity every year [ Escandinava de Electricidad, 2022 ].
Renewable energy sources are a great area to apply your strength, intelligence, ambition, talents and skills. Who knows, maybe you will give the planet another promising source?