For many, many years, since the 1800s, we’ve relied on fossil fuels. They’ve powered everything around us – our homes, schools, and the places we work. Fossil fuels have been a steady and fairly cheap way to get energy. But there’s a big downside: they release harmful stuff into our air. That’s why so many people are excited about renewable energy. The hope is that one day, these cleaner sources will completely take over from fossil fuels. This could help us slow down, and maybe even undo, some of the damage to our planet.
The good news is that clean energy is getting cheaper. It’s possible that in the next 10 or 20 years, we could see fossil fuels phased out from making electricity. That might sound very hopeful, but it’s what most of us want: energy that’s reliable and doesn’t cost too much, while also taking care of our world.
Let’s explore 10 energy resources that have the potential to become our main power sources in the near future, leaving fossil fuels behind.
Solar Energy
Solar energy is perhaps the most well-known renewable source, tapping into the incredible power of the sun. It’s super green and there’s plenty of it, especially in places like the United States which gets a lot of sunshine. We can use solar tech for lots of things: lighting up our rooms, keeping our homes warm, and heating water for our houses, businesses, or factories.
There are clever ways to turn sunlight into energy we can use. Think about designs that naturally heat and cool buildings, solar panels (photovoltaics) that make electricity, and systems that heat water using the sun. These are popular for both homes and businesses. Using solar power helps companies use different types of energy, work more efficiently, and even cut down on costs.
Compared to fossil fuels, solar energy is much better for our planet because it produces far fewer harmful emissions and can last forever. But, it’s not perfect. You can’t make solar power at night, and in places with little sunlight, solar panels aren’t very effective. Getting a solar power system set up can also be quite pricey at first, and you need a good amount of space if you need a lot of panels.
Wind Energy
Wind energy, or wind power, comes from using wind turbines. These big structures capture the wind’s motion to make electricity. Anything that moves has energy (called kinetic energy), and clever scientists and engineers use the wind’s movement to create clean power.
Wind turbines are incredibly powerful. Even small ones can make enough electricity (about 100 kilowatts) to power a home. Bigger turbines, with blades stretching 130 feet, can produce 1.8 megawatts of electricity. And the really huge ones? They can generate anywhere from 4.8 to 9.5 megawatts! That’s a lot of power.
Experts say that wind energy, when combined with solar power, has way more potential than fossil fuels. Together, they could easily meet all the world’s energy needs. Right now, with the technology we have, we can get over 6,700 petawatt-hours from sun and wind globally. That’s more than 100 times the energy the whole world uses!
Geothermal Energy
Geothermal energy is power that comes from the Earth’s own heat. Deep inside our planet, there’s hot magma, and geothermal systems use this heat. This energy is gathered by using steam from hot water pockets found underground. This steam spins a turbine, the turbine makes a generator go, and that’s how electricity is made. It’s a reliable way to get power because the Earth’s heat is always there.
There are three main kinds of geothermal power plants:
- Dry steam plants: These use steam directly from underground. They were the first type ever built.
- Flash steam plants: These are the most common today. They use super hot water (over 360°F or 182°C) that quickly turns into steam.
- Binary cycle plants: These use hot water that’s not quite as hot (between 225°–360°F or 107°–182°C). This hot water heats another liquid with a lower boiling point, which then turns into steam to power the turbine.
The United States is a world leader in making geothermal electricity, producing over 3.5 gigawatts, mostly in the western states. That’s enough energy to power about 3.5 million homes!
Hydropower
Hydropower is energy that comes from moving water. People have been using water’s power for a very long time – more than 2,000 years ago, the ancient Greeks used water wheels to grind grain. It’s a tried and true method!
To get hydropower, which is also called hydroelectric electricity, we usually build a dam or a structure that changes a river’s flow. This controlled water then turns turbines, and these turbines run generators that make electricity. This electricity is then sent out through the power grid to our homes and businesses.
Hydropower was one of the very first ways people made electricity. For a long time, it was the biggest source of renewable electricity in the United States, right up until 2019. Today, hydropower still makes up a big chunk: about 37% of all renewable electricity and 7% of all electricity produced in the U.S.
Biomass
Biomass is a type of renewable energy that comes from organic materials, meaning things that were once living, like plants and animals. Think of it as energy from nature’s leftovers! People have used biomass for ages – even early humans used wood fires for cooking and warmth. Nowadays, we use biomass to power generators and other machines.
Wood is still the most common thing used for biomass energy. But there are many other sources too. These include:
- Food crops grown specifically for energy
- Grasses and woody plants
- Algae that are rich in oil
- Leftovers from farming or forestry work
- The organic parts of trash from cities and industries
- Even gases from landfills (like methane, which is in natural gas) can be turned into biomass energy!
Believe it or not, biomass was the main source of energy in the United States until the mid-1800s. In many countries, especially developing ones, biomass is still widely used for cooking and heating. To help cut down on pollution from fossil fuels, many developed countries are also using more biomass for transportation fuel and making electricity.
Hydrogen Energy
Hydrogen is all around us! It’s a key part of water, plants, animals, and even people. But while it’s in almost everything that’s alive, it’s rare to find hydrogen all by itself as a gas. The cool thing is, if we can separate hydrogen from other stuff, we can use it as a fuel to make energy. We can produce hydrogen using natural gas, nuclear power, biogas, or even renewable sources like solar and wind power.
Hydrogen is a very clean fuel. When it’s used in something called a fuel cell, the only thing it produces is water! This makes it a great choice for powering cars, homes, and even portable gadgets. It’s also becoming a good way to store energy made from renewables, so we can use that energy later when we need it.
There are a few ways to make hydrogen fuel today. The most common methods are by using natural gas in a heat process (called reformation) or by using electricity to split water (called electrolysis). There are also ways to make it using sunlight or natural biological processes.
Tidal Energy
Tidal energy comes from the ocean’s tides – that natural up and down movement of sea levels. These tides happen because of the pull of gravity from the moon and the sun on the Earth. When ocean water moves through a narrow spot, it speeds up, creating strong currents. These currents have enough energy that we can capture and use.
The best places to collect tidal energy are spots where there’s a big difference between high tide and low tide. It also helps if there are channels or waterways that get narrower, making the tidal currents even stronger. While there are many test projects being built, there aren’t any large-scale tidal energy plants running commercially in the United States just yet. But it’s an area with exciting potential!
Wave Energy
Wave energy is another amazing renewable source from our oceans. It’s different from tidal energy. Tidal energy comes from the rise and fall of the sea level due to gravity. Wave energy, on the other hand, comes from the waves that move across the ocean’s surface, which are usually created by wind.
There are a few main ways to capture wave energy:
- One method uses floats or buoys that bob up and down with the waves. This movement powers pumps that can generate electricity.
- Another type uses a tall, hollow tube. As waves push water up and down inside it (like air in a whistle), it spins a turbine. This is called an oscillating water column.
- A third kind uses a channel that gets narrower, funnelling waves to increase their power. This can be built on the shore or out in the sea.
Wave and tidal energy are often more dependable than some other renewables because the equipment can last a long time and work very efficiently. While solar and wind power can be very unpredictable, and ocean energy can change too, the patterns of waves and tides are generally easier to predict.
Nuclear Energy
Nuclear energy is made when tiny particles called uranium atoms are split apart inside a nuclear reactor. This process is called fission. Think of an atom like a tiny solar system: it has a center (nucleus) with even smaller bits (protons and neutrons), and electrons whizzing around it. The forces holding that nucleus together are incredibly strong and store a huge amount of energy. When fission breaks these bonds, that energy is released, and we can use it to make electricity.
Nuclear power plants use uranium fuel to boil water. This creates steam, which then spins turbines to generate electricity. It’s super efficient! Just one tiny uranium pellet, about the size of your fingertip, has the same energy as three barrels of oil, about 2,200 pounds of coal, or 17,000 cubic feet of natural gas. Each little pellet can produce enough heat to make electricity for five years!
Uranium is quite common on Earth, so there’s enough to fuel nuclear power plants for many years. However, nuclear energy is usually thought of as non-renewable. While the process itself doesn’t produce greenhouse gases like fossil fuels, the uranium fuel it uses isn’t renewable – once it’s used, it’s gone.
Ocean Thermal Energy Conversion (OTEC)
Ocean Thermal Energy Conversion, or OTEC for short, is a clever way to make electricity using the ocean’s temperature differences. The water near the surface of the ocean is much warmer than the water deep down. OTEC systems use this temperature gap to run a special kind of engine, called a heat engine.
You can think of OTEC a bit like the way rain happens. The sun heats up surface water, causing it to evaporate and form clouds (like warm surface seawater in OTEC). Winds blow these clouds (like OTEC pumping this warm water). Then, the water vapor in clouds cools and turns back into liquid rain (like OTEC using cold, deep seawater to condense a working fluid to repeat the cycle). OTEC basically pumps warm surface seawater, uses its heat to turn a fluid into vapor which spins a turbine to make electricity. Then, it uses cold water from the deep ocean to cool the vapor back into a liquid, and the whole process starts again.
With rising electricity prices and concerns about climate change, OTEC is becoming a more attractive option, especially for tropical island communities that often rely on expensive oil for power. There’s a big market for this, both in the U.S. and around the world. As OTEC technology gets better, it could even become a good option for places like the southeastern United States.
The journey away from fossil fuels is a big one, but it’s filled with exciting possibilities. These ten energy sources show us that we have many ways to power our world cleanly and sustainably. From the sun’s constant rays to the mighty power of our oceans and the heat beneath our feet, the future of energy looks brighter and greener. While each option has its own set of challenges, continued research and innovation are paving the way for these alternatives to become more efficient, affordable, and widespread. Choosing these paths means choosing a healthier planet for generations to come.
Which of these future energy sources do you find most promising or interesting? We’d love to hear your thoughts! Leave your comment below and join the conversation.
