Renewable Energy Examples
You've probably heard of wind power, biomass energy, and hydropower, but how do you know which of these renewable energy sources can benefit you the most? Here are some examples. And if you want to know more, check out these related articles.
We'll talk about each in detail so that you can see how each one can benefit you. And remember, these are just a few of the many examples of renewable energy.
What is Solar Energy?
Solar energy, a remarkably abundant and extensively accessible form of renewable energy on our planet, holds the key to a cleaner and sustainable future. At its core, solar energy effectively taps into the infinite power of sunlight, converting its radiant rays into usable electricity through the ingenious utilization of photovoltaic (PV) cells or concentrated solar power (CSP) systems.
The sheer magnitude of solar energy's potential is awe-inspiring. Earth receives an astonishing amount of sunlight each day, and this bountiful supply has the capability to meet our energy needs manifold times over. Harnessing solar energy not only lessens our reliance on finite fossil fuels but also substantially mitigates the environmental impact associated with conventional energy sources, such as greenhouse gas emissions and air pollution.
The core technology behind solar energy, photovoltaic cells, is a marvel of modern engineering. These cells contain semiconductor materials, such as silicon, which undergo a fascinating process of electron excitation when exposed to sunlight. As the photons from the sun strike the surface of the solar cells, they knock loose electrons, generating an electric current that can be captured and transformed into electricity for powering homes, businesses, and industries.
How Does Solar Energy Work?
Solar energy works through the ingenious utilization of photovoltaic (PV) cells or concentrated solar power (CSP) systems to harness the radiant energy emitted by the sun and convert it into usable electricity.
Photovoltaic (PV) Cells
PV cells, also known as solar cells, are the primary technology behind solar energy. These cells are made from semiconductor materials, typically silicon, which have unique properties that enable them to generate electricity when exposed to sunlight. The process can be broken down into the following steps:
- Absorption of Sunlight: When sunlight strikes the surface of the PV cell, it is absorbed by the semiconductor material. The energy from the photons in the sunlight is transferred to the electrons within the material, exciting them to a higher energy state.
- Electron Movement: The excited electrons become mobile and create an electric current within the solar cell. The material's structure guides these electrons along a specific path, creating a flow of electricity.
- Electrical Generation: The electric current generated by the movement of the excited electrons is captured by metal contacts on the surface of the PV cell. These contacts facilitate the transfer of the electricity to an external circuit, where it can be utilized to power electrical devices or be stored in batteries for later use.
- Direct Current to Alternating Current: Most electrical appliances and devices in our homes and businesses require alternating current (AC) electricity. To convert the direct current (DC) electricity produced by PV cells into AC electricity, an inverter is used.
- Grid Connection or Standalone Systems: Solar energy systems can be connected to the electrical grid, allowing excess electricity to be fed back into the grid and earning credits or revenue. Alternatively, they can function independently as standalone systems, supplying power to remote locations or areas without access to a centralized grid.
Concentrated Solar Power (CSP) Systems
Concentrated solar power (CSP) systems use mirrors or lenses to concentrate sunlight onto a small area, typically a receiver. The intense heat generated at the receiver is used to produce steam, which drives a turbine connected to a generator, ultimately producing electricity. The process in CSP systems involves the following steps:
- Solar Concentration: Reflective surfaces, such as mirrors or lenses, are used to concentrate sunlight onto a focal point. This focused sunlight creates extremely high temperatures at the receiver.
- Heat Transfer: The concentrated sunlight heats a fluid medium, such as water or oil, within the receiver. The fluid absorbs the solar heat and reaches high temperatures.
- Steam Generation: The hot fluid is then used to produce steam, which powers a steam turbine.
- Electricity Generation: The steam turbine is connected to an electricity generator, which converts the mechanical energy from the turbine into electrical energy.
- Energy Storage (Optional): Some CSP systems incorporate energy storage technologies, such as molten salt, to store excess heat and continue generating electricity during periods without direct sunlight.
What is Hydropower?
If you're looking for an example of renewable energy, consider hydropower. It's clean energy, and a significant portion of the electricity in Washington will come from this source by 2020.
However, hydropower does have some environmental impacts. Here are some facts about hydropower. These facts may surprise you. Hydropower is one of the most cost-effective sources of energy.
If used properly, hydropower can provide a large amount of electricity without causing any significant environmental harm.
It's difficult to ignore the fact that hydro reservoirs produce greenhouse gases (GHGs). These gases are released by decomposing organic matter.
Hydropower plants emit CO2 and CH4 as a byproduct of this process. Earlier studies estimated that hydro plants in Brazil emitted up to three times more GHG than coal-fired plants. Extrapolating these data led to estimates that hydro accounted for approximately 4% of global GHG emissions.
How Does Hydropower Work?
Hydropower, also known as hydroelectric power, is a renewable energy technology that harnesses the energy from flowing or falling water to generate electricity. It is one of the oldest and most widely used sources of renewable energy in the world. Here's how hydropower works:
- Water Source: Hydropower systems require a reliable and consistent source of water, typically a river, stream, or reservoir with a significant elevation difference between the upper and lower points. The greater the difference in water elevation, also known as the “head,” the more potential energy can be harnessed.
- Dam or Diversion Structure (Optional): In some cases, a dam is built across a river to create a reservoir, creating an artificial water source with controlled water flow. The dam serves to regulate the water flow and store water for times of high demand or low natural flow. Alternatively, in run-of-the-river systems, there might not be a large dam, and the water is diverted from the river directly to the turbines.
- Penstock: The water is then directed through a large pipe or channel called a penstock. The penstock carries the water from the dam or diversion structure to the turbine located at a lower elevation.
- Turbines: At the end of the penstock, the water is directed onto the blades of a turbine. The force of the moving water causes the turbine blades to rotate. There are different types of turbines used in hydropower systems, such as Francis, Pelton, or Kaplan turbines, depending on the specific characteristics of the water flow and head.
- Generator: As the turbine rotates, it drives the shaft of an electric generator. The generator consists of coils of wire within a magnetic field. The rotational movement of the turbine shaft induces a flow of electrons in the wire coils, creating an electric current.
- Electricity Generation: The electric current produced by the generator is in the form of alternating current (AC). Before being fed into the electrical grid, the AC current is typically converted to a higher voltage through transformers for efficient transmission over long distances. The electricity is then distributed to homes, businesses, and industries for various uses.
Where Can You Get Hydropower?
Hydropower can be harnessed in various geographical locations where there is a reliable and consistent source of flowing or falling water. Here are some common places where hydropower can be obtained:
- Rivers and Streams: Rivers and streams with significant flow and elevation differences provide excellent opportunities for hydropower generation. Dams or diversion structures can be built across these water bodies to regulate the water flow and create a reservoir, which allows for the controlled release of water to drive turbines.
- Waterfalls: Waterfalls are natural locations where water flows from a higher to a lower elevation, creating substantial potential energy. By harnessing the kinetic energy of falling water through turbines, hydropower can be generated efficiently.
- Reservoirs: Existing reservoirs or man-made lakes, which are often created for purposes such as water supply, flood control, or irrigation, can be retrofitted with hydropower infrastructure. Water from the reservoir is released through turbines to generate electricity.
- Run-of-the-River Systems: In regions with consistently flowing rivers, run-of-the-river hydropower systems can be employed. These systems do not require large dams and reservoirs but instead divert a portion of the flowing water through turbines to generate electricity.
- Tidal Energy: Coastal areas with strong tidal currents can be utilized for tidal energy, a specific type of hydropower. Tidal turbines are placed underwater to capture the kinetic energy of ocean tides as they ebb and flow.
What is Wind Energy?
The total amount of wind power that can be economically extracted is far greater than the total power demand of all human beings on Earth. Moreover, the average wind speed does not necessarily indicate the amount of energy that a wind turbine could produce.
Moreover, wind power's price is more stable than that of fossil fuels. This makes it a good choice for both residential and commercial purposes. Therefore, wind power has the potential to meet the energy needs of most people.
The main feature of wind turbines is that they do not emit any greenhouse gases. Wind turbines use a three-bladed rotor to convert kinetic energy into electrical energy.
To operate at a high capacity, a wind farm needs to be located in windy regions. A wind farm requires a large area of land and the wind is usually strong. This land is also used for farming, grazing, and other uses.
How Does Wind Energy Work?
Wind energy harnesses the power of the wind to generate electricity. It is a renewable and sustainable energy source that has gained significant popularity in recent years. Here's how wind energy works:
- Wind Turbines: The key component of a wind energy system is the wind turbine. Wind turbines are tall structures with large blades that capture the kinetic energy of the wind. The design of wind turbines has evolved over time, and there are various types of turbines, including horizontal-axis and vertical-axis turbines.
- Wind Flow: When the wind blows, it causes the turbine blades to rotate. The amount of energy that can be extracted from the wind is determined by the speed and density of the wind. Higher wind speeds and greater air density result in more energy being available for conversion into electricity.
- Rotor and Blades: The rotor is the central part of the wind turbine that houses the blades. The blades are aerodynamically designed to efficiently capture the energy in the wind. As the wind blows across the curved surfaces of the blades, it exerts a force on them, causing them to rotate.
- Shaft and Gearbox: As the blades rotate, they turn a shaft connected to a gearbox. The gearbox increases the rotational speed, making it suitable for driving the generator that produces electricity.
- Generator: The rotating shaft is connected to an electric generator. The generator consists of a rotor and stator. As the shaft rotates the rotor inside the generator, it creates a magnetic field, which induces a flow of electrons in the wire coils of the stator. This electromagnetic induction process generates electricity.
- Control System: Modern wind turbines are equipped with sophisticated control systems that optimize their performance and protect them from extreme wind conditions. The control system adjusts the angle of the blades to maximize energy capture and adjusts the yaw mechanism to ensure the turbine faces into the wind.
Where Can You Get Wind Energy?
Wind energy can be harnessed in various locations where there is a consistent and adequate supply of wind. The best locations for wind energy are typically characterized by high wind speeds, open spaces, and accessibility for the installation and maintenance of wind turbines. Here are some common places where wind energy can be obtained:
- Onshore Wind Farms: Onshore wind farms are one of the most common and economically viable sources of wind energy. They are typically established in open plains, hills, or coastal areas where wind speeds are consistently high. Onshore wind farms are relatively easier to develop and maintain compared to offshore installations, making them popular choices for wind energy projects worldwide.
- Offshore Wind Farms: Offshore wind farms are located in bodies of water, such as seas or large lakes. They take advantage of strong and consistent winds over water surfaces. While offshore wind farms can be more complex to construct and maintain due to challenging marine conditions, they have the advantage of higher wind speeds and reduced visual impact on landscapes.
- Coastal Areas: Coastal regions often experience strong and consistent winds, making them suitable for wind energy projects, both onshore and offshore.
- Mountain Passes: Wind tends to be accelerated through mountain passes and valleys, creating favorable conditions for wind energy generation. Mountainous regions with consistent winds are often considered for wind energy installations.
- Islands: Islands, especially those exposed to prevailing winds, are potential sites for wind energy projects. Off-grid islands can benefit significantly from wind energy, providing a reliable and renewable source of electricity.
What is Biomass Energy?
As a form of renewable energy, biomass is a viable alternative to fossil fuels. Most forests will not be clear-cut for biomass production. The regrowth of plants offsets the carbon emitted by burning these fuels.
However, environmental activists worry that the increasing demand for biomass will increase global pressures on the environment and social systems.
This is due to biomass' low surface power density, which means that a larger land area is needed to produce the same amount of energy as biomass.
However, a biomass power plant may require a large investment. The initial cost of installing and operating biomass power plants is often higher than fossil fuels. The benefits of using biomass power are numerous.
It reduces emissions and supports local economies by creating a new market for biomass products and reducing reliance on fossil fuels. It also reduces greenhouse gas emissions and has multiple environmental benefits.
How Does Biomass Energy Work?
Biomass energy harnesses the energy stored in organic materials derived from plants, animals, and waste products. It is a renewable energy source that can be converted into heat, electricity, or biofuels. Here's how biomass energy works:
- Electricity Generation: Biomass energy can be used to generate electricity through various means. Biomass power plants typically consist of a boiler or gasifier, which converts the biomass into steam or syngas. The steam or syngas then drives a turbine connected to a generator, producing electricity.
- Cogeneration: Cogeneration, also known as combined heat and power (CHP), is a process where both heat and electricity are generated from biomass energy. The waste heat produced during electricity generation is used for district heating, industrial processes, or space heating, increasing overall energy efficiency.
- Environmental Considerations: Biomass energy is considered renewable because new plant growth can absorb the carbon dioxide emitted during the combustion or conversion process. However, the sustainability of biomass energy depends on responsible sourcing practices and ensuring that the rate of biomass harvesting does not exceed the rate of biomass regeneration.
Where Can You Get Biomass Energy?
Biomass energy can be obtained from various sources where organic matter is available. Biomass refers to any biological material derived from recently living organisms or their byproducts. Here are some common sources from which biomass energy can be obtained:
- Agricultural Residues: Biomass energy can be derived from agricultural residues such as crop residues (e.g., corn stalks, rice straw), sugarcane bagasse, and other plant materials left over after harvesting.
- Forest Residues: Biomass energy can be obtained from forest residues, including tree branches, tops, and other woody biomass that remains after logging or forest management activities.
- Energy Crops: Dedicated energy crops, such as switchgrass, willow, and miscanthus, are grown specifically for biomass energy production. These crops are fast-growing and have a high energy content.
- Organic Waste: Biomass energy can be derived from organic waste materials, including food waste, yard waste, and municipal solid waste. These materials can be converted into biogas through anaerobic digestion or other processes.
- Animal Manure: Livestock manure can be used as a source of biomass energy through anaerobic digestion, which produces biogas for electricity generation or as a fuel for heating and cooking.
- Wood and Wood Waste: Biomass energy has been traditionally obtained from wood and wood waste, including sawdust, wood chips, and wood pellets, which can be used for heating, electricity generation, or as a transportation fuel.
What is Wave Energy?
Although wave energy is not a renewable energy source by itself, it can play a role in the energy mix. In fact, its peak is seasonal and thus it is complementary to solar.
Some companies are working on wave power and plan to test their devices at U.S. Navy Energy Test Site in Hawaii. Regardless, a better understanding of the technology and its benefits will be essential to determining its place in the energy mix.
The greatest potential for wave energy is in areas of high winds, such as the Atlantic Ocean, Pacific Ocean, and British Seas. There are many technologies for harvesting this natural energy source. Some of them resemble giant undersea metallic balloons, while others are made of an enclosed chamber.
The tubes contain individual power generators that activate as waves pass. The process of harvesting wave energy is a complex one, and no one technology exists yet.
The technology behind wave power is not new. In fact, Girard and his sons had patented their concept as early as 1799. In the 1940s, the Empire of Japan took up the challenge and developed wave energy technology.
How Does Wave Energy Work?
Wave energy, also known as wave power or ocean wave energy, is a renewable energy technology that harnesses the energy from ocean waves to generate electricity. It involves capturing the kinetic energy of waves and converting it into usable electrical power. Here's how wave energy works:
- Wave Energy Devices: Wave energy devices, also called wave energy converters (WECs), are deployed in coastal areas or offshore locations where there is a significant wave energy resource. These devices are designed to interact with ocean waves and convert their motion into mechanical or hydraulic energy.
- Energy Conversion and Grid Connection: The mechanical or hydraulic energy generated by the wave energy devices is converted into electrical energy through hydraulic pumps, air turbines, or electrical generators. The electricity produced is typically in the form of alternating current (AC). Before being integrated into the electrical grid, the AC current is converted to higher voltage levels through transformers for efficient transmission over long distances. Wave energy farms, consisting of multiple WECs, are often connected to the grid to supply electricity to consumers.
- Environmental Considerations: Wave energy is considered a green and sustainable energy source as it produces no direct greenhouse gas emissions or air pollutants during operation. However, like any renewable energy technology, wave energy projects must consider potential environmental impacts, such as marine life disturbance and coastal dynamics.
Where Can You Get Wave Energy?
Wave energy can be harnessed in coastal areas and offshore locations where there is a consistent and significant wave resource. The availability of wave energy depends on the presence of suitable ocean wave patterns and the proximity to the coast. Here are some common locations where wave energy can be obtained:
- Coastal Areas: Coastal regions with significant wave activity are prime locations for wave energy projects. These areas experience the interaction of ocean currents and wind, generating consistent and powerful waves.
- Offshore Sites: Offshore locations, away from the coast, can also be suitable for wave energy projects. Offshore wave energy devices can take advantage of large swells and waves generated by storms and other weather conditions.
- Areas with Strong Winds: Regions with strong and persistent winds, such as those along the path of prevailing winds or in areas with frequent storms, tend to have higher wave energy potential.
- Open Ocean: In open ocean areas, away from coastal obstructions, wave energy can be harnessed with greater efficiency and consistency.
- Island Coasts: Coastal regions of islands, especially those exposed to ocean swells, can be potential sites for wave energy projects to provide renewable energy to island communities.
- Coastal Cities: Coastal cities and towns with high electricity demands can explore wave energy as a local renewable energy source.
What is Geothermal Energy?
In a district heating system, geothermal energy is used to heat buildings and provide hot water to homes. The hot water is piped from underground to buildings, where it can be used for heating.
The same method is used for industrial settings, where the heat from the water can heat the buildings. Ultimately, geothermal energy is a clean and renewable energy resource, but it is not without risks.
Geothermal reservoirs are located in the western United States and Alaska. The United States produces more electricity from geothermal sources than any other country in the world.
It was only a fraction of the nation's energy supply in 2015 but is projected to grow by 4.9% per year by 2040. Until then, geothermal energy will remain less than one percent of the nation's total energy use.
The heat is produced in the Earth's interior through the radioactive decay of elements and friction on the margins of continental plates. The heat flows to the surface annually in the form of low-grade heat, and it is a source of electricity for humans.
The energy is virtually limitless and is available around the clock. Unlike wind and solar energy, geothermal energy is not dependent on changing weather conditions.
How Does Geothermal Energy Work?
Geothermal energy harnesses the heat from within the Earth to generate electricity or provide direct heating and cooling for buildings. It is a renewable and sustainable energy source that taps into the Earth's natural heat reservoirs. Here's how geothermal energy works:
- Geothermal Heat Sources: The Earth's interior contains vast amounts of heat, primarily generated by the natural decay of radioactive elements in the Earth's crust and mantle. This heat is continuously replenished and stored within the Earth's rocks and fluids, creating geothermal heat sources.
- Geothermal Reservoirs: In certain regions, geothermal heat is closer to the Earth's surface, creating geothermal reservoirs. These reservoirs can be found in volcanic areas, geologically active regions, and tectonic plate boundaries, but they can also be present at shallower depths in some other areas.
- Drilling Wells: To harness geothermal energy, wells are drilled into the Earth to access the hot geothermal reservoirs. The depth of the wells depends on the local geothermal conditions, but it can range from hundreds to thousands of meters.
- Geothermal Fluids: When the wells reach the geothermal reservoirs, hot water or steam, known as geothermal fluids, is brought to the surface. The geothermal fluids contain the high-temperature heat energy extracted from the Earth.
Where Can You Get Geothermal Energy?
Geothermal energy can be obtained in regions with suitable geological conditions that allow access to the Earth's natural heat reservoirs. Geothermal energy is most abundant in areas where the Earth's crust is thin or fractured, facilitating the transfer of heat from the deeper layers to the surface. Here are some common locations where geothermal energy can be harnessed:
- Geothermal Hotspots: Geothermal energy is particularly abundant in areas with geothermal hotspots, which are often associated with tectonic plate boundaries and volcanic activity. Examples of such regions include the Pacific Ring of Fire, the East African Rift, and Iceland.
- Volcanic Regions: Volcanic areas are prime locations for geothermal energy. The presence of active or dormant volcanoes indicates the potential for high-temperature geothermal reservoirs.
- Tectonic Plate Boundaries: Geothermal energy is commonly found near tectonic plate boundaries, where the Earth's crust is subject to geological forces, leading to geothermal activity.
- Hot Springs and Geysers: Areas with natural hot springs and geysers are indicative of geothermal heat close to the surface.
In conclusion, exploring and understanding the various renewable energy sources can be both enlightening and empowering. As an individual, I find myself inspired by the vast potential of solar energy, which harnesses the boundless power of sunlight to create a cleaner and more sustainable future. The thought of our planet receiving an astonishing amount of sunlight each day, capable of meeting our energy needs manifold times over, fills me with hope for a greener world.
Moreover, learning about the efficiency and versatility of wind energy reminds me of the importance of harnessing the forces of nature to our advantage. The prospect of wind turbines, standing tall and gracefully turning the kinetic energy of the wind into usable electricity, symbolizes our ability to tap into natural resources without harming the environment.