Solar Energy 101 – Solar radiation is light – also known as electromagnetic radiation – that is emitted by the sun. While every location on Earth receives some sunlight over a year, the amount of solar radiation that reaches any one spot on the Earth’s surface varies.
Solar technologies capture this radiation and turn it into useful forms of energy. There are two main types of solar energy technologies—photovoltaics (PV) and concentrating solar-thermal power (CSP). You’re likely most familiar with PV, which is utilized in solar panels. When the sun shines onto a solar panel, energy from the sunlight is absorbed by the PV cells in the panel.
This energy creates electrical charges that move in response to an internal electrical field in the cell, causing electricity to flow. Concentrating solar-thermal power (CSP) systems use mirrors to reflect and concentrate sunlight onto receivers that collect solar energy and convert it to heat, which can then be used to produce electricity or stored for later use.
- It is used primarily in very large power plants.
- Solar energy technology doesn’t end with electricity generation by PV or CSP systems.
- These solar energy systems must be integrated into homes, businesses, and existing electrical grids with varying mixtures of traditional and other renewable energy sources.
A number of non-hardware costs, known as soft costs, also impact the cost of solar energy. These costs include permitting, financing, and installing solar, as well as the expenses solar companies incur to acquire new customers, pay suppliers, and cover their bottom line.
- For rooftop solar energy systems, soft costs represent the largest share of total costs.
- Solar energy can help to reduce the cost of electricity, contribute to a resilient electrical grid, create jobs and spur economic growth, generate back-up power for nighttime and outages when paired with storage, and operate at similar efficiency on both small and large scales.
Solar energy systems come in all shapes and sizes. Residential systems are found on rooftops across the United States, and businesses are also opting to install solar panels. Utilities, too, are building large solar power plants to provide energy to all customers connected to the grid.
- 0.1 How do solar panels work without batteries?
- 1 How is solar energy used today?
Why solar energy is the best renewable energy?
Solar energy – a clean source – No greenhouse gas emissions are released into the atmosphere when you use solar panels to create electricity. And because the sun provides more energy than we’ll ever need, electricity from solar power is a very important energy source in the move to clean energy production.
How is solar energy produced?
Solar energy is any type of energy generated by the sun, Solar energy is created by nuclear fusion that takes place in the sun, Fusion occurs when protons of hydrogen atoms violently collide in the sun ‘s core and fuse to create a helium atom. This process, known as a PP (proton-proton) chain reaction, emits an enormous amount of energy.
- In its core, the sun fuses about 620 million metric tons of hydrogen every second.
- The PP chain reaction occurs in other stars that are about the size of our sun, and provides them with continuous energy and heat.
- The temperature for these stars is around 4 million degrees on the Kelvin scale (about 4 million degrees Celsius, 7 million degrees Fahrenheit).
In stars that are about 1.3 times bigger than the sun, the CNO cycle drives the creation of energy. The CNO cycle also converts hydrogen to helium, but relies on carbon, nitrogen, and oxygen (C, N, and O) to do so. Currently, less than 2% of the sun ‘s energy is created by the CNO cycle.
- Nuclear fusion by the PP chain reaction or CNO cycle releases tremendous amounts of energy in the form of waves and particles.
- Solar energy is constantly flowing away from the sun and throughout the solar system,
- Solar energy warms the Earth, causes wind and weather, and sustains plant and animal life.
The energy, heat, and light from the sun flow away in the form of electromagnetic radiation (EMR). The electromagnetic spectrum exists as waves of different frequencies and wavelengths. The frequency of a wave represents how many times the wave repeats itself in a certain unit of time.
- Waves with very short wavelengths repeat themselves several times in a given unit of time, so they are high- frequency,
- In contrast, low- frequency waves have much longer wavelengths.
- The vast majority of electromagnetic waves are invisible to us.
- The most high- frequency waves emitted by the sun are gamma rays, X-rays, and ultraviolet radiation (UV rays).
The most harmful UV rays are almost completely absorbed by Earth’s atmosphere, Less potent UV rays travel through the atmosphere, and can cause sunburn, The sun also emits infrared radiation, whose waves are much lower- frequency, Most heat from the sun arrives as infrared energy.
Sandwiched between infrared and UV is the visible spectrum, which contains all the colors we see on Earth. The color red has the longest wavelengths (closest to infrared), and violet (closest to UV) the shortest. Natural Solar Energy Greenhouse Effect The infrared, visible, and UV waves that reach the Earth take part in a process of warming the planet and making life possible—the so-called ” greenhouse effect,” About 30% of the solar energy that reaches Earth is reflected back into space.
The rest is absorbed into Earth’s atmosphere, The radiation warms the Earth’s surface, and the surface radiates some of the energy back out in the form of infrared waves. As they rise through the atmosphere, they are intercepted by greenhouse gases, such as water vapor and carbon dioxide.
- Greenhouse gases trap the heat that reflects back up into the atmosphere.
- In this way, they act like the glass walls of a greenhouse.
- This greenhouse effect keeps the Earth warm enough to sustain life.
- Photosynthesis Almost all life on Earth relies on solar energy for food, either directly or indirectly.
Producers rely directly on solar energy, They absorb sunlight and convert it into nutrients through a process called photosynthesis, Producers, also called autotrophs, include plants, algae, bacteria, and fungi. Autotrophs are the foundation of the food web,
Consumers rely on producers for nutrients, Herbivores, carnivores, omnivores, and detritivores rely on solar energy indirectly. Herbivores eat plants and other producers. Carnivores and omnivores eat both producers and herbivores. Detritivores decompose plant and animal matter by consuming it. Fossil Fuels Photosynthesis is also responsible for all of the fossil fuels on Earth.
Scientists estimate that about 3 billion years ago, the first autotrophs evolved in aquatic settings. Sunlight allowed plant life to thrive and evolve. After the autotrophs died, they decomposed and shifted deeper into the Earth, sometimes thousands of meters.
- This process continued for millions of years.
- Under intense pressure and high temperatures, these remains became what we know as fossil fuels,
- Microorganisms became petroleum, natural gas, and coal.
- People have developed processes for extracting these fossil fuels and using them for energy.
- However, fossil fuels are a nonrenewable resource,
They take millions of years to form. Harnessing Solar Energy Solar energy is a renewable resource, and many technologies can harvest it directly for use in homes, businesses, schools, and hospitals. Some solar energy technologies include photovoltaic cells and panels, concentrated solar energy, and solar architecture,
There are different ways of capturing solar radiation and converting it into usable energy. The methods use either active solar energy or passive solar energy, Active solar technologies use electrical or mechanical devices to actively convert solar energy into another form of energy, most often heat or electricity.
Passive solar technologies do not use any external devices. Instead, they take advantage of the local climate to heat structures during the winter, and reflect heat during the summer. Photovoltaics Photovoltaics is a form of active solar technology that was discovered in 1839 by 19-year-old French physicist Alexandre-Edmond Becquerel.
- Becquerel discovered that when he placed silver-chloride in an acidic solution and exposed it to sunlight, the platinum electrodes attached to it generated an electric current,
- This process of generating electricity directly from solar radiation is called the photovoltaic effect, or photovoltaics,
Today, photovoltaics is probably the most familiar way to harness solar energy, Photovoltaic arrays usually involve solar panels, a collection of dozens or even hundreds of solar cells. Each solar cell contains a semiconductor, usually made of silicon.
When the semiconductor absorbs sunlight, it knocks electrons loose. An electrical field directs these loose electrons into an electric current, flowing in one direction. Metal contacts at the top and bottom of a solar cell direct that current to an external object. The external object can be as small as a solar-powered calculator or as large as a power station.
Photovoltaics was first widely used on spacecraft. Many satellites, including the International Space Station, feature wide, reflective “wings” of solar panels, The ISS has two solar array wings (SAWs), each using about 33,000 solar cells. These photovoltaic cells supply all electricity to the ISS, allowing astronauts to operate the station, safely live in space for months at a time, and conduct scientific and engineering experiments.
Photovoltaic power stations have been built all over the world. The largest stations are in the United States, India, and China. These power stations emit hundreds of megawatts of electricity, used to supply homes, businesses, schools, and hospitals. Photovoltaic technology can also be installed on a smaller scale.
Solar panels and cells can be fixed to the roofs or exterior walls of buildings, supplying electricity for the structure. They can be placed along roads to light highways. Solar cells are small enough to power even smaller devices, such as calculators, parking meters, trash compactors, and water pumps.
Concentrated Solar Energy Another type of active solar technology is concentrated solar energy or concentrated solar power (CSP). CSP technology uses lenses and mirrors to focus (concentrate) sunlight from a large area into a much smaller area. This intense area of radiation heats a fluid, which in turn generates electricity or fuels another process.
Solar furnaces are an example of concentrated solar power. There are many different types of solar furnaces, including solar power towers, parabolic troughs, and Fresnel reflectors. They use the same general method to capture and convert energy. Solar power towers use heliostats, flat mirrors that turn to follow the sun ‘s arc through the sky.
- The mirrors are arranged around a central “collector tower,” and reflect sunlight into a concentrated ray of light that shines on a focal point on the tower.
- In previous designs of solar power towers, the concentrated sunlight heated a container of water, which produced steam that powered a turbine,
More recently, some solar power towers use liquid sodium, which has a higher heat capacity and retains heat for a longer period of time. This means that the fluid not only reaches temperatures of 773 to 1,273 K (500 to 1,000° C or 932 to 1,832° F), but it can continue to boil water and generate power even when the sun is not shining.
Parabolic troughs and Fresnel reflectors also use CSP, but their mirrors are shaped differently. Parabolic mirrors are curved, with a shape similar to a saddle. Fresnel reflectors use flat, thin strips of mirror to capture sunlight and direct it onto a tube of liquid. Fresnel reflectors have more surface area than parabolic troughs and can concentrate the sun ‘s energy to about 30 times its normal intensity.
Concentrated solar power plants were first developed in the 1980s. The largest facility in the world is a series of plants in California’s Mojave Desert. This Solar Energy Generating System (SEGS) generates more than 650 gigawatt-hours of electricity every year.
- Other large and effective plants have been developed in Spain and India.
- Concentrated solar power can also be used on a smaller scale.
- It can generate heat for solar cookers, for instance.
- People in villages all over the world use solar cookers to boil water for sanitation and to cook food.
- Solar cookers provide many advantages over wood-burning stoves: They are not a fire hazard, do not produce smoke, do not require fuel, and reduce habitat loss in forests where trees would be harvested for fuel.
Solar cookers also allow villagers to pursue time for education, business, health, or family during time that was previously used for gathering firewood. Solar cookers are used in areas as diverse as Chad, Israel, India, and Peru. Solar Architecture Throughout the course of a day, solar energy is part of the process of thermal convection, or the movement of heat from a warmer space to a cooler one.
- When the sun rises, it begins to warm objects and material on Earth.
- Throughout the day, these materials absorb heat from solar radiation.
- At night, when the sun sets and the atmosphere has cooled, the materials release their heat back into the atmosphere,
- Passive solar energy techniques take advantage of this natural heating and cooling process.
Homes and other buildings use passive solar energy to distribute heat efficiently and inexpensively. Calculating a building’s ” thermal mass ” is an example of this. A building’s thermal mass is the bulk of material heated throughout the day. Examples of a building’s thermal mass are wood, metal, concrete, clay, stone, or mud.
- At night, the thermal mass releases its heat back into the room.
- Effective ventilation systems—hallways, windows, and air ducts—distribute the warmed air and maintain a moderate, consistent indoor temperature.
- Passive solar technology is often involved in the design of a building.
- For example, in the planning stage of construction, the engineer or architect may align the building with the sun ‘s daily path to receive desirable amounts of sunlight,
This method takes into account the latitude, altitude, and typical cloud cover of a specific area. In addition, buildings can be constructed or retrofitted to have thermal insulation, thermal mass, or extra shading. Other examples of passive solar architecture are cool roofs, radiant barriers, and green roofs,
- Cool roofs are painted white, and reflect the sun ‘s radiation instead of absorbing it.
- The white surface reduces the amount of heat that reaches the interior of the building, which in turn reduces the amount of energy that is needed to cool the building.
- Radiant barriers work similarly to cool roofs.
They provide insulation with highly reflective materials, such as aluminum foil. The foil reflects, instead of absorbs, heat, and can reduce cooling costs up to 10%. In addition to roofs and attics, radiant barriers may also be installed beneath floors.
Green roofs are roofs that are completely covered with vegetation, They require soil and irrigation to support the plants, and a waterproof layer beneath. Green roofs not only reduce the amount of heat that is absorbed or lost, but also provide vegetation, Through photosynthesis, the plants on green roofs absorb carbon dioxide and emit oxygen.
They filter pollutants out of rainwater and air, and offset some of the effects of energy use in that space. Green roofs have been a tradition in Scandinavia for centuries, and have recently become popular in Australia, Western Europe, Canada, and the United States.
For example, the Ford Motor Company covered 42,000 square meters (450,000 square feet) of its assembly plant roofs in Dearborn, Michigan, with vegetation, In addition to reducing greenhouse gas emissions, the roofs reduce stormwater runoff by absorbing several centimeters of rainfall. Green roofs and cool roofs can also counteract the ” urban heat island ” effect.
In busy cities, the temperature can be consistently higher than the surrounding areas. Many factors contribute to this: Cities are constructed of materials such as asphalt and concrete that absorb heat; tall buildings block wind and its cooling effects; and high amounts of waste heat is generated by industry, traffic, and high populations.
- Using the available space on the roof to plant trees, or reflecting heat with white roofs, can partially alleviate local temperature increases in urban areas.
- Solar Energy and People Since sunlight only shines for about half of the day in most parts of the world, solar energy technologies have to include methods of storing the energy during dark hours.
Thermal mass systems use paraffin wax or various forms of salt to store the energy in the form of heat. Photovoltaic systems can send excess electricity to the local power grid, or store the energy in rechargeable batteries. There are many pros and cons to using solar energy,
Advantages A major advantage to using solar energy is that it is a renewable resource, We will have a steady, limitless supply of sunlight for another 5 billion years. In one hour, the Earth’s atmosphere receives enough sunlight to power the electricity needs of every human being on Earth for a year.
Solar energy is clean. After the solar technology equipment is constructed and put in place, solar energy does not need fuel to work. It also does not emit greenhouse gases or toxic materials. Using solar energy can drastically reduce the impact we have on the environment.
- There are locations where solar energy is practical,
- Homes and buildings in areas with high amounts of sunlight and low cloud cover have the opportunity to harness the sun ‘s abundant energy.
- Solar cookers provide an excellent alternative to cooking with wood-fired stoves—on which 2 billion people still rely.
Solar cookers provide a cleaner and safer way to sanitize water and cook food. Solar energy complements other renewable sources of energy, such as wind or hydroelectric energy, Homes or businesses that install successful solar panels can actually produce excess electricity.
These homeowners or businessowners can sell energy back to the electric provider, reducing or even eliminating power bills. Disadvantages The main deterrent to using solar energy is the required equipment. Solar technology equipment is expensive. Purchasing and installing the equipment can cost tens of thousands of dollars for individual homes.
Although the government often offers reduced taxes to people and businesses using solar energy, and the technology can eliminate electricity bills, the initial cost is too steep for many to consider. Solar energy equipment is also heavy. In order to retrofit or install solar panels on the roof of a building, the roof must be strong, large, and oriented toward the sun ‘s path.
Both active and passive solar technology depend on factors that are out of our control, such as climate and cloud cover, Local areas must be studied to determine whether or not solar power would be effective in that area. Sunlight must be abundant and consistent for solar energy to be an efficient choice.
In most places on Earth, sunlight ‘s variability makes it difficult to implement as the only source of energy. Fast Fact Agua Caliente The Agua Caliente Solar Project, in Yuma, Arizona, is the world’s largest array of photovoltaic panels. Agua Caliente has more than 5 million photovoltaic modules, and generates more than 600 gigawatt-hours of electricity.
- Fast Fact Green Chicago Millennium Park in Chicago, Illinois, has one of the most expansive green roofs in the worldalmost 100,000 square meters (more than a million square feet).
- Vegetation at ground level covers 24.5 acres of an underground parking garage, and includes gardens, picnic areas, and an outdoor concert facility.
Fast Fact Solar Decathlon The Solar Decathlon is a biannual international event presented by the U.S. Department of Energy. Teams compete to design, build, and operate the most attractive, effective, and energy-efficient solar-powered house. A team from the University of Maryland won the 2011 contest, and the next Solar Decathlon will be held in 2013,
What is solar energy and how does it work?
How does solar power work? Solar power works by converting energy from the sun into power. There are two forms of energy generated from the sun for our use – electricity and heat. Both are generated through the use of solar panels, which range in size from residential rooftops to ‘solar farms’ stretching over acres of rural land.
How do solar panels work without batteries?
Hybrid Systems: When a Battery is Most Useful – Using solar panels without battery storage is a viable option for most people. However, a battery backup system might come in handy the most for people who live in areas with:
An unreliable power grid A lot of natural disasters Frequent Public Safety Power Shutoffs (PSPS)
If you simply like the idea of being completely independent of the grid or using 100% clean energy, a battery is probably your answer. While it would be nice to only pull your own clean energy back from the grid, that’s not necessarily how it works. When you pull grid power, it’s from a general pool, which could include sources from fossil fuel plants.
How is solar power used?
Seven Uses of Solar Energy FAQs – The main uses of solar energy are solar photovoltaics (PV) for electricity, solar heating and cooling (SHC) and concentrated solar power (CSP). People primarily use SHC systems for heating or cooling water and spaces (like your home).
- CSP systems use reflective devices to concentrate the sun’s energy and are mainly marketed to utilities.
- The five main uses of solar energy are solar electricity, solar water heating, solar heating, solar ventilation and solar lighting.
- There are more uses for solar energy, but homes and businesses typically use solar energy for these purposes.
The uses of solar energy include solar electricity, solar water heating, solar heating, solar ventilation, solar lighting, portable solar (for personal electronic devices) and solar transportation (for electric vehicles ). China uses the most solar energy,
The country has the largest solar fleet installation, which generates about 205 GW of power. By 2060, China aims to fully neutralize its carbon emissions. The sun creates two main types of solar energy, light and heat, which people can harness in a variety of ways. For example, some electric vehicles (EVs) use solar photovoltaic (PV) energy to charge their batteries instead of relying on gasoline.
Another example is using a solar water heater to heat the water in your swimming pool or the water you use in your house through a sink faucet or shower. Solar energy is used across the U.S., but it’s most prominent in the states of California, Texas and North Carolina.
- California uses the most solar energy by far, with over 29,000 megawatts of electricity produced in 2020 alone.
- This is partly due to a 2018 California law requiring single- and multi-family homes, as well as commercial buildings, to install solar panels starting in 2020.
- The five main advantages of solar energy include saving money on your monthly energy bill, improving local air quality, increasing your home’s resale value, making the electric grid more resilient and providing a path for you to be energy independent,
Solar is the best energy solution because it’s fully renewable, unlike traditional power. This means it’s available every day, and people anywhere in the world can harness it. Solar energy is abundant, and it benefits the environment and public health by substantially reducing carbon emissions.
Solar projects also make better use of underutilized land, such as through agrivoltaic farming, The four main advantages of solar energy are that it reduces your monthly utility bill substantially, improves air quality thanks to zero carbon emissions, improves your home’s resale value and reduces reliance on local grids.
Solar energy is radiant heat and light from the sun that people harness using a variety of technologies. The benefits of solar power include lower monthly electricity bills, improved local air quality and higher home resale values, It also makes the electric grid more resilient, provides a hedge on rising energy costs and offers energy independence,
Solar helps the environment by reducing carbon and methane emissions and decreasing ground and air pollution. Solar also helps decrease water usage and doesn’t pollute the ground, rivers or any natural waterbodies. A solar ventilation system is a transpired solar collector or solar wall that heats air before it enters a building or other structure.
Solar ventilation systems are a sustainable and efficient way of lowering a building’s energy consumption and costs through renewable sources. People source solar energy entirely from the sun. They can harness it in a variety of ways, using technologies such as solar photovoltaic (PV), solar thermal and solar heating.
How is solar energy used today?
Solar energy is a powerful source of energy that can be used to heat, cool, and light homes and businesses. Text version More energy from the sun falls on the earth in one hour than is used by everyone in the world in one year. A variety of technologies convert sunlight to usable energy for buildings.
The most commonly used solar technologies for homes and businesses are solar photovoltaics for electricity, passive solar design for space heating and cooling, and solar water heating. Businesses and industry use solar technologies to diversify their energy sources, improve efficiency, and save money.
Energy developers and utilities use solar photovoltaic and concentrating solar power technologies to produce electricity on a massive scale to power cities and small towns. Learn more about the following solar technologies:
Why solar energy is good for the environment?
How Does Solar Energy Interact with Wildlife and the Environment? – As a renewable source of power, solar energy has an important role in reducing greenhouse gas emissions and mitigating climate change, which is critical to protecting humans, wildlife, and ecosystems.
- Solar energy can also improve air quality and reduce water use from energy production.
- Because ground-mounted photovoltaics (PV) and concentrating solar-thermal power installations require the use of land, sites need to be selected, designed, and managed to minimize impacts to local wildlife, wildlife habitat, and soil and water resources.
The U.S. Department of Energy (DOE) Solar Energy Technologies Office (SETO) supports research to better understand how solar energy installations, wildlife, and ecosystems interact and to identify strategies that maximize benefits to the local environment.
Why the solar energy is important?
1. Solar Power Is Good for the Environment – The most commonly known fact about solar energy is that it represents a clean, green source of energy, Solar power is a great way to reduce your carbon footprint, There’s nothing about solar power that pollutes mother nature.
- Solar power doesn’t release any greenhouse gasses, and except for needing a source of clean water to function, it uses absolutely no other resources.
- Hence, it’s safe and environmentally-friendly.
- Yet, people are still in doubt why solar energy is good.
- Solar power is self-sufficient and installing solar panels on your roof is a safe and easy path to contribute to a sustainable future,
Starting on your home is a great way to show you care about the environment.