Simply put, solar energy is energy from the sun. It’s the most abundant energy resource on Earth and can be converted from radiant energy from the sun to electrical or thermal energy. We use solar energy for many purposes, such as powering and heating homes, businesses, utilities, and more. Solar power is a renewable resource and, as such, is a critical part of our clean energy future. In this article, we’ll explain what you need to know about solar energy, including how it works and its applications.
Key takeaways about solar energy
- Solar energy is energy from the sun and is captured with various technologies, including solar panels.
- There are two main types of solar energy: photovoltaic and thermal.
- The “photovoltaic effect” is the mechanism by which silicon solar panels harness the sun’s energy and generate electricity.
- Want to take advantage of solar energy yourself? Join the EnergySage Marketplace to compare solar quotes for your property.
In this article:
- The photovoltaic effect
- What is solar used for?
- Photovoltaic solar energy
- Solar thermal energy
- FAQs about solar energy
The photovoltaic effect
The sun does more for our planet than just provide light during the daytime – each particle of sunlight (called a photon) that reaches Earth’s surface contains energy that fuels our planet. Solar energy is ultimately responsible for all of our weather systems and energy sources on Earth, and enough solar radiation hits the surface of the planet each hour to theoretically fill our global energy needs for nearly an entire year.
So where does all of this energy come from? Our sun, like any star in the galaxy, is basically a massive nuclear reactor. Deep in the Sun’s core, nuclear fusion reactions produce huge amounts of energy that radiates outward from the sun’s surface and into space in the form of light and heat.
On Earth, we harness and convert solar power from the sun into usable energy using photovoltaics or solar thermal collectors. Although solar energy only accounts for a small amount of overall global energy use, the falling cost of installing solar panels means that more and more people in more places can take advantage of solar energy. Solar is a clean, renewable energy resource and will play an important part in the global energy future.
What is solar power used for?
There are many solar energy technologies that harness the sun’s energy. The two main ways to use energy from the sun are photovoltaics and solar thermal capture. Photovoltaics are much more common for smaller-scale electricity projects (like residential solar panel installations), while solar thermal capture is typically only used for electricity production on massive scales in utility solar installations. In addition to producing electricity, lower temperature variations of solar thermal projects can be used for heating and cooling.
Solar is one of the fastest-growing and cheapest sources of power in the world and will continue to spread rapidly in the coming years. With solar technology improving each year, the economic benefits of solar improve, adding to the environmental perks of choosing a clean, renewable energy source. In the coming years, we can expect more and more solar and wind power to enter the mix of large-scale power stations, helping to reduce our country’s greenhouse gas emissions and combat climate change.
Photovoltaic solar energy
A common way for property owners to take advantage of solar energy is with a photovoltaic (PV) solar system. With a solar PV system, solar panels (also called solar modules) convert sunlight into electricity that you can use immediately, store in a solar battery, or send to the electric grid for credits on your electric bill (depending on where you live).
Solar panels convert solar energy into usable electricity through a process known as the photovoltaic effect. Incoming sunlight strikes a semiconductor material (typically silicon) in solar cells and knocks electrons loose, setting them in motion and generating an electric current that can be captured with wiring. This current is known as direct current (DC) electricity and needs to be converted to alternating current (AC) electricity using a solar inverter – this is because most of the U.S. electric grid operates using AC electricity, as do most household electric appliances.
Solar energy is captured at many scales using photovoltaics, and installing a solar energy system is a smart way to save money on your electric bill while reducing your dependence on nonrenewable fossil fuels. Large companies and electric utilities can also benefit from photovoltaic solar energy generation by installing large solar arrays that power company operations or supply energy to the power grid.
Storing energy with solar batteries
Solar electricity is great when the sun is shining – but if you want to maximize your grid independence, you’ll need a solar-plus-storage system. With a solar battery, you can charge your battery with excess energy generated by your system, rather than exporting that energy to the grid. Then, at night or if there’s inclement weather, you can use this stored energy to minimize how much electricity you pull from the grid. If you size your solar-plus-storage system accordingly, you can also go “off the grid” – but, unless your electricity consumption is low, you should expect this setup to be quite complicated and expensive!
Solar thermal energy
A second way to use solar energy is to capture the heat from solar radiation directly and use that heat as solar thermal energy. Solar thermal energy has a broader range of uses than a photovoltaic system, but using it for electricity generation at small scales isn’t as practical as using photovoltaics.
There are three general types of solar thermal energy: low-temperature used for heating and cooling, mid-temperature used for heating water, and high-temperature used for electrical power generation.
Low-temperature
Low-temperature solar thermal energy systems involve heating and cooling air as a means of climate control, such as in passive solar building design. In properties built for passive solar energy use, the sun’s rays are allowed into a living space to heat an area and blocked when the area needs to be cooled.
Mid-temperature
Mid-temperature solar thermal energy systems include solar hot water heating systems. In a solar hot water setup, heat from the sun is captured by collectors on your rooftop. This heat is then transferred to the water running through your home’s piping so you don’t have to rely on traditional water heating methods, such as water heaters powered with oil or gas.
High-temperature
High-temperature solar thermal energy systems use concentrated solar power (CSP) to generate electricity on a larger scale. In a solar thermal electricity plant, mirrors focus the sun’s rays on tubes containing a liquid that can hold heat energy well. This heated fluid evaporates water into steam, which then turns a turbine and generates electricity –all using concentrated sunlight!
Solar heating and cooling with heat pumps
As we’ve discussed, you can heat your home or hot water with solar thermal energy –but you can also do so with solar photovoltaic energy by pairing your solar energy system with a heat pump! Instead of generating heat (like in a natural gas or oil heating system), heat pumps work by simply transferring heat from one place to another, allowing them to have high energy efficiency. If you don’t have solar, you can still power heat pumps with electrical energy from the grid, but you’ll save the most by running them on free solar energy produced right at home! Learn more about how to size your solar system to support a heat pump.
Frequently asked questions about solar power
There’s a lot to learn about solar energy – here are a few quick answers to common questions.
How does solar energy work?
Solar power generation starts when solar panels absorb photons, or particles of light, with photovoltaic cells, generating this direct current (DC) energy and then converting it to usable alternating current (AC) energy with the help of inverter technology. AC energy then flows through the home’s electrical panel and is distributed accordingly.
What is solar power used for?
Solar power is used in two main ways: generating electricity (like with rooftop solar panels) or generating thermal energy (like with concentrated solar power plants). For most homeowners, solar panels that convert solar energy to electricity is the best use of solar energy because it allows them to save on electric bills.
How long do solar panels last?
Solar panels usually last for 25 to 30 years before they start to see steeper drops in performance than is useful for many homes. For those almost three decades, however, you’ll be generating free solar electricity from the sun.
How to support solar development
The percentage of renewable energy (including solar) in your utility’s energy mix continues to increase – but significant strides won’t happen overnight. In the meantime, you can support the development of solar farms in your community by subscribing to a community solar farm! Community solar is a great option if you’re a renter or don’t have a good house for solar; it leads to local job creation and will save you between 10 to 15 percent annually on your electric bills. Browse community solar projects near you.
Take advantage of solar energy on your property
The best way for individual property owners to save money with solar energy is to install a home solar photovoltaic system. To find the right system for the right price, you should shop on the EnergySage Marketplace. After signing up, you’ll receive free solar quotes from qualified, pre-vetted solar installers near you. Looking at quotes is a great way to understand offers and compare key metrics such as energy needs met and cost per watt –and, if you just want to explore how much a solar power system might cost, be sure to check out our solar calculator.
FAQs
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.
What is the difference between solar energy and solar power? ›
Solar power is energy from the sun that is converted into thermal or electrical energy. Solar energy is the cleanest and most abundant renewable energy source available, and the U.S. has some of the richest solar resources in the world.
What is solar energy explained for kids? ›
Solar cells use the Sun's light rather than its heat. When the Sun shines on a solar cell, the cell turns the light energy into electricity. A single solar cell makes only a little electricity. However, groups of solar cells can provide electricity for whole buildings.
What are the 3 types of solar power? ›
Solar Power System types, On-Grid, Off-Grid, Hybrid Solar System.
What are the 4 main types of solar energy? ›
Passive solar gain. Solar thermal (for heating) Concentrated solar power (for electricity) Solar Photovoltaics (electricity)
What are the 2 main types of solar energy? ›
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).
What are 3 pros and cons of solar energy? ›
Pros and Cons of Solar Energy
| Advantages of Solar Energy | Disadvantages of Solar Energy |
|---|
| Reduces Electricity Bills | Weather Dependent |
| Diverse Applications | Solar Energy Storage is Expensive |
| Low Maintenance Costs | Uses a Lot of Space |
| Technology Development | Associated with Pollution |
1 more rowOct 7, 2022
Disadvantages of Solar Energy
- The high initial costs of installing panels. The most commonly cited solar energy disadvantage, cost, is declining as the industry expands. ...
- Solar energy storage is expensive. ...
- Solar doesn't work for every roof type. ...
- Solar panels are dependent on sunlight.
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.
What is the solar system simple words? ›
A solar system is a group of planets and other bodies that revolve around a star. The Earth is in a solar system with seven other planets and some other orbiting objects — including Pluto (who was kicked out of the planet club in 2006).
Amazingly, close to 20 manufacturers at SNEC 2020 showcased panels rated over 600W, with the most powerful being the Jumbo 800W module from JA solar.
What are the benefits of solar energy? ›
Each kilowatt-hour (kWh) of solar that is generated will substantially reduce greenhouse gas emissions like CO2, as well as other dangerous pollutants such as sulfur oxides, nitrogen oxides and particulate matter. Solar also reduces water consumption and withdrawal.
What are 4 benefits of solar power explain? ›
Renewable clean power that is available every day of the year, even cloudy days produce some power. Return on investment unlike paying for utility bills. Virtually no maintenance as solar panels last over 30 years. Creates jobs by employing solar panel manufacturers, solar installers, etc.
How efficient is solar energy? ›
How efficient are solar panels? The efficiency of solar panels has improved dramatically in recent years, from an average of around 15% conversion of sunlight to usable energy to around 20%. High-efficiency solar panels can reach as much as nearly 23%.
What is solar energy also known as? ›
Solar radiation, often called the solar resource or just sunlight, is a general term for the electromagnetic radiation emitted by the sun. Solar radiation can be captured and turned into useful forms of energy, such as heat and electricity, using a variety of technologies.
What is the main source of solar energy? ›
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.
What is the best type of solar energy? ›
Monocrystalline solar panels are one of the most popular solar panel choices. This type of panel currently features the highest efficiency rate, at an average of 24%, and its average lifespan of 25 to 40 years is longer than other solar panels.
What country has most solar energy? ›
China- 340 GW
China's solar prowess is staggering. With a whopping 340 GW, the country is the largest producer of solar energy in the world. In the first six months of 2022, the nation has deployed more than 30.88 GW of Solar PV systems.
Can you run a house on solar power alone? ›
Can a house run on solar power alone? It is possible to run a house on solar power alone. However, going completely off-grid requires a considerable financial and time investment. The higher your energy requirements, the more solar panels you'll need.
Will solar panels reduce my electric bill? ›
Cut your electricity bills
Sunlight is free, so once you've paid for the initial installation, your electricity costs will be reduced. Find out how much you could save by using the Solar Energy Calculator.
According to the Energy Saving Trust, solar panels will generate around a 5th of their usual energy production in the winter months. During the depths of a wintery month, on average you will get around one hour of full power output. With your panels still continuing to generate electricity for you!
Do solar panels affect home insurance? ›
You may not see an increase in your homeowners insurance premium after installing solar panels on your roof. However, you'll likely need to raise your coverage limits to account for the replacement cost of your solar panels, which will likely result in some increase to your premium.
Do solar panels make your house hotter? ›
According to a study conducted by researchers at UC San Diego Jacobs School of Engineering, solar panels reduced the amount of heat reaching the roof by an incredible 38%, keeping a building's roof 5 degrees cooler than portions of a roof exposed to sunlight directly.
Are solar panels worth it for seniors? ›
Solar panels are definitely worth it for seniors. If you can purchase your system outright, you see the biggest savings overall. However, with a $0-down, low-interest solar loan, your monthly payments will typically be lower than your electricity bill, allowing you to see savings on day one.
What are three facts about solar? ›
Fact #1: Solar power is the most abundant source of energy on the planet. Fact #2: More solar energy reaches Earth in one hour than the world uses all year. Fact #3: Sunlight takes approximately eight minutes to reach the Earth.
What is the solar system answer in one sentence? ›
A solar system is a collection of the Sun, eight planets and their moons, comets, asteroids, meteoroids, and dwarf planets revolving around the Sun.
Why is the solar system important? ›
The Solar System provides the only known example of a habitable planet, the only star we can observe close-up, and the only worlds we can visit with space probes. Solar System research is essential for understanding the origin and evolution of planets, along with the conditions necessary for life.
What is the solar system made of? ›
Our solar system is made up of a star—the Sun—eight planets, 146 moons, a bunch of comets, asteroids and space rocks, ice, and several dwarf planets, such as Pluto. The eight planets are Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. Mercury is closest to the Sun. Neptune is the farthest.
How much solar power do you need to run a house? ›
How many solar panels does it take to power a house? Based on average electricity consumption and peak sun hours, it takes around 17 400-Watt solar panels to power a home. However, this number will vary between 13-19 based on how much sun the panels get and how much electricity the home uses.
Can a house run 100% solar? ›
With a modern solar energy system, including power storage, you can definitely run a whole house completely on solar power. Today's high-efficiency solar panels and solar batteries make it cheaper than ever before to power an entire home exclusively using solar energy.
You'll be generating 1.8 kWh per panel per day. To meet the average requirement of 29.33 kWh of electricity per day for your household, then, you'll need 17 solar panels.
What is the difference between power and energy? ›
Energy is the capacity to do some physical activities or work, such as running, jumping, etc., while power is defined as the rate at which the energy is transferred, or the work is completed. The unit used to measure energy is joules, ergs and calories. Power is measured in watts.
What are the 5 types of solar energy? ›
Learn more about the following solar technologies:
- Solar Photovoltaic Technology. Converts sunlight directly into electricity to power homes and businesses.
- Passive Solar Technology. ...
- Solar Water Heating. ...
- Solar Process Heat. ...
- Concentrating Solar Power.
– it's because the solar panels we have can only generate electricity when it's a clear sunny day. In order for a home or business to rely entirely on solar power, the owners would need to live in a sunny area and use batteries to store excess energy for cloudy and rainy days.
Is solar power a good 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.
