Solar energy is the most abundant energy resource on Earth. It can be captured and used in several ways, and as a renewable energy source, is an important part of our clean energy future.
Solar energy: what is it and how does it work?
The sun does more than for our planet than just provide light during the daytime – each particle of sunlight (called a photon) that reaches Earth contains energy that fuels our planet. Solar energy is the ultimate source 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.
Where does all of this energy come from? Our sun, like any star in the galaxy, is like a massive nuclear reactor. Deep in the Sun’s core, nuclear fusion reactions produce massive amounts of energy that radiates outward from the Sun’s surface and into space in the form of light and heat.
Solar power can be harnessed and converted to 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 figures to play an important part in the global energy future.
Harnessing solar energy for usable power
There are many ways to use energy from the sun. 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), and 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 panel technology improving each year, the economic benefits of solar improve, adding to the environmental perks of choosing a clean, renewable energy source.
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 convert sunlight right into electricity that can be used immediately, stored in a solar battery, or sent to the electric grid for credits on your electric bill.
Solar panels convert solar energy into usable electricity through a process known as the photovoltaic effect. Incoming sunlight strikes a semiconductor material (typically silicon) 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 must be converted to alternating current (AC) electricity using a solar inverter. This conversion is necessary because the U.S. electric grid operates using AC electricity, as do most household electric appliances.
Solar energy can be captured at many scales using photovoltaics, and installing solar panels 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 can power company operations or supply energy to the electric grid.
A second way to use solar energy is to capture the heat from solar radiation directly and use that heat in a variety of ways. Solar thermal energy has a broader range of uses than a photovoltaic system, but using solar thermal energy for electricity generation at small scales is not as practical as using photovoltaics.
There are three general types of solar thermal energy used: low-temperature, used for heating and cooling; mid-temperature, used for heating water; and high-temperature, used for electrical power generation.
Low-temperature solar thermal energy systems involve heating and cooling air as a means of climate control. An example of this type of solar energy usage is 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 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 solar thermal energy systems are used for generating 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 can then be used to turn water into steam, which then can turn a turbine and generate electricity. This type of technology is often referred to as concentrated solar power.
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 Solar Marketplace. After signing up, you will receive free solar quotes from qualified, pre-vetted solar installers near you. Looking at quotes in our apples-to-apples setup is a great way to understand offers and compare key metrics such as energy needs met and cost per watt.