What is Solar Energy?
Being from the sun, solar energy is the most abundant and ‘green’ energy source that can be used to power the globe. It is a renewable energy source, and the only downside is that it cannot be harnessed when there is no sunlight, such as if it is a cloudy day or in regions that are more used to heavy rainfall with cloud cover. Solar energy works by capturing the energy emitted from the sun and turning that energy into electricity. It is a vital key aspect of our greener, cleaner energy future and can be captured and harnessed for use in several ways.
What if I told you that every hour, the sun releases packets of energy called photons that travel a huge distance (93 million miles) to earth in 8.5 minutes. And to make it even better, every hour enough of these photons have the capability to generate enough energy to satisfy the quota for energy needs globally, for an entire year. The sun is a natural nuclear reactor, without all the harmful effects on our planet.
Our ability to harness the sun’s power and convert it into usable energy is on the rise. The more that technology advances, the more that the cost of solar energy is decreasing. Photovoltaic power only accounts for only five-tenths of 1% of the energy consumed in the United States, but that is bound to increase in the future. Based on a report back in 2017 from the International Energy Agency, solar has become the world’s fastest-growing source of power, and this is from a renewable source.
This marks the point in time that solar energy’s growth has grown past all other fuel sources. This means that we will work towards a clean energy source from utilizing the sun’s power in the coming years.
Solar Energy: What is it and How Does it Work?
Our sun does more for Earth and the people living on it than just providing light and warmth; each photon that reaches our planet contains energy that is essentially fuel for us. All of our weather systems and energy sources function appropriately due to the nature that our sun provides us. As stated above, there is enough solar radiation that hits Earth hourly to fill our energy needs for an entire year. As stated above, this energy from the sun is because it is a natural massive nuclear reactor. At its core, fusion reactions produce energy that radiates from the sun’s surface and into our atmosphere in the form of light and heat.
To get a little more technical, when photons hit a solar cell, they knock electrons loose from their atoms. This then forms an electrical circuit if conductors are attached to the positive and negative sides. After the electrical circuit is formed and electrons flow through it, they now generate electricity. You may have seen what is referred to as a solar panel on the side of a building or many in a field. These panels are made up of multiple cells, and multiple panels can be wired together to form a solar array. Of course, the more panels you have means more energy that is produced.
Solar thermal collectors, also referred to as photovoltaics can harness the collected solar power. Although solar energy doesn’t yet account for a lot of global energy usage, the cost of harnessing solar energy means that more people in more places will use it more widely. Solar is bound to play a role in our clean energy future because it is a clean, renewable energy source.
Harnessing Solar Energy for Usable Power
While there are many ways to utilize energy from the sun, the most common that we currently know of are photovoltaics and solar thermal capture. For smaller-scale electrical projects such as residential solar panel installation and use, photovoltaics are much more common. That said, solar thermal capture is primarily reserved for electricity production on massive scales in utility solar installations.
Lower temperature variations may also be used for heating and cooling.
In the next years, and many more to come, the use of solar power is projected to spread rapidly since it is one of the fastest-growing and budget-friendly sources of power available. Not to mention the fact that the technology behind solar panels and solar energy is only improving, with the economic benefits and environmental perks of choosing such a clean and renewable energy source.
What are Solar Panels Made of?
Like a battery, solar panels are made up of many solar cells; these cells are made of silicon, like semiconductors. They are constructed with a positive layer and a negative layer, which, as we know, together create an electric field.
Photovoltaic Solar Energy
Going off of the two main types of solar energy, the most common one used and the one that is used for property owners (such as homeowners) to take advantage of the clean energy that is solar energy, is with a photovoltaic (PV) solar system. With this type of solar energy, solar panels absorb energy from sun rays into electricity that can then be used in one of three ways: straight into your electrical grid, stored in a solar battery, or sent to the grid used by your electric company to then receive credits for. Installing solar panels is both a smart way to save money on your electric bill, as well as reduce our dependence on nonrenewable energy resources, such as fossil fuel.
Solar panels perform a process known as the photovoltaic effect, which converts solar energy into usable electricity. This is done by sunlight striking a semiconductor material (generally, this is silicon), which knocks electrons loose, allowing an electric current to be generated to be captured with the wiring.
This current is known as direct current (DC) and must be converted into alternating current (AC) electricity to be used, and this is done with a solar inverter. Both household electric appliances and the U.S. electric grid operate on AC electricity, so the DC electricity must be converted.
Solar Thermal
Above we went over photovoltaic solar energy; another way to utilize the sun’s power in the form of solar energy is to capture the heat from solar radiation and use that heat in a multitude of ways. Using solar thermal energy for electricity generation at small scales such as residential properties is not as practical as using photovoltaic solar energy since solar thermal energy has a broader range of use. When talking about solar thermal energy, it is important to note that there are three types: low-temperate, mid-temperature, and high-temperature.
- – Low-temperature systems control the temperature in a controlled environment, such as heating and cooling an indoor space. In this way, the sun’s rays are allowed into a living space, such as an apartment, to heat an area; or the rays are blocked off when the area needs to be cooled.
- –Mid-temperature systems are used for heating water in a hot water setup. The heat from the sun is collected by devices on your rooftop and is then transferred to the water that is already running through the water pipes in your home; this eliminates the need for a traditional water heater setup.
- –High-temperature systems are used to generate electricity on a much larger scale than for residential use; for instance, this type of system would be used in conjuncture with many solar panels, primarily on the ground. (Referred to as a thermal electricity plant). In this type of system, mirrors will be used to focus the sun’s rays on tubes containing a liquid that can absorb the ‘heat energy.’ The heated fluid then turns water into steam, thus turning a turbine and generating electricity.
How do Solar Panels Generate Electricity?
As stated above, solar panels generate DC electricity; from here, electrons flow in one direction around a circuit. For instance, we will use the example of a battery powering a light bulb. The electrons move from the negative side of the battery into the light and then back into the battery, in a constant energy flow.
AC (alternating current) electricity works a little differently; electrons are pushed and pulled, reversing direction, not unlike a cylinder found in a car engine. Generators create AC electricity when a coil of wire is spun next to a magnet. This type of electricity was the one chosen for the U.S power grid, and this is because it is less expensive to transmit over long distances. That said, solar panels create DC energy, so to use the energy created by solar panels, we must use an inverter.
What Does a Solar Inverter Do?
Because in the U.S, the electricity grids utilize AC electricity, a solar inverter is necessary to convert the DC energy that is produced from solar energy. A solar inverter does this by taking the DC electricity from the array into usable AC energy; think of it as the brain or CPU of the system. Additionally, solar inverters also provide ground fault protection and system readings, such as voltage, solar production, and PowerPoint tracking
. Related: Pros and Cons of Nuclear Energy
It is important to realize that there are two types of inverters: central inverters and micro-inverters. Central inverters have been around since the beginning of solar energy. Still, the introduction of micro-inverters has changed how solar energy is converted and is considered the updated technology. This is because micro-inverters optimize for each solar panel and not the solar system as a whole. What this optimization does is make sure that every solar panel is performing at optimal capacity.
Picture of a Microinverter:
It is also easier to diagnose any issues that may happen with a single panel. For instance, if there is an issue with the solar system, a central inverter will not pinpoint the trouble panel for a technician. Also, if one panel is not working, it can affect the whole system. However, with a micro-inverter, while a panel may be malfunctioning, your solar production will still be there but will be less.
How Does a Solar Panel System Work?
A solar panel system, our solar system, sounds a lot more complicated than it is. A solar system works by absorbing the sunlight that is cast on the panels on your roof. The panels then convert the sunlight into a DC, which then flows into the solar converter. From there, the solar converter converts the DC into AC electricity; and this is what you can use to power your home.
It is that simple; using the sun’s rays as a form of clean energy to power your home.
Now you may be wondering what would happen to the energy if you are not at home to reap the benefits? Or if it is a cloudy day, or there is no sunlight, such as at night? You still will benefit from having a solar system installed through a system called “net metering.” This system is in place because when you are producing, you produce more energy than what you would have used for, in most cases.
This excess energy is sent to the electric grid to be used elsewhere. You would then receive the credit from the electrical company for the excess energy that you sent to them. This credit can then be used to draw energy from the grid for energy use at night or on a cloudy day.
What Type of Energy is Solar?
Solar energy is a renewable energy source. Using N-type and P-type semiconductor material, solar panels change the rays from the sun into usable solar energy. Solar energy knocks electrons loose from their atoms when these absorb sunlight before mentioned materials. This process of converting light to electricity is called the photovoltaic (PV) effect. Solar panels currently convert most of the visible light spectrum and about half of the ultraviolet and infrared light spectrum to usable solar energy.
