When you think of solar power, you may think of those ubiquitous, blue solar panels. These are technically called photovoltaic systems – what a mouthful!
In this article, we’ll explain the basics of photovoltaic panels and how they work to gather sunlight and convert it into usable energy.
Solar Panels Aren’t the Only Type of Solar Power
First, remember that photovoltaic cells aren’t the only way to gather and use solar energy. We often forget that solar power encompasses more than just flat blue photovoltaic panels.
Beyond solar photovoltaic systems (called PV systems for short), we have the following:
1. Concentrated Solar Power
Concentrated solar power does not use photovoltaic solar panels. Instead, mirrors or reflectors are used to “concentrate” the hot solar energy to a small area, where it is converted to electricity. Typically, a steam engine might be used to convert the hot sunlight into electric power.
2. Solar Thermal Energy
Solar thermal energy systems gather the heat from the sun and either use it generate electricity or to heat buildings or structures such as swimming pools. A solar hot water heater is using solar thermal energy to heat water instead of gas or electric.
3. Passive Solar Heating
Passive solar heating is quite simple and often happens without planning. The sun heating up your car as it sits outside is an example of passive solar heating.
Obviously, this type of solar heating can happen without design or intent. However, the best passive solar heating systems take advantage of the sun’s energy to heat buildings and reduce electricity costs. Certain types of architectural designs and building materials can facilitate passive solar heating.
How Photovoltaic Systems Work
As you can guess, photovoltaic systems are the most technically complex of the types of solar energy available. Yet, they are also simple on a basic level.
Each solar panel is made up of individual photovoltaic cells, also known as solar cells. A group of solar cells makes up a solar module (or panel). A group of modules can be connected to create a solar array.
These solar cells directly convert light into electricity, and they do it at the atomic level.
A solar cell is made up of a semiconductor that can transmit electricity. The reason it is called a “semi” conductor is that while it conducts electricity, it is not as much electricity as with a full conductor. This makes it easier to control the electrical current.
The semiconductor layer is treated to create an electrical field, where one side is positively charged, and the other side is negatively charged. By connecting electrical conductors to both the positively and negatively charged material, an electric circuit is created.
When light hits the cell, electrons are released from the atoms of the semiconductor. These electrons then travel through the conductors, and voila, we have electricity.
If this still does not make sense, don’t worry. All you need to know is that the sunlight activates electrons to create an electric current.
Of course, the more solar cells you have, the more current you will create.
Photovoltaic Systems Keep Getting Bigger and Better
PV systems can work on a large or small scale. You may have seen solar panels on the roof of a local home or business. They run on the same underlying technology as a large-scale photovoltaic power plant, also called a solar park.
The difference is simply the number of solar panels used to collect the solar energy and convert it into electricity. More and more large-scale solar parks are being built. India currently has the world’s largest solar power plant with a capacity for 648 MW (megawatts), and it covers an area of 10 square kilometers.
Previous, the United States touted Agua Caliente, located in Yuma County, Arizona, as the largest solar photovoltaic power station on the planet. That plant generates 290 MW.
China is also a major producer of solar power, and has been building more floating photovoltaic power facilities where the solar panels float on water. They are currently building a 150 MW floating solar power station in Huainan, Anhui Province.
Solar Photovoltaic Panel Use Will Continue to Grow
As fossil fuels become more expensive and difficult to extract from the earth, renewable energy sources will continue to grow in popularity. Solar panels using photovoltaic technology will continue to be major sources of renewable energy in the years to come. As the panels become more energy efficient, and the prices drop, more everyday home owners will be installing panels on rooftops. Meanwhile, more and more countries such as China, India, and the United States are finding creative ways to create solar power plants, whether on land or on water.