Light, at its most elemental core, is energy we see. This energy is delivered in massive amounts to the surface of the Earth because of the Sun, making it available for us to capture, store, and use within a solar energy system. In this article, we will look at how light interacts with photovoltaic technology—learning what photovoltaics is and how it works—to bring solar power into our homes.
What is Photovoltaics?
Photovoltaic solar panels convert sunlight into electricity using the photovoltaic effect. This is the specific process where voltage is generated in a photovoltaic cell when exposed to sunlight.
To generate the photovoltaic effect two types of semiconductive materials (n-type and p-type) are joined together to create a p-n junction. Sunlight strikes and transfers energy from the sun’s photons to the electrons of the n-type material and creates a conduction band between it and the p-type material. This process generates electricity.
How Do PV Solar Panels Work?
PV solar panels consist of multiple solar cells which are made of semiconductor materials, like silicon. These solar cells generate an electric current when they absorb photons. This electricity is direct current (DC), which is not compatible with most household appliances and devices. To make this power useful, a solar system converts the generated DC current to alternating current (AC) electricity through an inverter—a device which changes the direction and frequency of the electric current. The AC current can then be used to power your home or sent to the utility grid through a net meter.
Some homeowners may also choose to install a home storage system such as a battery or generator, which can store excess solar power for later use. This can provide backup electricity or reduce reliance on the utility grid during peak hours when energy prices are higher or during emergencies.
The Science Behind Photovoltaics
In addition to the photovoltaic effect, PV solar panel technology also relies on a number of other scientific concepts.
Light absorption and emission are two important processes in solar technology.
- Light absorption is the process in which optical energy is converted to internal energy of electrons, atoms, or molecules.
- Light emission is the process of converting the internal energy of electrons, atoms, or molecules to optical energy.
These processes can be used to harvest solar energy, generate light, and study the properties of materials.
Light transmission and reflection, related to absorption and emission, affect how solar energy interacts with Earth’s surface and atmosphere.
- Transmission is the passage of solar radiation through a medium, such as air, water, or glass.
- Reflection is the bouncing of solar radiation off a surface, such as snow, ice, or metal.
Both transmission and reflection can change the amount and direction of solar energy which reaches different parts of the surface of our planet. Transmission and reflection are both important for solar technology because they determine how much solar energy can be captured and converted into electricity or heat by various devices, such as PV solar panels. For example, PV solar panels are designed to have high transmission of solar radiation and low reflection so they can absorb as much sunlight and to convert it into electricity.
History of PV Solar Panel Technology
The power of photovoltaics was first discovered by Alexandre Edmond Becquerel, a French physicist who observed the photovoltaic effect in 1839. By immersing two metal electrodes connected to a galvanometer in an electrolytic solution he saw an increase in current when the electrodes were exposed to light.
This power was harnessed in the first practical solar cell made by Charles Fritts, an American inventor who coated selenium with a thin layer of gold, in 1883. He achieved a conversion efficiency of about 1%. This means 1% of the sunlight was converted into electricity.
The first modern solar cell was made by Bell Labs in 1954, using silicone instead of selenium. They achieved an efficiency of about 6%—much higher than Fritts’ initial attempts. These achievements were just the beginning, and the field has continued to grow and develop.
Modern Advances in PV Solar Panel Technology
Since the creation of the first practical solar cell, the efficiency of solar technology has improved significantly. This efficiency depends on several factors, such as the type and quality of the material, the design and structure of the cell, and local conditions.
The highest efficiency recorded for a single-junction solar cell was 29.15%, achieved by Fraunhofer ISE in 2020 using gallium arsenide as the material. The highest efficiency for a multi-junction solar cell was 47.1%, achieved by NREL in 2019 using six different materials.
In typical residential solar systems, homeowners can expect efficiency rates ranging from 16-25% as manufacturers balance efficiency with cost effectiveness. These efficiency rates offer lots of opportunity to generate the power required to meet—and exceed—your energy needs and save on your electrical bill.
Using PV Solar Panels to Power Your Home
With your fuller understanding of what photovoltaics is and how it works, you can now put this technology to work for you in your home. Adding PV solar panels on your home allows you to make the switch to renewable energy, save on your monthly electricity bill, and reduce the demand for energy produced through fossil fuels, helping protect the environment.
At Blue Raven Solar, our solar experts are here to help you navigate the evolution and advancement of PV solar technologies, bringing you the best solar energy solutions to match your household needs. As a reputable, end-to-end, local solar installer, we make the process simple and hassle-free at each step. Reach out to talk with a Blue Raven Solar specialist about going solar today.