Solar Panels 101: How Do Solar Photovoltaic Panels Work?
Every hour, sunbeams are able to generate electricity for the whole world for a full year reach the earth’s surface. With photovoltaics being the fastest-growing source of energy over the last few years, the future looks to be powered by photovoltaics.
Currently, over 3 million Americans are reaping the numerous benefits of solar panel electricity, and the number of people adopting solar solutions keeps growing each year. If you are curious to know how solar photovoltaic panels work to harness sunlight and power households, then this article is just for you.
But before we get to how solar panels work, first, let us look at the most important part of the modules: photovoltaic cells.
What are photovoltaic cells?
Solar electric cells are energy-harvesting devices that capture the energy contained in sunbeams and transform it into electricity through an activity referred to as the photovoltaic effect.
This activity takes advantage of silicon-based semiconductors in the make-up of the cells to capture energy-bearing particles called photons that are found in sun rays. Once captured, the photons release solar electrons that then travel through a circuit, creating electrical energy.
Also, photovoltaic PV cells give the most common photovoltaic modules their characteristic blue color. The image below shows what these cells would look like on a photo-voltaic module. More on how PV cells work in the following section.
How do PV cells work
If you are considering adopting solar power systems in Florida, you may not need to know the nuts and bolts of how photovoltaic cells work to produce power. Your photo-voltaic contractor should already know that and how it influences the choice of solar panels for your home.
However, if you are curious to know exactly what you will be spending thousands of your hard-earned dollars on then let us delve into the nitty-gritty.
The light we perceive from the sun carries a lot of energy contained in particles called photons.
It is the interaction of these photons with the silicon-based semiconductors in solar-powered photovoltaic cells that develops electricity. To understand how solar power cells work, first, we need to know what they are composed of.
Structure of solar panels PV cells
Two layers of semiconductors are assembled to form a cell. In one layer, the silicon is infused with phosphorus atoms creating a structure in which there are free-to-move electrons. This layer is the n-type layer. In the other layer, the p-type layer, silicon is infused with boron atoms resulting in a structure that is deficient in electrons, thus has holes in it. A region referred to as the depletion zone is formed where these two layers come together.
How direct current electricity is developed by solar cells
In the depletion zone, some free-to-move electrons from the n-type layer at the top move to fill the holes in the bottom layer, the p-type layer. An electrical field is thus created around this zone in which at the top where the depletion zone meets the n-type layer, there is a positive charge. Conversely, at the bottom of the zone, a negative charge is created.
When light strikes the depletion zone, photons in the light cause electron-hole pairs in the depletion zone to be released from the neutral atoms, and due to the electrical field created, electrons will move up into the n-type layer owing to the positive charge that attracts them there. In contrast, the holes will start to accumulate in the lower region of the cell, the p-type layer.
The concentration of electrons in the negatively charged n-region and holes in the positively charged p-region rises significantly, creating a potential difference. When you connect a load across this potential difference, electrons will migrate through the load/circuit from the n-region to fill holes in the p-region creating a one-directional flow of electrons in the circuit that we call direct current. And that concludes our simple explanation of how solar PV cells work.
What are the main types of solar cells?
As mentioned earlier, the photo-voltaic modules you see on most roofs are either blue or black. But why are there differences in the appearance of photovoltaic solar panels?
These colors are a result of differences in the silicon lattice structure of solar panels PV cells, giving rise to two main types of cells: polycrystalline and monocrystalline. Polycrystalline cells have a random silicon lattice structure, resulting in less efficient cells.
For an increased cost, polycrystalline silicon can be processed to become monocrystalline silicon which boasts a much higher electrical conductivity. But due to being more expensive, monocrystalline cells are not utilized as widely as their polycrystalline counterparts.
How do solar panels produce energy?
When sunbeams strike against the glass surface of photovoltaic solar panels, very few of the sunbeams are reflected away (about 2%) while most of the sun rays reach the solar panels PV cells.
The cells then transform the light energy to direct current electricity, which is then transmitted by copper wires to the inverter where it is altered to alternating current that powers most appliances in the home. Any extra energy not utilized within the house is then either stored in batteries or directed to the grid, in the case of net-metered setups.
If the electrical energy is not stored or directed to the grid, it is dissipated and lost. This is why sizing a system is important, hence the need for residential solar power estimates to see how much surplus energy can be stored or sold to the grid.
Do solar panels work during a power outage? If you are connected to the grid, then you will be shut off during a power outage to protect the personnel working on the powerlines from live wires from photovoltaic modules. However, there are ways to ensure you still enjoy the benefits of photovoltaic modules during a power outage.
Having hybrid solar power allows you to have a physical grid connection that you can switch off during a power outage so that you enjoy the energy from your modules and batteries.
Steps in solar energy generation and transformation
How do solar panel photovoltaic systems work residentially and commercially?
Sunbeams activate PV modules
PVs transform natural light energy into DC electricity
DC electricity from the PV goes through an inverter to be altered to AC electricity. In off-grid or hybrid setups, a charge controller takes some DC from the modules and uses it to charge the batteries, while the rest goes to the inverter.
AC power is distributed to appliances and the rest is directed to the grid. In the case of commercial setups, the electricity is primarily directed to the grid.
There has never been a better time to go solar than now. The costs of going solar have significantly gone down in the past decade, making it possible to achieve savings in the long term. If you wish to go solar, why not do it with the best in the industry?
Contact Innovate Solar today and we promise to give you a PV setup that meets your energy demand, is cost-effective, and gives you great savings. And if you are a solar contractor, join our solar distributorship and get zero-cost high-quality leads.