Solar panels essentially help us to harness energy from the sun and convert it into usable electricity. The high level explanation for this is that solar cells absorb sunlight and convert it into an electrical current, through a process known as the photovoltaic effect. The electrical current is then captured by special plates and wires and is then converted into current you can use at home.
In this article, you will learn about how solar PV generates electricity that can power our homes and businesses. We’ll start with the basics of how solar energy is produced and proceed into the specific mechanisms of PV systems.
What is a Solar PV System?
At the core of solar panels lie solar PV cells, also known as solar cells. Typically made from semiconductor materials like silicon, the solar cells are the fundamental units responsible for converting sunlight into electricity. When sunlight strikes a solar cell, photons from the sunlight are absorbed by the semiconductor material. This absorption of photons imparts energy to the semiconductor electrons, dislodging them from their atoms and generating an electric current.
The mechanism by which solar PV cells convert sunlight into electricity is referred to as the photovoltaic effect. This mainly involves the converting light (photons) into electricity (voltage). When sunlight interacts with a solar cell, it excites electrons, initiating the flow of an electric current. This electric current traverses through the solar cell and can be captured for use as electricity.
A solar PV system such as pvgeneration.ie is basically a combination of solar panels along with the hardware needed to help electricity flow through the panels and into the inverters. In most cases, multiple solar panels are put together to create a solar array, capable of generating significant amounts of electricity. The size and efficiency of these solar panels determine the total electricity output of the solar PV system.
Moreover, depending on the specific system, a solar PV system could use microinverters, string inverters, or power optimisers to convert the energy into usable electricity, but the basic setup of most PV systems is the same. More on this later.
Main Parts of a Photovoltaic System
The basic solar PV system is made up of the following components:
Solar modules: These contain the PV cells that convert light into electricity.
Solar inverter: The main purpose of an inverter is to convert DC power to AC electricity. It can also be used to perform other functions that can be beneficial to the solar system installation.
How Solar Energy Works in a PV System
Solar panels produce direct current (DC) electricity, which often has to be transformed into alternating current (AC), as most household and commercial electrical systems operate on AC. This conversion is typically done by an inverter. AC current can also be sent back to the power grid, which operates with AC current.
Solar PV systems can be linked to the electrical grid, facilitating the efficient distribution of electricity. Surplus electricity generated by the solar panels can be fed back into the grid, usually through net metering programmes. Grid-connected solar PV systems serve as a dependable source of renewable energy, while allowing the owners to enjoy energy savings and potential incentives.
In remote areas with no access to the electrical grid (or for those who prefer to stay off-grid), off-grid solar PV panels for businesses and homes can provide ample electricity to homes or businesses. These systems usually integrate batteries to store excess electricity generated during the day for utilisation during periods of diminished sunlight or at night. Off-grid solar PV systems allow for energy independence and can be a cost-effective solution for powering remote homes and businesses.
What Affects the Efficiency of a Solar PV System?
Even under ideal conditions, solar panels cannot be 100% efficient with current technology. The efficiency losses can become even more significant when the solar panels are installed on the roof of a house. Some of the main environmental factors that could negatively affect the efficiency of a solar PV system include the following:
Temperature: The efficiency of solar cells is inversely proportional to the temperature. As such, the hotter it gets outside, the less efficient the system, and the less electricity the system will generate, all other elements held constant.
Obstruction from dirt and debris: Whenever dirt and debris accumulate on the surface of the solar panels, they can block sunlight from effectively reaching the solar cells, which reduces the amount of electricity they can generate. The energy losses will depend on the amount of obstruction on the solar panels.
Shading: When surrounding buildings, trees, terrain, or other objects fully or partially block sunlight from reaching the PV system.
Inverter efficiency: Converting DC to AC electricity is about 96% and 97% efficient. When the DC input power is high, solar inverters are typically able to get higher conversion efficiency rates.
Age: According to NFC Energy, Solar panels typically produce less energy the older they get. This is usually factored into the PV modules, and most degradation rates are about 0.5% a year.
Solar PV systems present an effective way to lower your carbon footprint and save money on utility bills. An understanding how solar PV produces electricity, you’re better placed at optimising the benefits of your solar system installation and staying on top of your carbon footprint.
If you want to learn more about solar PV cells or are interested in solar panels, feel free to talk to an expert today. Be sure to also check out the energy department’s website to find out if you’re eligible for rebates and other incentives for installing solar.