What Are Solar Panels? How Do Solar Panels Work?
Solar energy costs are going down due to improvements in the efficiency and quality of the technology. So, more and more homeowners in Australia are looking at solar energy as a viable solution for their homes.
According to BP’s Statistical Review of World Energy in 2016, we have about 115 years of coal production and roughly 50 years of oil and natural gas remaining.
This alarming statistic is a shocking reminder of how little time we have to seek other options to fulfil our energy requirements.
As solar energy enters the mainstream market, many people are starting to wonder how solar panels work.
To explain this in simple terms, solar panels generate current when sunlight knocks electrons out of the atoms. This current then powers the entire house. Read on for a more in-depth analysis.
What are solar panels?
A solar panel can be simply defined as a grid of glass, silicon, and wires that can convert sunlight into electrical energy through the Photovoltaic effect.
Solar panels consist of Photovoltaic (PV) cells, which are the most essential component. The panels consist of groups of interconnected PV cells, and a group of panels makes up modules. A solar array consists of several modules.
Every cell in a panel has a layer of oppositely charged semiconductors.
Most consumer-grade solar panels have cells made up of silicon, which is cheap to use as it’s the most common element in the earth’s crust. It’s highly pure, easy to use, and a very affordable semiconductor, perfect for producing solar panels on a large scale.
The silicon must be entirely pure for it to give the best performance, as the efficiency of a panel is directly proportional to the purity of silicon in the cells of a solar panel.
Monocrystalline cells are purer and generate solar power efficiently while taking up lesser space than polycrystalline cells.
How do solar panels work?
The power generation begins as soon as the solar panels absorb photons through the Photovoltaic cells, generating direct current. Household appliances work with alternating current, so conversion from DC to AC occurs, and the alternating current is distributed to devices accordingly.
Here are a few steps that explain how solar panels work in your home.
Absorption of photons using photovoltaic cells
Consider photons to be tiny particles of light from the sun. When a photon enters an atom in the panel’s silicon cells, it displaces an electron, which creates a microscopic “gap” in the cell.
The electron with a negative charge travels towards the positively charged thin metallic plate at either end of the photovoltaic cell. This then triggers a charge which causes electrical current and voltage in the cell.
Silicon is preferred because, in silicon cells, the atoms can quickly separate as electrons cause the current flow.
The current generated by the solar panels is a direct current. The solar cells consist of a positive and negative conductor layer with crystalline silicon sandwiched in between.
The negative layer has extra electrons, which allow the electrons to take up the “gaps” in the silicon when the photons hit the silicon crystal and displace the electrons from the cells.
The positive layer has missing electrons, allowing it to receive the displaced electrons from the silicon to balance out the charge. Electrons can easily wander around in the silicon part of the photovoltaic cell, but due to the negative charge of one plate, they are pushed towards the positive plate.
One cell generally produces only about half a volt. Due to this, the cells usually have to be joined together to form modules that you can use to power a house.
For example, it can take around twelve photovoltaic cells for a mobile phone to charge, and it takes hundreds of individual photovoltaic cells to provide power to a house.
Changing direct current to alternating current
Homes work using an alternating current as most power distribution systems use it. Alternating current is cheaper to generate and has significantly fewer energy losses when compared to direct current especially travelling over longer distances.
So, a solar inverter is needed to convert the direct current into an alternating current. During this conversion, there is a slight loss of energy.
Solar systems usually have at least one inverter for the entire system. In some cases, there can be a microinverter in every panel. Either way, the primary purpose of having an inverter in the system is to convert DC power into AC power.
The converted current is available for use
After conversion, the alternating current flows to the mains and eventually powers your connected appliances for your entire house. This available electricity can be used to power televisions, devices, and the rest of the electrical systems in your home.
In some cases, if you’re using a more extensive array of panels for your solar system, there may be excess electricity. In that case, you can use batteries to store the current or sell it back to the local grid.
Store or sell the extra energy
You can store the excess electrical energy using a solar battery or sell it back to your local utility company using net metering.
Using net metering, the utility company will pay you for generating electricity. Depending on the policies of the local government and utility company, you may receive credits for the extra power you send back to the grid that can help you save on electricity bills.
Most companies don’t pay you back with cash for the electricity you supply to the grid but may offer discounts on gas or other accounts you have with them.
When using solar batteries, this can give you access to solar power through the night as well when solar energy isn’t generated. Usually, it’s better to go for solar batteries if the batteries’ initial cost and installation aren’t an issue.
How the weather affects solar production
The quantity of power produced by a solar system is affected by changing weather conditions, though not quite the way you may imagine.
The ideal circumstances for creating solar energy include a bright sunny day. Yet, as with most electronics, solar panels are much more effective in colder weather than in hot weather.
The cell may produce more power in the same period of time on partly cloudy winter days as a hot sunny summer day. The panel creates less voltage and delivers lesser power as the temperature rises.
How solar panels are made
Silicon, which is found in sand, is the fundamental component of solar cells. Sand must be processed and cleansed when it is taken from a quarry. The sand is heated to almost 2,000 degrees Celsius, which can then isolate the pure silicon crystals.
Using pure silicon in solar cells isn’t entirely viable as silicon isn’t a good conductor. A process known as doping is used to add impurities into the silicon. Mainly boron is added, making a bond with the silicon to create a positive charge.
Phosphorus is also added, which binds and creates a negative charge. The silicon crystals are then melted into small ingots, thinly sliced to make wafer-like structures that manufacturers can easily add to the solar panel sheets.
Silicon is shiny, so they treat it with a coating that helps absorb the sunlight rather than reflect it back. This helps minimise energy loss. Anti-reflective coatings are painted on and later baked into place.
Sophisticated machinery then sprays a layer of semi-liquid metals onto the panels, which allows the transfer of energy from the panels to the appliances you need to give power to.
Not only is this process used to make solar panels, but also to make circuits used in computer chips. One thing to remember is that although solar systems are a better option than fossil foil energy, the process used to manufacture solar panels isn’t entirely environmentally friendly as they still require the use of fossil fuels for making.
Some cells use a perovskite compound, which may include hybrid inorganic-organic lead rather than silicon as the active layer for light harvesting. Cells made from perovskite are comparatively more efficient and cheaper to produce compared to silicon cells.
How long do solar panels typically last?
Solar panels can last up to 25 years, with very little maintenance needed depending on the environment. There aren’t any moving parts in a solar panel, so there aren’t any parts that may wear out.
However, to keep the maximum energy production, you should clean your panels regularly and replace any panels that may have been damaged.
Typically, manufacturers forecast a degradation of about 0.8% every year. After 25 years, the solar power production should be around 80% off when you first install the panels.
Typically, manufacturers include a performance warranty that can last anywhere between 10 and 25 years.
Many newer crystalline panels have been reported to work at high efficiency for more than 40 years!
However, do consider the fact that solar batteries and inverters may not last half as long. Solar batteries can last anywhere between six and fifteen years, while inverters typically last ten to fifteen years.
Like solar panels, inverter and battery performance declines over time, and you may need to replace them 2-3 times within the life span of your solar panels.
Can solar panels work at night?
No, solar power production only occurs when the sunlight of a specific wavelength knocks the electron out of its orbit. This can’t happen at night, but this doesn’t mean that the system won’t provide you with any power when it’s dark.
Using a solar battery allows you to store the excess energy for later use. This way, you can still utilise the energy produced using solar. If your system isn’t providing enough energy for the night, you can still fulfil your power needs by taking electricity from your local grid.
Will solar power save money?
The initial cost for the installation of a solar system is high. However, you will start to notice a lower electricity bill in the first month of use. After a few years, the solar panels basically pay back for themselves. Especially because of government grants and finance.
The solar power payback period is a way to calculate how long it takes for your system to pay back for itself. This is the time it takes to recoup the cost of your initial investment.
Experts estimate that solar panels pay back for their costs anywhere between 5-8 years. After that, it’s basically free electricity unless you have to replace a component or two, but this is also rare.
Are solar panels a good choice for me?
Fossil fuels take millions of years to form. Humans only recently started to use fossil fuels as a source of energy around 200 years ago. Due to this massive gap between production and usage, we simply can not wait for more fossil fuels to be made. This is why we have to rely on renewable energy sources for fulfilling our energy needs.
As solar energy costs become lower and lower by the year, solar energy is becoming a more viable option for you to consider for your energy needs.
If you’re looking for a reliable solar solution for your needs, have a look at Instyle’s solar panels or read some of the reasons why you should consider a solar option for your energy needs.
We also have an in-depth blog section you can visit to learn more about solar energy. Or, you could always feel free to contact us with any queries.
Interested in solar? By clicking below you can use our smart solar calculator to find out just how much you could save with solar, what rebate you are eligible for, and the impact you will have on the environment.
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