How do solar panels work? A quick explanation
They’re green. They’re affordable. And in Arizona, it would be a great shame not to use them.
Solar energy is the future of renewable energy. It not only allows us to power our homes without contributing to the climate crisis, but it provides options to those living off the grid. It may just be one of the most important components of our energy plan if we want to save the environment.
The question is, how do solar panels work? It may seem like magic, being able to convert the sun into energy that powers our homes and businesses. But believe it or not, the technology goes all the way back to 1839.
In this guide, we’re going to discuss how solar energy works. Then, you’ll be ready to consider making the switch to solar services.
Understanding Electromagnetic Radiation
First, it’s important to understand how we can harness the power of the sun in the first place. The sun emits what we call solar radiation in the form of photons. These photons are a type of electromagnetic wave.
Some might be surprised to know that sunlight, radio waves, X-rays, and even Bluetooth are all forms of electromagnetic radiation. The only difference is they have different waveforms and frequencies, leading to their unique characteristics.
Visible light, like sunlight, makes up a very small portion of the electromagnetic spectrum. The rest is simply invisible to us.
But, everything on the electromagnetic spectrum contains energy. There’s a reason we can use microwaves to cook our food, for example. Being able to use that electromagnetic radiation is the key to making a solar panel work.
Sunlight: Why This Is the Ideal Renewable Energy
There are other kinds of renewable energy. For example, geothermal, pumped hydro, and wave energy. But few renewable energies are as versatile or unfussy as solar energy. All of the above and more require specific locations and can only be used in specific ways.
Since most places in the world get a fair amount of sun, they’re more often a good investment than not. The sun will keep burning for the next 5 billion years, meaning this energy isn’t going to run out anytime soon.
Not only is solar energy abundant. It could possibly power the entire world. The sunlight that hits the entire Earth for just an hour and a half could theoretically fulfill global energy needs for a full year.
There are some minor limitations to solar, which we’ll discuss later in this article. No energy source is without its downsides. However, the downsides to solar are too few to be a real deal breaker for most people.
How Do Solar Panels Work?
A solar panel contains hundreds of small photovoltaic cells. Take a look at the etymology, and you get some more insight into what a photovoltaic cell is doing:
Photo: from Greek “phos” meaning light
Volt: the unit of measurement for electromotive force, i.e. electricity
So, a photovoltaic cell is literally converting light waves into electricity. The average cell is small and may produce as little as 1 watt of power.
These cells are incredibly delicate and incredibly small. Modern cells can be measured in nanometers, one of the smallest units of measurement there are. To protect them from the elements, a solar company will sandwich these delicate components between layers of protective, durable material.
To be energy efficient and make a lot of energy, manufacturers pack panels with hundreds upon hundreds of cells. The end result? A single panel can produce several hundred watts per hour.
Of course, it’s a lot more complicated than that. A solar panel can be made out of an indeterminate number of solar modules. One solar panel differs drastically from the next.
Plus, manufacturers use different processes to make their cells. This is why price varies so much, and why you’ll need to do your research before you commit to a solar system.
How Does the Conversion from Sunlight to Energy Happen?
The main component of the photovoltaic cell is a semiconductor. A semiconductor is something between a metal and an insulator. That is, it has some conductivity properties, but not as much as a metal like copper or gold.
The most common type of semiconductor is silicon. Silicon is an abundant resource and makes an excellent semiconductor.
Semiconductors are a huge part of this world. Case in point, the device you’re using to read this article relies on them to function.
The semiconductor on a solar panel also conveys electricity, but not in the same way as a computer. It traps the photons from sunlight, which in turn knocks electrons off some of the chemical layers in the photovoltaic cell.
Ever seen those grid lines of a solar panel? Those are the conductors that capture the electrons generated by this process. They deliver this new electricity to an inverter, allowing you to use your solar energy for everyday electric purposes.
Photovoltaic Conversion Efficiency
Of course, a solar panel cannot be at 100% efficiency at all times! For starters, it might be nighttime, meaning the cells aren’t capturing any light. Or, it might be a rainy day when the sun isn’t out.
However, other factors influence how much energy a solar panel can create. For example, the angle of the sun. A lower sunlight angle is responsible for our seasons, and as such, can provide more light to solar panels.
There are other factors to consider as well. Dirt on the panels, how much heat they generate from the process, and how much light their cells can actually capture.
As a result, peak solar efficiency hovers around 20%. That may sound like a small number, but don’t be discouraged. Even with this seemingly low efficiency, the market for solar panels is one that’s only on the up and up.
Scientists are hard at work trying to discover how we can improve this efficiency. It’s a question that has proven challenging even for industry experts, so the verdict is still out. New, promising technologies such as backsheets and bifacial panels may provide future solutions.
But even if solar panels had an efficiency of 1%, they’re an excellent renewable solution, especially if you live in a sunny area.
Residents of Arizona get almost year-round sunlight. Air conditioning tends to be a heavy burden on the average person’s energy bill, making solar a great way to stay cool for cheap in the summer months.
The Solar Intermittency Problem
Critics of solar energy will often cite the solar intermittency problem. Simply put, this means that solar panels are not available 24/7, and may not be available when we need them most.
A solar panel only generates electricity during the day. At night, it cannot generate electricity. This is intermittent energy, so in the evening to night hours, we lose it.
That said, solar power often generates more electricity than the average user actually needs. In many cases, you may be able to sell your surplus power back to the grid, further reducing your electric bill.
This means that even if there is an intermittency problem, the average solar system owner won’t notice it.
Unfortunately, electrical usage is not even across the board. This is known as the duck curve.
The Duck Curve: How Energy Needs Vary Throughout the Day
Take a look at the duck curve, and you’ll see energy usage on the y-axis and time of day on the x-axis. In the early hours from 12 am onward, there’s a steady energy usage. This usage spikes in the morning when everyone goes to work, then drops sharply.
For much of the day, there’s a lull in electrical needs since most people are at work. They’re using communal facilities and generating less individual electricity per person, leading to less overall usage.
Then all those people get home, and we observe the largest energy surge of the entire day. To complicate matters, the highest spike occurs when the sun has already set.
That means that for most of the day, a solar panel is generating more energy than its users need. But when users do need it most, the solar panels cannot provide it. While selling energy back to the grid works for the individual user, it could be problematic for an entire society that needs consistent energy.
Therefore, if we’re going to save the environment, we’ll need to do something different. And that something is batteries.
How Batteries Solve the Intermittency Problem
You can find lithium-ion batteries in everything from your phone to a Tesla vehicle. They are the most efficient and cheapest battery solution in most cases. To make matters even better, their cost has gone down by 97% and continues to drop.
What many tech giants are working on are battery storage solutions. Since many renewable energies don’t generate electricity all the time, we need a way to store surplus electricity for later. The current solution is to build big farms where we can store this electricity during times of surplus, and draw it during times of need.
Remember the relatively low electrical usage early in the morning and at midday? While the solar panels are generating a lot of excess electricity, we can then store it in these battery farms. These battery farms can then dole it out when we need it at night.
Lithium-ion batteries present their own challenges, however. For starters, they have a relatively short life. Their efficiency degrades after every charge cycle. Within 10 years, they’ve lost most or all of their charge capacity, meaning they need replacement.
Unfortunately, this provides additional challenges for a solar system. The lithium-ion batteries would be constantly taking in electricity, then discharging it shortly after.
Plus, lithium-ion–while it has dropped drastically in price–adds up when you have a full bank of cells. It requires hundreds of cells. When you need to replace them every ten years, that adds up over time.
However, these downsides are not stopping all the major companies from turning to lithium-ion backup facilities. And like them, you can take advantage of the same thing!
At-Home Energy Storage
Would you rather keep that excess electricity, and use it yourself? Then you’re in luck. Energy storage solutions are becoming more and more popular with every passing year.
All you need to do is purchase a bank of batteries for your home. You install these batteries by hooking them up to your solar panels, and then your grid. And then you wait!
These batteries provide an affordable solution to the notorious duck curve. Rather than sell electricity back that you’ll have to purchase later that evening, you keep the electricity for yourself.
Advantages of At-Home Energy Storage
For starters, if you don’t need much electricity, then you’re guaranteed to have more than you need left over. You may have a small household that doesn’t have high energy costs in the evening. In this case, you may never need to purchase energy from the grid.
Further, this allows you to be self-sufficient. Power outages aren’t fun, and they could prove to be a huge problem if you work at home and rely on consistent power. A battery storage solution (assuming you live in an area with consistent sunlight) means you never have to worry about outages.
Finally, this sort of system is easy to set up. It’s a simple matter of hooking up the battery banks to your solar panels, and then letting them offload their surplus electricity. It’s hands-off and gives you peace of mind.
Get Solar Services Today
How do solar panels work? Now you know. Solar panels are the best way to save the environment, and they’re guaranteed to provide renewable energy for a long time to come.
Even if you don’t have consistent sunlight, you can avail yourself of solar energy. You can sell back your excess electricity to the grid, or you can store it in batteries for later. Whatever the case, there are easy, affordable solutions for everyone.
And if you live in a sunny state like Arizona, you’d benefit most from this impressive technology.
Check out our website for more on everything Arizona.