Technological advancements have provided us with clean and renewable ways to reduce our dependence on fossils fuel. Solar power is one of them along with other familiar types like hydropower, wind, and geothermal sources.
Solar panels are at the heart of these developments, making practical applications for standalone setups including private homes. But how do they work, and are they as feasible as you might think?
History of Solar Panels
This concept isn’t new. Alexandre-Edmond Becquerel first demonstrated its potential in 1839. Albert Einstein followed up on this early work by describing the photoelectric effect, earning him the Nobel Prize in 1921.
The start of widespread use began when Bell Laboratories created the first PV cell in 1954. Like many significant scientific breakthroughs, the space industry took over the reins before other manufacturers with varying applications coming on the scene.
The technology struggled at first with a couple of stumbling blocks including:
Solar power had a slow start until 2012 when it started to capture a more significant share of the clean energy net generation. It rose to its highest ever level to date in 2018 with 66.6 billion kilowatt hours. And there is no end in sight with a staggering 49.9 percent annual growth in the United States between 2013 and 2018.
Let’s begin with by going to the source of this form of renewable energy.
What Is Solar Energy?
Solar energy comes from the sun in the form of heat and light energy. If you notice its warmth on your skin when you’re outside, you are experiencing its thermal effects firsthand.
Solar panels are the equivalent with the direct energy perspective. Then, how is solar energy converted into electricity?
The answer lies with the construction and materials of the device.
Each panel consists of a number of solar or photovoltaic (PV) cells, strung together to produce a given amount of energy. They contain semiconductor materials like silicon with positively and negatively charged sides on their covering.
When sunlight strikes them, it excites the electrons, creating a flow of electricity. A conductor attached to both charged sides of the device can direct this current and use it to power something else like a lamp in your living room.
So, solar energy comes from the sun which a solar panel uses to convert it to electrical power via PV cells.
Anatomy of a PV Cell
The design of a solar panel consists of a number of cells which can range in size from your thumbprint to the width of your hand, depending on the application.
The output from a single cell isn’t a lot, typically about 1 or 2 watts. Strings of connected pieces increase the amount of energy to form larger units called panels or modules. Several of these parts in a set is an array.
It’s not unlike putting together Legos to match the amount of DC power converted to AC that you need for a site.
They consist of a positive (P) and a negative (N) side with a semiconductor that handles the action. Smaller ones have a single junction or gap between the two layers where the current flows from P to N.
These two silicon pieces may have added impurities that overcome the restrictions of the chemical structure in a process known as doping. The result is optimal flow and better conducting power. An antireflective coating contains the energy generation to the cell along with glass to protect the contents.
As you might guess, the single channel limited its effectiveness because energy could flow only if it were higher than the gap. The first solar cells only had an efficiency rate of 6 percent.
Advanced technology has ushered in a new era of possibilities with multijunction (MJ) solar cells. They consist of many single-junction barriers that tap into a broader spectrum of the sun’s light energy. The efficiency rate has leaped to 46 percent in recent years, putting it on track for even higher figures and far-reaching usage.
Let’s move onto the current state of the industry and kinds of solar panels.
Materials and Types of Solar Cells
Researchers experimented with several materials during the development of solar cells from its beginnings using silver compounds. The result is more affordable products with improved components.
Several elements come into play with this technology that is often a balancing act between:
The value is typically expressed as a cost per watt for comparison purposes. The performance depends on the materials and design of the PV cells. It is often associated with the cost with the manufacturing expenses, another critical part of the equation.
The time that the PV panels last is another vital factor that can affect your return on investment. Finally, there is the amount of room you need to set up a solar panel system. This spec is typically a function of the energy efficiency.
Unlike wind power, this power source has a larger footprint, especially if ground-mounted. Rooftop or wall installations can optimize the use of space, making it less of an issue. Bear in mind that what you give up in efficiency often increases the size of your installation with more panels and higher costs.
You’ll see products comprised of one or more materials using other things such as plastic or glass to reduce your initial investment. The construction affects all aspects of going solar along with your bottom line down the road.
Let’s consider how each of the kinds of solar cells work with these traits in mind.
Silicon offers some significant advantages, including:
It has the most widespread use in the industry and the type you’ll most likely see in a broad range of applications. Silicon is the base. However, there are several different designs with various pros and cons.
Monocrystalline Solar Panels
Monocrystalline solar panels cost more but offer a better value because of their longer lifespan and higher efficiency of up to 35 years and 24 percent, respectively.
Silicon has a crystal structure which affects the movement of electrons within the PV cells. These panels have extremely thin pieces, consisting of only one crystal, hence, the name. Their compact design makes it easier for the charged particles to flow which, in turn, bolsters their output.
They also require less space than other products for residential use. You can recognize these solar panels with their black color surfaces.
Polycrystalline Solar Panels
Polycrystalline solar panels stand out as a viable alternative with costs from 10 to 50 percent less than monocrystalline options. However, they may last only up to 27 years with about a 20 percent or less efficiency rate.
The construction is less pure too because the manufacturers melt silicon into larger pieces before cutting them into wafers. That means they have a higher percentage of crystals, which affects the flow of the electrical current. However, it also accounts for the cheaper price tag.
Because of this process, the solar cells appear blue instead of black. It’s a minor point, but it may play a role in the aesthetics of your home.
Thin-Film Solar Panels
Thin-film solar panels along with monocrystalline and polycrystalline products are the ones you’ll most like find for residential use.
They offer several advantages to the prospective buyer. They are less expensive. The reason is because of their construction. They consist of multiple layers bound to other non-PV materials like metal. That keeps the costs in line but also decreases their efficiency and lifespan.
That means you’ll need a larger installation to provide comparable energy output like the silicon ones. Other factors affect it too, such as the type of material used in the PV cells.
Amorphous PV Panels
Amorphous PV panels differ from the previous products in that they consist of a sheet instead of a patchwork of silicon pieces. That feature increases their flexibility and reduces its cost because the manufacturing process requires less raw material.
However, there is a tradeoff with efficiencies at about half that of monocrystalline and polycrystalline solar panels.
Cadmium Telluride Solar Panels
Cadmium telluride solar panels use a similar technology as amorphous ones but with a different base. Using these compounds give them an edge when it comes to capturing the photons of sunlight. They are also cheaper with minor compromises in efficiency.
The downside is the use of cadmium. While it is naturally occurring, this chemical is also toxic with known harmful effects. That makes getting rid of spent panels an environmental issue.
Copper Gallium Indium Diselenide Solar Panels
Copper gallium indium diselenide solar panels combine some features of the amorphous and cadmium telluride PV panels with better efficiency and the flexibility that makes them more versatile. They use similar technology with multiple thin layers. You’ll typically see them with newer and next-generation products.
On the downside, the toxicity of cadmium is still problematic, along with its higher cost. More research is necessary to streamline the manufacturing process to make it more affordable.
Organic PV Panels
Organic PV panels are the new kid on the block bringing customization options to the table for optimizing their performance based on traits like light sensitivity and other specifications. They also consist of layers using organic instead of inorganic compounds between the electrodes.
The potential exists for creating panels for specific function along with the option to change their appearance from the typical black or blue colors.
Unfortunately, the same problems of cost and low efficiency exist with this type too.
Residential Installation of Solar Panels
Setting up a solar power system involves some preliminary research of the elements that can affect the operation of PV panels. Things to consider include:
As you can probably see, solar is more involved than simply getting a furnace installed and connecting service. Some of these things can also put it in the dealbreaker category, so they’re worth reviewing before you invest.
Where you live has a direct impact on what you can expect to spend on the total package. It can affect details like the cost of your materials, labor expenses, and any type of fees for permits or any other miscellaneous charges.
There’s also another consideration. The total cost of going solar isn’t cheap despite the myriad of incentives, rebates, and tax breaks you can receive. The crucial issue boils down to when you can recoup your ROI.
If what you pay for electricity is reasonable, you may find that it’ll take much longer to make your money back. Therefore, you need to put all the local influences on the table too.
We’ll discuss other aspects of your location later in this piece.
The actual physical site of your house has a vital role in your solar power installation. After all, the single best way you can ensure that you’ll get the most for your money is to have the optimal setup.
That means nothing in the way of sunlight making it to your solar panels. That includes:
Your PV panels will perform the best if your house has a southern exposure with a roof angle between 15 and 40 degrees. Anything more or less limits the amount of direct sunlight reaching them, which, in turn, affects their output.
Many homeowners opt to install solar panels on their roofs or walls of the building to avoid encroaching on precious backyard space. But, your house has to have a sound structure to support their weight and last for a decent period.
An inspection of your home by a trained professional will answer this question quickly.
It’s worth noting that you’ll need to make the necessary repairs if there are issues which add to the cost of the installation—and your ROI.
Kind of Mount
As we discussed earlier, building-mounted setups are an excellent option if space is at a premium. However, there are other factors you need to consider that these types of installation directly impact.
You have three choices that include:
The first option is the least expensive but also the most inefficient. As the term implies, the solar panels don’t move and stay in one position all day long.
If you live in an area that receives an average of over four hours of direct sunlight year-round, it’s not as much of a problem than if you live someplace with wide swings in a seasonal variation like the Upper Midwest.
The second choice gives you the ability to capture more sunlight, which improves electricity output. It also offers you some latitude to account for changes in the sun’s angle throughout the year and to lay the units flat if you use them only during the summer.
They cost significantly more than fixed ones, but you need to balance it with your overall energy savings. You may find that the initial investment is worth it in the long run.
The final mount is the ideal way to get the most of your solar power system. It maximizes the amount of sunlight that the panels receive to get the highest number of kilowatts of electricity.
Remember, this installation differs from other sources because of the cash outlay you must make before you even switch it on for the first time.
That said, a tracking mount will run you 10 times or more the cost of an adjustable one. However, you have to balance that figure with what you’ll receive in return, namely, upward of 40 percent or more in energy production.
The romantic notion of a living off the grid with only solar energy to power your home is perhaps more fanciful than real. Standalone installations are the exception instead of the norm.
The fact remains that there are days when it rains. A wildfire far away can release smoke into the air and affect your solar panels’ performance for lengthy stretches. Often, staying connected to the grid isn’t a luxury but a necessity.
The primary purpose of considering it is to ensure that you always have electricity. If something interferes with your setup, you still have a reliable source of power as a backup. All of that aside, it still makes sense in case your system fails or needs maintenance, which takes it offline.
However, staying with the fold has a price.
You can expect to pay at least the cost of the basic installation for the privilege of staying on the grid. You’ll definitely need to get a professional contractor involved. And you’ll likely need extra components to your system such as meters.
It also carries other burdens related to compliance with local regulations which can up your costs. When you join the system, you play by its rules.
How Many Solar Panels Do I Need to Power My House?
Okay, so you’ve done your homework. You know what you need to do to go solar. The next question is to figure out what you’re going to need to make a budget and determine your ROI.
The first thing you have to do is figure out how much electricity your household uses to guide the purchase process.
That means finding out what you spend a year on your utilities and how it translates into kilowatts of power. Remember the cost per kilowatt we discussed earlier when comparing the types of solar panels? Here’s how you can put that information into practice.
Ideally, you’ll have data from more than one year but definitely for all months. That’s an essential part of the equation when it comes to deciding if you want year-round electricity from solar or only during the summer months. And depending on where you live, the difference is likely significant.
It’ll help you decide how much of a role you want solar energy to play in serving your power needs.
Determine how much you use each month to give you a baseline. And it all relates back to how solar panels work.
There are several factors to keep in mind that can influence these numbers. They include:
The trick is that you have to remember the lifespan of your solar power system in mind.
You’re talking 15 years with the least expensive type and upward of 30 or more with monocrystalline solar panels. The time you take with figuring it all out will save your money at the end of the day.
So, when thinking about how things might change in your home, consider changes such as appliance upgrades or additions—or new additions of the human kind.
Fortunately, it’s an easy task with manufacturers providing energy usage to help with your research. And unlike fossil fuel costs, solar power is consistent and won’t vary year-to-year, barring anything unforeseen.
Other things to keep on your radar are remodeling projects or other significant changes to your home that can impact energy use.
We suggest adding a cushion of at least 10 percent to your current monthly usage to account for things happening down the road. Then, drill down to what you need per day.
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Finding Your Ideal Setup
Now, it’s time to break out the calculator and get to some real numbers about what you need to shoot for in a system. You will also need to know the average direct sunlight your area receives in addition to the data from your electric bill.
The average system is 5 kilowatts. But as we’ve pointed out, there’s a lot of wiggle room for that figure as it applies to your household.
Let’s say you find out that you use 750 kilowatts a month. You live in the windy city of Chicago, IL which averages 4.4 hours of sunlight per day.
You can determine your ideal setup with this equation:
That number tells you that you’ll likely have to spend about $20,000 to get hooked up with for year-round service, depending on the extras you choose and have to pay based on other external factors.
Also, calculate where your ROI comes onboard. If you pay $1,500 a year for electricity, then you’re talking about 25 years to cover your bills and make back your cash.
Of course, you have room to maneuver with the type of solar panels, energy efficiency, production, and kinds of incentives you can receive for pulling the trigger.
That’s why we’ve emphasized looking at the entire picture to gauge its practicality for you. There are some other things to keep in the forefront, too including the pros and cons of making the move that goes beyond the dollar sign.
How Is Solar Power Used?
Let’s consider some uses for solar energy that make use of its capacity and advantages.
You’ve likely seen numerous applications of PV technology to power things like weather stations, speed detectors, or even electronic messaging signs. It is the type you find with homes and other structures that rely on this energy source.
Power plants, on the other hand, use a different variation on this theme called concentrating solar power (CSP). They have multiple lens or mirrors to focus the energy on a particular area. It’s not unlike using a magnifying glass to start a fire.
However, it’s essential to understand that all power sources have advantages and disadvantages. Solar energy is no exception.
When considering solar panel information, it’s a worthwhile endeavor to talk about both sides.
The Positive Side of PV Panels
There are several compelling benefits for solar power. It is the most abundant form of energy on the planet. It also has an unassailable quality about it that ensures its continued availability. After all, energy generation becomes a moot point if the proverbial well runs dry.
Also, it is also limitless for all practical purposes, unlike fossil fuels like natural gas or coal which have finite resources. These reasons are enough to push innovation and adoption of this energy source. But there are additional arguments that push the move in this direction.
Solar energy doesn’t produce greenhouse emissions after installation. That caveat is a valid point as we’ll discuss later. And the running costs are manageable for a standalone setup. An individual could live off the grid in some cases though most systems remain connected.
The discussion of solar power in its current state is intertwined with the cost.
The Limitations of Solar Panels
The downsides of solar energy are equally as undeniable. They fall into four primary categories including:
Each one speaks to the function of PV panels and have a direct effect on the feasibility of solar energy as a power source.
Solar Energy Potential
A popular talking point you’ll hear about solar power is that the sun shines everywhere. Therefore, it can replace fossil fuels without a problem.
Unfortunately, that’s not entirely true.
The efficacy of using PV panels depends on the amount and intensity of sunlight. The Southwest has enormous potential because of its geographical location. As far as the East Coast or Midwest are concerned, not so much—at least not all year long.
That means you’ll likely need a backup source of electricity, depending on your setup and location.
Other factors can interfere with the output of a PV panel based on the amount of light it receives such as:
Thus, proper placement of your solar panels is a vital consideration to control for the things you can account for and remedy.
When solar power first came on the scene, the expensive installation costs put it out of the reach of most people. Prices have come down but still hover upward of $20,000 or more, depending on the setup and type of solar panel.
Your return on investment also rests with the average amount you pay for electricity and your area’s climate. And needless to say, it’s an option for homeowners or property owners who’ll like still have the land to recoup their money.
Efficiency, as discussed earlier, is a limiting factor with solar energy. A tracking system can improve the performance of PV panels by capturing more direct sunlight. Technological advances can boost this figure, but it’s not a perfect system currently.
It’s essential to consider the entire picture when looking at the environmental costs of energy. Climate change is a negative consequence of fossil fuel use.
With solar power, the costs lie with the manufacture of the components.
Ironically, they require fossil fuels to produce. The methods for extracting the raw materials are extremely destructive with the potential to harm humans with toxic waste. There are also political considerations with China having over 50 percent of the total market share.
Solar energy has incredible potential to influence the globe in an energy-efficient way that can ensure the planet’s health and viability for generations to come.
The technology of solar cells has stood the test of time with continued refinements that have boosted its viability and usefulness. From its early start with Alexandre-Edmond Becquerel to the sophisticated advances that have put in on the world’s stage as a clean, renewable energy, solar power has secured its place in the future
However, the nascent nature of this technology requires scrutiny of its practicality and feasibility of its use for your home. The answer, after all, isn’t always clearcut.
By looking at the raw data with an honest assessment of your changing lifestyle, you can determine if it’s the right option for you and your family. The truth rests with the test of time. The limitless nature of sunlight puts solar power in focus.