In today’s highly competitive marketplace, the best residential solar panels for home use can be hard to pick out. A lot of subpar products crowd the market, while the best products sometimes mire in obscurity. If you’re looking to pick the best residential solar panel for your home, look no further.
Below, we’ll explain how a solar panel works, what makes one good or bad, and what characteristics you should base your decision on. We also discuss the different types of solar panel construction, the different manufacturers to choose from, and the tiering system the solar panel industry uses to sort solar panel manufacturers from most reliable to least. (Solar panels can even be used in a marine environment. Check out our favorite marine solar panels!)
A Brief Explainer: How Solar Panels Work
Before we can explain how to choose the best residential solar panels on the market today, we should explain a little bit about how solar, or photovoltaic, technology works. (Don’t worry, it’s not complicated.)
It all starts with the solar panel. In solar panels, two layers of silicon are sandwiched together. The top layer is “doped” with phosphorus to give it a positive electrical charge (extra electrons). The bottom layer is doped with boron, to give it a negative electrical charge (missing electrons). The top layer is exposed to sunlight which is comprised of energetic particles called “photons.” These photons knock loose electrons from the phosphorus-doped top layer of silicon and send them scurrying towards the junction between the silicon wafers. Conductive wiring gathers these electrons and sends them to batteries as electrical current, where they’re stored for later use as power.
Inverters in solar power systems convert that current from direct current (DC) in which the electrons flow in only one direction, into alternating current (AC) in which the electrons shimmy back and forth at periodic intervals.
As a final note, the above paragraphs are admittedly the “high-school” version of how solar technology operates. We’ve purposely omitted some of the more confusing detail in order to keep the article accessible to as many people as possible, even if you lack a science or engineering background. For more information, feel free to consult with your friendly, neighborhood world-wide-web.
How to Choose the Best Residential Solar Panels for Home
There is no single metric to determine the best solar panels for home use. Instead, you’ll need to consider a variety of factors, how they fit with your home environment and what the intended purpose of your solar home installation is. Solar panels can power everything from solar pool heaters to solar attic fans.
The chart below shows the characteristics we will discuss in the following paragraphs as they relate to the three different types of solar panel construction. I’ve left out some of the factors to be considered that don’t vary with the type of solar panel construction.
As you can see, while all technologies have made great strides in reliability, efficiencies and costs can vary significantly between the three different types of solar panel construction. Read on below to learn about those construction types and the factors to be considered in the purchase of a residential solar panel. (For all-in-one solar panel kits, check out this link to our favorite ready-made solar panel kits.)
Monocrystalline Cells vs. Polycrystalline cells vs. Thin Film
There are three main types of residential solar panels:
Each has its own pros and cons and is suitable for different tasks, although monocrystalline and polycrystalline cell solar panels have become increasingly functionally indistinguishable over the last couple of years. Thin film technology remains an entirely different beast, suitable for very different circumstances than the first two categories.
As the name suggests, monocrystalline panels are formed by one large continuous crystal structure. It is the oldest and most developed of all of the solar panel technologies. It used to be the most reliable and efficient solar technology on the market, but polycrystalline technologies have caught up to it in terms of its ability to convert light energy to electricity. This design is frequently found in portable solar panels.
Polycrystalline panels are a newer development in solar technology. They’re made up of multiple crystal structures created from the immersion of a silicon crystal seed placed in a vat of molten silicon. While they used to be significantly less efficient than monocrystalline panels, recent technological advances combined with less expensive manufacturing processes have accelerated their adoption in the marketplace. Dollar for dollar, they are now more efficient than monocrystalline panels.
These are exactly what they sound like. Thinner than mono- and polycrystalline panels, thin-film panels are usually only suitable for use in low-light environments or areas where space is at a premium. With significantly lower efficiencies than mono- and polycrystalline panels, thin-film technology has nonetheless made substantial advances in the market due to its low cost and adaptability. They can even sometimes be found in flexible solar panels.
Criteria To Consider
The reliability of a solar panel depends on the quality control exercised during its manufacture. Luckily, given the lack of moving parts in residential solar panels, reliability isn’t a huge issue in this space. Panels do not frequently fail after installation and manufacturers are, on the whole, good at siphoning out defective panels before they hit store shelves.
The best residential solar panels for home are more durable than others because of higher-quality construction and materials. Generally speaking, the larger, more established companies have more experience in the manufacture of complex electronic devices and are able to invest more in quality control processes. That’s not to say that smaller firms are totally unable to manufacture a quality product. You may wish to take a little closer look at the devices being manufactured by the smaller companies though.
You’ll need to pay close attention to this factor, as solar panels are almost always exposed to the elements and the weather, and frequently take a severe beating from mother nature over long periods of time. Durability will be a must-have in order to take advantage of their energy generation capabilities over the long term.
Solar panel efficiency is measured as a percentage of the solar energy that it can convert into electricity in standard test conditions. Standard test conditions consist of a temperature of 25 degrees celsius and an irradiance of 1,000 watts/square meter. That is roughly equivalent to a bright, sunny day in a temperate climate.
The range of common efficiencies generally runs from approximately 15% to 22%, meaning that in standard test conditions a solar panel measuring one square meter would convert sunlight into 150 to 220 watts of electricity.
Now, efficiency can vary greatly with a wide variety of factors, including the construction type of the solar panel (monocrystalline, polycrystalline, or thin-film), the amount of brightness (some kinds of residential solar panels are more efficient in lower-brightnesses), and incidence angle. This is why it is measured in standard test conditions. It maintains a level of uniformity that allows for the comparison of different solar panels.
This is a pretty straightforward consideration. More money equals bad. Less money equals good. Of course, it’s never actually that simple. Some solar panels may be more expensive because they come from reputable firms with high-quality manufacturing processes that result in more reliable and efficient solar panels. Other solar panels may be less expensive simply because they’re less reliable or efficient than their more expensive cousins. And do you really want to spend a little bit less for a lot less reliability? (Check out this article on whether you should buy or lease your solar panels!)
Cost per watt
Cost per watt is a good metric to consider. To determine this, simply divide the total cost of the solar panel by the number of watts produced by that panel. In that way you’ll determine how much it costs to produce each watt of power.
The following table contains data from a typical American solar panel installer and representative solar panel data from a variety of manufacturers. As you can see, the cost per watt of electricity can vary significantly.
|Brand||Cost||Watts||Efficiency||Cost per Watt|
Different kinds of solar panels have different appearances. Monocrystalline panels tend to be a solid black color, polycrystalline panels look more blueish, and thin-film panels look…well, thin. While looks probably won’t be as large of a factor in your selection of solar panel as the more functional features, they may still be worth considering. Especially when one remembers how large and visible the typical solar panel configuration can be.
Solar panel warranties depend mainly on the type of solar panel and the identity of the manufacturer. Longer warranties can stretch up to 25 years, while the industry standard is still a relatively impressive 10 years.
A large number of companies manufacture solar panels. Some are well-established multinational corporations, others are brand new boutique shops. Who you decide to go with may depend on your personal experiences, if any, with the company at hand, its international reputation for quality and reliability, and maybe even its home nation.
The most versatile solar panels are capable of generating electricity, although admittedly not at peak efficiency, in all manner of weather and cloud cover. The most frequently utilized variable measured to indicate versatility is the temperature co-efficient or the rate at which energy production decreases with every 1 degree Celsius increase in temperature past 25 degrees.
The solar panel industry has devised a tiering system to separate the wheat from the chaff. The best residential solar panels for home come from Tier 1 solar panel manufacturers who:
- Have been in the industry for five years or more
- Are publicly listed companies or are private firms with strong balance sheets
- Have production that is fully automated and vertically integrated
- Make significant investments in brand marketing
Tier 2 solar panel manufacturers fail to meet one of these criteria (often the criterion that requires a firm to have been in the industry for five years or more), while tier 3 manufacturers fail to meet several of these criteria.
The following table shows the different tier levels and efficiency spreads between 40 and 60 degrees Celsius for solar panels. We’ve used a variety of different manufacturers and selected the highest and lowest efficiency levels and temperature coefficients respectively from the solar panels they each have on offer.
|Solar Panel||Tier||Standard Testing Condition Efficiency||Temperature Coefficient||Efficiency at 40 degrees Celsius||Efficiency at 60 degrees Celsius|
|Hanwha Q CELLS||Two/Three||19.60%||-0.43||13.15%||4.55%|
|Trina Solar Energy||One||18.60%||-0.41||12.45%||4.25%|
|BenQ Solar (AUO)||Two/Three||18.30%||-0.42||12.00%||3.60%|
|Neo Solar Power||Two/Three||17%||-0.42||10.70%||2.30%|
If you were hoping for a definitive “X offers the best solar panels” type answer, I’m afraid you’re in for a disappointment. Buying the best solar panels for home entails taking a close look at the environmental conditions that will be faced by the panels you purchase, the purpose the solar panels are meant to serve, and a variety of different solar panel-specific factors. A close analysis of these things should point you in the right direction.
For example, do you live in a hot climate, require good power output, and are buying on a budget? You may be in the market for a polycrystalline panel with a very low-temperature coefficient. On the other hand, if you’re trying to add solar power in a cool environment and money is no object, then you may be in the market for a monocrystalline, tier-one product with a high-efficiency rating.
Whatever your situation might be, closely consider all of the factors discussed above. If you do, you’ll soon find yourself in a position where you’ve got your hands on the best residential solar panels for home. (Looking for more solar-themed info? Check out this article on calculating solar angles!)