The sun creates an enormous amount of energy, so much in fact that the amount of energy produced by the sun on Earth in a single hour is more than enough to power the entire world for a year. Offering a virtually unlimited supply of power, solar energy is thought by many to be the answer to ending our dependence on fossil fuels, but until recently, few could afford a solar installation.
Thanks to considerable production and manufacturing advancements, government subsidies to fund extensive research, and decades of trial and error to inform today’s solar energy market, the cost of installing solar panels is now a shocking 99% lower than it was forty years ago.
Today, businesses, manufacturers, commercial laboratories, educational institutions, and many more are taking advantage of the historically low cost of solar panels. By converting to solar energy, these institutions are not only reducing their carbon footprint and unlocking energy cost savings, but investing in clean energy for decades to come.
Of the many varieties of solar panels available today, three standouts have become the most popular on the market. In this blog, you’ll learn the basics of how solar panels work, and which of the three most popular varieties you should consider for your business, institution, or laboratory facility: Monocrystalline, polycrystalline, or thin-film solar panels.
What Are Solar Panels?
Solar panels absorb and collect energy from the sun, converting it into usable electricity. Each panel (sometimes called a module) is made up of an “array” of solar cells, each of which is composed of photovoltaic materials with semiconductive properties. A single solar panel typically has between 60-96 individual solar cells, all tightly packed together and affixed to a metal frame. As the rays of the sun hit a solar panel, the photons are captured by the solar cells, which push them in a single direction. As more sun shines on the panels, the photons are pushed forward, creating an electric current that can be transferred and utilized.
Solar cells are made from layers of semiconductive and protective materials. Most commonly, today’s solar cells are made from silicon crystals.
Silicon is a semiconductor element that can absorb the sun’s rays but does not produce a current on its own. To help carry/direct solar photons to produce an electric current, small amounts of boron or phosphorus are mixed in with the silicon crystals to create a conductive lattice pattern that both traps the sun’s rays and directs them to create direct current (DC) electricity.
A built-in inverter in each solar cell converts DC electricity to alternating current (AC) electricity, which is what powers electronics, businesses, homes, etc. Because silicon has a naturally shiny finish, most solar cells also include an anti-reflective layer, allowing the silicon to absorb photons rather than reflecting them off and away.
Beneath the silicon layer, most solar cells are built on a conductive metal plate, which also helps to make affixing the solar cell to the module easier. Finally, each solar cell is covered in a protective layer of glass to prevent rain, snow, hail, dust, and debris from damaging the inner components.
Solar Cell Efficiency
If two solar panels are placed in the same place and exposed to the sun for the same duration of time, the one that produces more electricity receives a higher efficiency rating. Solar cell efficiency is simply how well the cell converts photons into electricity, with higher efficiency meaning more power. Today’s modern solar panels are comprised of solar cells with efficiency ratings of between 15% and 23%.
How well a solar cell performs depends on its composition, materials, and electrical configuration, with certain designs and types of solar cells offering more potential for efficiency than others. While efficiency is important, many lower-efficiency but less expensive solar cells can produce plenty of power for smaller businesses and facilities.
Monocrystalline Solar Panels
If you imagine a solar panel, you are probably imagining a monocrystalline solar panel with solid black solar cells laid in a grid pattern. To identify a monocrystalline solar panel, look for the slightly rounded edges of each solar cell. One of the oldest types of solar panels available, monocrystalline solar panels were the standard for years before the solar panel industry began to open to a wider market. Monocrystalline solar panels have remained a popular choice among those looking for high efficiency, but their equally high cost has made monocrystalline a slightly less popular choice in recent years.
As the name suggests, monocrystalline solar cells are created using slices/wafers of a single silicon crystal. Each slice is perfectly uniform in structure and identical to the others, creating optimal surface area to catch the sun’s rays. Once cut and formed into rounded wafers and layered with electrical components, monocrystalline solar cells are arranged on a metal base and covered with protective glass. Because each solar cell is made from an identical, solid piece of silicon crystal, monocrystalline cells are often the most efficient.
Monocrystalline solar panels appear to have solid black cells, creating a uniform aesthetic that is universally recognized as a solar panel. The backing and electrical components of a monocrystalline solar panel are typically colorful, though these may not be visible unless looking at the back of a panel directly.
Since each cell has rounded corners, the gaps between solar cells on a monocrystalline solar panel appear both as small diamonds and as lines. The metal frame of these modules are typically dark silver or black.
Monocrystalline solar panels are the most efficient type of solar panel, sometimes reaching efficiency ratings of up to 25%. Thanks to their uniform structure, monocrystalline solar cells can operate at higher temperatures than other types of panels, and won’t drop in efficiency when the heat goes up. In general, most monocrystalline solar panels have an efficiency rating of between 19% and 23%.
- Highly efficient
- Compact and ideal for smaller spaces
- Long lifespan, often up to 25-30 years with proper maintenance
- Easy to install, maintain, and replace
- Expensive. The solid crystals required to create monocrystalline solar cells are expensive and sometimes difficult to source. Additionally, the initial installation of this type of solar panel can be more expensive than other varieties.
- Partial coverage or an area of a monocrystalline panel can render an entire circuit ineffective, i.e. snow and dust must be removed regularly
- Wasteful production methods
Because monocrystalline solar cells are made from wafers of a single silicon crystal, the cost of producing these panels can be quite high. Creating silicon crystals involves a process called ‘the Czochralski process,’ which utilizes a huge amount of energy and raw materials.
As a result, monocrystalline solar panels are among the most expensive types of solar panels in terms of the initial cost.
Polycrystalline Solar Panels
While monocrystalline solar cells are created using a single silicon crystal, polycrystalline solar cells are produced using a combination of silicon crystal fragments. To identify a polycrystalline solar panel, look for the telltale blue hue of the cells.
Developed in the 80s as an alternative to monocrystalline solar panels, polycrystalline panels helped to make solar more accessible to a wider range of customers. Today, polycrystalline solar panels offer moderate efficiency for a low price, making them a popular mid-tier option.
Whereas monocrystalline solar cells are made from a single cylindrical silicon crystal, polycrystalline solar cells are made from a combination of silicon crystal fragments. Sometimes made from the leftover silicon from monocrystalline production, silicon fragments are mixed and melted together to form solid rectangular slabs which can then be sliced into wafers to be layered with other components in solar cells.
Fitted closely together in a grid pattern, polycrystalline cells don’t have rounded edges, making their appearance more uniform.
The combination of crystal fragments used to create polycrystalline solar panels creates a unique surface that, when lit by the sun, reflects a bluish hue. Polycrystalline solar panels may also have colorful backing components like monocrystalline panels, and similar black or grey metal frames.
Despite being made from the same basic materials as monocrystalline solar panels, polycrystalline solar panels are less efficient, typically maxing out at around 17% efficiency. Less effective at higher temperatures, polycrystalline solar panels are most efficient in moderately warm temperatures and are best suited for temperate climates.
- Low cost to produce, purchase, and install
- Easy to maintain
- Compact and ideal for tight or small spaces
- Less effective at higher temperatures. Extreme temperatures may reduce the lifespan of polycrystalline solar panels
- Only moderate efficiency
- Less aesthetically pleasing than black monocrystalline panels and thin-film panels
Because polycrystalline solar panels may be made from the waste/leftover silicon crystal from monocrystalline panel production, the material cost of producing poly-panels is significantly lower. Additionally, polycrystalline solar panels are easy to install and do not require specialized or extensive maintenance throughout their lifetime.
Thin-Film Solar Panels
Unlike traditional solar panels, which are made of a series of rigid, multi-layered cells, thin-film solar panels are made from super thin non-crystalline silicon cells, each just a few millimeters in thickness. Silicon cells bonded tightly to a plastic, glass, or metal substrate which can be directly adhered to a roof for a super low-profile solar solution.
Typically lower efficiency, thin-film solar panels are a popular low-cost option.
Thin-film solar cells are made from a combination of amorphous silicon, copper indium gallium selenide, and cadmium telluride fused to a flexible surface substrate – typically glass, metal, or plastic. Super-thin cells are arranged in strips along the substrate, which will have an adhesive backside to allow for easy installation and adjustments.
Despite each cell on thin-film solar panels being far skinnier than conventional cells, the overall thickness of a thin-film solar panel may be close to that of a mono or polycrystalline module. With matte black cells that are evenly placed in strips and a flexible substrate mat that can be adhered directly to a rooftop, these panels are by far the least conspicuous variety.
Because thin-film solar panels typically contain fewer layers of semi-conductive materials, these are among the least efficient varieties of solar panels available. Typically, thin-film solar panels have an efficiency rating of around 10% to 14%, though thanks to their low cost, their cost-per-watt is relatively low, making them extremely cost-efficient.
- Inexpensive to produce, purchase, install, and maintain
- Low-profile and aesthetically pleasing
- Extremely portable and easy to move or adjust
- Tolerant of high temperatures
- May require more surface area/space for installation
- Low efficiency
- Shorter life expectancy and resistance to extreme weather conditions
Silicon crystal is far more expensive than amorphous silicon, making the production of thin-film solar panels more affordable for manufacturers and customers alike. Additionally, because thin-film solar panels may be adhered directly to a roof, the cost of installation is far less, and the units can be moved/re-arranged without much effort.
Overall, thin-film solar panels are the most affordable option.
While each of these solar panel options is excellent in its own right, the variety you choose will depend entirely on the specific needs of your facility. Here are some basic specs of the common types of solar panels compared side by side.
|Type of Panel||Efficiency||Cost||Pros||Cons|
|Monocrystalline||19-25%||$$$||High efficiency, long-lasting||Expensive|
|Polycrystalline||15-17%||$$||Affordable, moderate efficiency||Low heat tolerance|
|Thin-Film||10-14%||$||Inexpensive, versatile||Low efficiency|
When selecting which type you will invest in, consider first the needs of your facility. If you have high energy needs and want to invest in the future of your energy consumption, monocrystalline solar panels may be the best choice for you. If you have more moderate needs and want to save a little money, polycrystalline panels will be the right choice. If you need something that offers flexibility and will get you the best value for the price, thin-film solar panels will give you what you need.
If your facility deals in creating, manufacturing, or testing solar panels we can help. At OnePointe Solutions, we can design custom laboratory layouts, industrial workbenches and provide lab-grade countertops that won’t affect the quality of the solar panels but better improve the flow and efficiency in your facility.
Need a Lab Design?
Give us a call at (866) 222-7494 or visit us online today!