Solar Panels Explained

Solar panels are a clean, emissions-free energy source that can help lower electricity costs. They’re also an excellent way to reduce your carbon footprint and decrease your reliance on fossil fuels.

Solar Panels

Solar panel installation is a big investment, but it’s worth it for many homeowners. To find the best options for your home, shop and compare quotes from vetted Solar Companies Near Me.

The large black solar panels you see on homes and businesses are made up of many smaller “solar cells” that work together to convert the sun’s rays into usable electricity. Each solar cell is a semiconductor made of silicon with two layers — a positive (p-type) and a negative (n-type). The sun’s light penetrates these layers, and the energy they absorb causes electrons to get knocked loose from their atoms, creating an electric current that flows through the cell.

The solar cells are grouped together into “panels” or “arrays,” with each panel generating its own electricity in the form of direct current (DC). A device called an inverter turns this DC power into alternating current, the kind of power that comes out of your electrical outlets. Solar panels are designed so that as much of their surface area as possible can face the sun, but if you live in an environment where the sunlight moves throughout the day, you may want to consider using panels with adjustable tilt and/or inclination.

Solar energy is the most abundant source of renewable energy in the world, with about 173,000 terawatts of sunlight striking Earth at any given time. Capturing this clean, reliable power with residential solar systems can help reduce our dependence on fossil fuels and protect the planet for future generations.

Although it’s not as efficient, solar energy still works on cloudy days. If the clouds are thick enough that they block all of the sun’s rays, electricity production can drop by 10 to 25 percent. But in areas that typically experience cloudy, rainy or cold weather, such as New York City, San Francisco, Milwaukee and Boston, solar panels can still produce a significant amount of power.

The main advantage of solar energy is that it provides a renewable, clean and inexpensive alternative to burning fossil fuels to generate electricity. Homeowners who install solar panels through a lease or power purchasing agreement should begin seeing savings on their energy bills almost immediately. And if they’re producing more power than they need, they can sell it back to their electric utility through net metering. Homeowners will typically achieve a return on their investment in seven to 12 years, depending on the type of system they choose and where they live.


Monocrystalline solar panels use a single silicon crystal that’s grown in a lab into a cylinder called an ingot, then sliced into thin discs known as wafers. The octagonal shape of the wafers reduces wasted space and allows more solar cells to fit into each panel, increasing their overall efficiency. This also gives electrons more room to move through the wafer, which increases their ability to generate electricity.

The wafers are then infused with nitrogen and phosphorus to create a powerful p-n junction, which is the heart of a solar panel. Since silicon is naturally positive, the p-n junction is needed to convert sunlight into electricity. Without the p-n junction, a solar cell will only convert about 13% of the sun’s light energy into electricity.

While a p-n junction is essential for solar energy conversion, it’s also important that the silicon wafers be roughened and etched, which improves their ability to reflect sunlight rather than absorb it. This reflects light and improves the performance of a solar panel, particularly in low-light conditions.

Because they operate at higher efficiency rates than polycrystalline or thin-film solar panels, monocrystalline solar panels produce more energy per square foot and can help you save money over the lifetime of your system. Their durability, reliability and high power output ratings make them an excellent choice for commercial and residential installations, especially in areas where space is limited.

You can recognize monocrystalline solar panels by their uniform dark look and rounded edges with small gaps between them. They are the most expensive type of solar panels, but they have the longest lifespans (currently set at around half a century).

As long as they’re exposed to direct sunlight, your monocrystalline solar panels will continue to work. However, to maximize their performance, keep them free of dirt, debris and shade, and make sure the inverter is working properly. You should also clean them from time to time with a water hose to prevent any buildup from occurring. Solar panel cleaning helps to ensure that your system is producing as much power as possible, which reduces your electricity bills and limits the amount of fossil fuels that need to be burned in local energy plants.


Polycrystalline solar panels are usually cheaper to install, but they don’t offer the same efficiency rate as monocrystalline options. This means they produce fewer watts per square foot and require more surface area to generate the same amount of electricity. Still, this option is a good choice for homes in warmer climates and areas with limited roof space since they can maximize their electricity production over a smaller area.

These solar panels use multiple silicon crystal fragments melted together. Once solid, they’re cut into thin discs called silicon wafers and then sliced into octagonal shapes to reduce wasted space and provide more surface area for electrons to move around. Unlike monocrystalline, this design doesn’t create waste since the leftover materials can be reused. However, the extra steps and cost involved in this process can make them more expensive to produce than monocrystalline solar cells.

The difference in energy conversion between mono and polycrystalline solar panels isn’t huge, but there is a significant difference between their appearances. Mono solar panels have a sleek black look that blends well with most roofs and tend to be preferred by many homeowners. Polycrystalline solar panels, on the other hand, have a blue color and stand out from the rest of your roof.

Both types of solar panels offer a long lifespan and excellent energy output, but the type that’s right for you depends on your specific circumstances. Consider factors like the available roof space, warranties, energy needs and budget, the local climate, and how much electricity you want to produce.

You might also want to explore alternative solar options such as thin-film solar cells, bifacial solar panels, copper indium gallium selenide (CIGS) and dye-sensitized solar cells. All of these different technologies utilize different photovoltaic substances to convert sunlight into electricity, but each offers its own unique set of benefits and applications.


Unlike mono or polycrystalline solar panels, thin-film solar cells have a semiconductor layer that covers the whole panel and is not embedded in each individual cell. This allows for much thinner solar panels which means less materials, lower manufacturing costs and a smaller ecological footprint than other photovoltaic technologies. The semiconductor layer is typically made out of a combination of different materials that are combined together to produce the desired solar panel performance. This technology also lends itself to a wide variety of unique and interesting PV panel designs.

Thin-film solar panels are typically more affordable than crystalline silicon (c-Si) solar panels and can often pay for themselves in about 10 years. However, they are less reliable and have lower efficiency rates compared to c-Si panels. For this reason, they are better suited to applications where the sun is more abundant than in most residential settings.

One of the earliest thin-film solar panel types is amorphous silicon, which uses a chemical vapor deposition process to place a layer of silicon over a glass, plastic or metal base. These non-toxic solar panels have a very low efficiency rate of about 6% to 8% but can be very durable and cost-effective for long-term use, especially in commercial applications.

Cadmium telluride (CdTe) and copper indium gallium selenide (CIGS) solar panels are the most common thin-film PV types. These layered panels are not as efficient as c-Si panels, but they are less expensive and offer a variety of other benefits. CIGS and CdTe panels are more effective at absorbing low-light sunlight than other PV panels and are much less dependent on the intensity of the sun or its direction.

Another important benefit of these types of thin-film solar panels is that they work on cloudy days. This is because the layers in these solar cells are able to capture and convert a wider range of light frequencies. For instance, CIGS and CdTe solar panels can absorb sunlight from 250nm-1750nm, which is greater than the spectrum of most other PV cells.