What to Look For in Solar Panels

For residential applications, the two biggest restrictions for solar panels are cost and space. You also need to know how much power you want to produce so you can figure out how many panels you need and how efficient they need to be. To get the long-term benefits of solar panels, you need to keep the costs down. Your needs will change depending on whether you want to go fully off-grid or simply offset the cost of your electricity. With roof-mounted solar systems, there is a hard limit to how many panels you can fit on your roof. The optimal direction for solar panels to face is to the south. Depending on the shape of your roof and the orientation of your house you may be severely limited on panel space. By looking at how much power you need and how much space is available you can figure out how efficient your panels need to be. Then you can begin shopping around for panels that meet these requirements at the lowest price. It's important to remember that the panels themselves aren't the only cost in a system. Wiring, solar controllers and state or utility fees must also be factored in. Different types of solar panel work best for different applications. Here are some of the most common types of panels.

Monocrystalline

Monocrystalline solar panels are made using high-quality silicon wafers that are formed into a single crystal. These panels have very high efficiency rates, going as high as 22.5% in high-end commercial applications. They have a blackish hue when viewed in the sun and have rounded edges. Monocrystalline panels are the current highest quality panels available. They have a number of advantages and disadvantages going for them.

Advantages

This type of panel has very high-efficiency rates and a lifespan of 25 years or more. They can be made in either a rigid or semiflexible form. Monocrystalline panels are great if you want to produce the maximum amount of power for small areas.

Disadvantages

The old saying 'you get what you pay for' comes to mind for monocrystalline panels. They are by far the most expensive panels on the market. Each solar cell in a monocrystalline panel is formed from a single silicon crystal. This requires very precise manufacturing and high-quality materials. All types of crystalline solar panels suffer from temperature and shading effects. As a panel produces electricity it also generates waste heat. This temperature increase lowers the overall efficiency of the panel. Shading effects occur when a small portion of a panel is put under shade. Because all the silicon cells in a panel are wired together this drop in productivity severely weakens the production of the whole panel. If you have a large area available for panels another variety might work better for you.

Polycrystalline

Polycrystalline panels are made from silicon the same as monocrystalline panels. Instead of single silicon crystals, manufacturers used fragments of silicon that are formed into wafers. These panels have a blueish hue to them and are squared off rather than rounded at the edges.

Advantages

Polycrystalline panels are cheaper on average than monocrystalline solar panels. On a watt for watt basis, some polycrystalline panels are more cost-efficient than monocrystalline panels. Where space isn't at a premium a polycrystalline installation can make more sense. They are just as durable as monocrystalline panels and will also last for upwards of 25 years.

Disadvantages

These types of solar panel have lower efficiency rates to match that cheaper cost. On average a polycrystalline panel has an efficiency rate of 14-16%. If you only have a small amount of space available, polycrystalline panels probably aren't the way to go.

Other Types of Solar Panel

Traditional crystalline silicon panels make up the bulk of the solar panel market. Recently, however, new manufacturing processes and materials are beginning to make major inroads. Thin film panels are made by applying a very thin layer of solar absorption material onto a surface. This allows the use of up to 350 times less material than crystalline panels. Thin film panels have a uniform appearance and many people find them more visually pleasing than crystalline panels. Thin film panels are available in a wide range of sizes, shapes and efficiencies depending on the materials used. There are three commonly used thin film materials.

Cadmium Telluride (CdTe)

CdTe is the most common of the thin film panel materials, making up half the market. This type of panel has reasonable efficiencies, 14.5%, and new manufacturing methods are lowering the cost every year. CdTe panels are commonly used in large-scale commercial projects because of their low cost and reasonable efficiency.

Amorphous Silicon (a-Si)

a-Si is the most mature of the thin film technologies. If you ever had a solar powered calculator or watch a-Si was the material used to power it. It's been difficult to scale a-Si because of its low efficiency of around 8%. It is rarely used in residential installations.

Copper Indium Gallium Selenide (CIGS)

CIGS panels are a relatively new technology that is still developing. They have shown very high rates of efficiency in laboratory settings. The only real downside to CIGS panels currently is their high manufacturing cost.

Choose the Panels Right For You

Now you know the major types of solar panel on the market and the advantages and disadvantages of each variety. With a few simple tools you can figure out the amount of sunlight available to you and calculate the minimum efficiency you will need for your available space. If you want to increase the equity in your Midwestern home or do your part in reducing fossil fuel consumption, please contact us. We would be happy to set up a free solar analysis for your home.