So you decide you want solar power. The first thing image most people have in their mind is of the line of solar panels to build their system foundation upon. Most of the people I talk to understand they need a solar panel, but not necessarily the differences in panel types. So let's dive into some basic information to get you started.

There are three basic types you should concern yourself with. Monocrystalline, Polycrystalline, and Thin-film. In most applications the better choice is going to be monocrystalline (Mono to installers). Mono panels are more expensive but their advantages are generally worth the cost you will pay. Polycrystalline (Poly) Panels are less expensive, but also less efficient. Both Mono and Poly panels are made of thin layers of silicon. The biggest difference, and the thing that makes Mono more efficient, is that Monocrystalline Panels are made of a single pure crystal of silicon. Poly panels are made of fragments that have been melted together and fused into a single wafer.

Thin film panels are lighter, have more aesthetic applications, but are the least efficient of the three. Unlike Mono and Poly panels they are made from a variety of materials. The bulk of them are predominately made of Cadmium Telluride (CdTe). In some cases they are made from Amorphous Silicon (a-Si).

If you have located a source for solar panels and are building a system yourself, there are a few quick things to look for that can help you identify what you are looking at. First is the color of the cells. Black cells generally equals mono panels. The frame, back, and edges of the cells and overall assembly can be a variety of colors so do not use that to determine what you have in front of you. They appear black due to the way light interacts with the pure silicon crystal as opposed to the fragments fused for poly panels.

Poly panels will generally be bluish in color. As with the mono panels this is due to how light interacts with the fragments of silicon crystal fused to form each cell. As with the mono panels the edges, frames, and other components are generally silver, gray, black or a variety of hues depending on the manufacturing process used to build them.

Thin film panels are exactly what the name indicates - low profile and thin. The cells in a thin film panel are over 300 times thinner than those used on mono or poly panels.

Efficiency with solar equipment is everything. Mono panel efficiency is generally over 20%, Poly panels are generally 15-17% and Thin Film panels are closer to 10%. That said, there may be applications due to roof load requirements when the lighter thin-film panels are the better fit for the design. In most cases Mono panels, and their generative power are the ideal choice if you can afford to integrate them into your system.

The science behind solar panels can be confusing if you have never been introduced to solar. In the diagram above the basic idea is that sunlight hits the solar panels and produces an electric field. The electricity generated by that electric field flows toward the edges into a wire. Those wires are connected like the branches of a tree in a specific sequence - pairs and pairs in parallel to match the electrical specifications needed to run through a charge controller (without overloading it) to charge a battery or bank (group) of batteries. Those batteries in turn are connected to an inverter which can convert that battery power (which will be direct current (DC)) into alternating current to match the electrical standard used to power most household devices.

Keep in mind that there are many times you can actually skip the inverter in a design if you want to only run DC current. Automobiles run on DC power. As such DC can power many devices that are manufactured/engineered to run on that power source. Just remember that most of the convenience items you have in a modern home that plug into your wall run on AC.

Next week I will dive into charge controllers and why they are an important part of your solar system.