Types of Solar PV Panels

You are here

Photovoltaic panels are a 3-2-1 proposition: they come in three flavors, two installation types and with one additional option. The three flavors are monocrystalline, polycrystalline and amorphous; the two installations are building-integrated or panels; the additional option is a tracking mechanism.

PV Flavors

The most efficient – and most expensive – flavor of PV panels is monocrystalline. They are made up of cells cut from a single silicon crystal (and look like a slice of one). They are smooth and you can see how thick they are. Monocrystalline PV panels must be mounted in a rigid frame for protection.

Polycrystalline cells are built out of slices cut from a block of silicon (which is made up of lots of crystals). They look "speckled" compared to the monocrystalline flavor and are slightly less efficient. They're also a bit cheaper. These panels also need a rigid frame for protection.

Amorphous cells are unlike the other two flavors. They are created by spreading non-crystalline silicon across a surface. They're the least efficient and least expensive, but they can be spread on a large variety of materials, including flexible options and odd shapes. Amorphous cells are unusual in that their power output starts off high and wears down over the first few months: any power quotes should be for their relatively stable output after this initial period.

In most cases, panels are a collection of cells measuring around 2.5 by 5 feet and produce between 170W and 200W per panel. Newer panels almost always offer better efficiency than older models, so it's worth looking for the latest release.

Bear in mind that the overall cost of a PV system is not simply a case of choosing which flavor fits your budget: their efficiency and installation style govern space requirements which can, in turn, make more expensive individual panels a cheaper choice overall. Consider all the factors before deciding.

PV Installations

Most residential solar installations use panels: those rigid, usually roof-mounted blocks of solar cells which are so familiar. However, there is another option: integrating the cells into the building itself, for example as a curtain wall exterior or skylight glazing.

For building integration, solar cells can be applied to existing structures – for example, using cells which "peel and stick" to most surfaces (though they're commonly used on the roof) – or they can form a fundamental part of the structure, such as cells which are laminated directly onto construction materials (again, commonly roofing materials such as tiles).

The main down side of integrating PV cells into a building is that they are usually less efficient. This, in turn, means that you'll need a larger surface area to generate the same amount of power as a rigid panel. They also tend to have a shorter life span than the materials on which they are stuck or laminated, which can cause maintenance hassle at a later date. Peel-and-stick cells have a life of about 10-15 years, for example, and are harder to remove and replace than doing similar maintenance on a rigid panel.

Tracking Option

Tracking panels