Not all solar photovoltaic (PV) cells are made alike. Generally speaking, there are four different types – those made out of monocrystalline silicon, polycrystalline silicon, or amorphous silicon. And while there are a number of differences between these cells, they mostly differ in the extent to which they carry out three main functions –

• how well they absorb light produced by the sun;
• how they separate charge carriers;
• and how they carry electricity to an external circuit;

Put all these factors together and what you get (and what buyers are most interested in) is how efficient PV cells are at converting solar light into electricity. In other words, buyers want the most bang for their buck or the greatest amount of electricity delivered for the lowest cost. So which type of solar panel really delivers in this front?

Monocrystalline silicon takes the cake from a cost-effectiveness standpoint – these cells are reputed to be the most efficient all, nearly 1% more efficient than competing cells. But the problem is these cells are also the most expensive, so buyers face high upfront costs to purchases these types of panels.ⁱ

For this reason, many buyers opt for polycrystalline cells which are second in efficiency. They are one of the most widely used technologies of all. Polycrystalline cells deliver high efficiency but at a slightly lower upfront cost than its monocrystalline cousin. And polycrystalline works best for smaller surface areas, making it another ideal option for residential customers with smaller roofs.

But if you live in a warm climate and your roof has some shade cover, don’t overlook amorphous silicon. These cells aren’t as efficient as some others, but they operate well in areas with high temperatures and with partial shading caused by things like trees or other buildings.

Tips for Choosing a Solar Panel

Beyond the type of material that solar panels are made out of, there are a few others things you will want to consider when selecting a solar panel, including:

• Tolerance – Tolerance refers to the likelihood that a solar panel will achieve its full output. For instance, a solar panel with a negative tolerance may not be able to reach its 200 watt rating. Conversely a positive tolerance panel may be able to exceed its 200 watt potential.
• Temperature co-efficient – Solar panels can be susceptible to intense heat and not work quite as efficiently at different temperatures. The lower the temperature co-efficient is, the better a panel performs in high heat.
• PID resistance – Potential-induced degradation (PID) is a phenomenon that causes power loss under certain climatic conditions. Look for a solar panel will little or no PID.
• LID resistance – Similarly, light induced degradation (LID) is a process whereby light can actually destabilize and degrade a solar PV system over time, thereby reducing its output. A good solar panel will have little or no LID.
• Durability – No matter how cost-effective a solar PV system is, the durability is another incredibly important factor to consider. A product’s durability is typically measured by the manufacturer’s guarantee or by the contractor’s warranty. The best solar panels should have a warranty of twenty-five years.

Before you do anything, talk to a trained professional about the different options available to you. It all depends on what your budget is and what your needs are. Happy hunting for solar PV!

i^ http://www.evoenergy.co.uk/solar-pv/our-technology/pv-cell-comparison/