Solar Panel Information

What shapes, sizes and types do solar panels come in?
Solar panels (a.k.a. Photovoltaic or PV modules) vary in length and width, and are often about 2 inches thick. They are generally about 30 pounds or less, but the larger ones (5' x 3') can be cumbersome to carry on the roof. We carry a wide selection of solar panels: framed, foldable, rollable and laminates for the roof. Framed solar panels are the industry standard, most cost effective, and applicable for most home solar panels applications.
Foldable Solar Panels are lightweight (less than 5 pounds) and can fold up and fit easily in a backpack. Flexible / Rollable Solar Panels are also lightweight, but bulkier than the foldable panels. Many people use these rollable panels on boats because they are durable and can be easily stowed after use. Roofing Solar Panels (laminates) are becoming more common, but are still available on a limited basis for now. Generally these thin-film laminates are more expensive per watt and require more square footage to produce the same wattage of equally sized framed module.
What size solar panels do I need and how many?
The number of solar panels you will need depends primarily upon the amount of electricity you are trying to produce and the insolation in your area. Insolation can be thought of as the number of hours in the day that the solar panel will produce its rated output. This is not equivalent to the number of daylight hours. You'll find solar panels in a variety of wattages. Watts are the main measure of a solar panel, along with nominal voltage . For a rough idea of how many watts of solar you will need, start by dividing your electrical usage (in watt-hours per day) by the insolation in your area. Bump that number up by 30-50% (to cover system inefficiencies) and you'll have an idea of the number of watts of solar panels you will need. If that number is more than 1000 watts, you are talking about $10K or more for the solar electric system. (Could we take this opportunity to mention the importance of energy efficiency again?!) If you could still use a little help with the math, please give us a call and tell us how much electricity you are trying to produce (in kwh/month or watt-hours/ day ) and your location, and we'll help get you started.
What types of solar panels are there?
Most solar panels can be classified as monocrystalline, polycrystalline or amorphous. This is based on the silicon structure that comprises the cell. It's not quite as complicated as it sounds. Basically a 100 watt monocrystalline solar panel should have the same output as a 100 watt polycrystalline panel and a 100 watt amorphous panel. The main difference is the amount of space which the panel occupies. Because the monocrystalline structure is more efficient than amorphous in turning sunlight into electricity, the amorphous panel of the same wattage will be physically larger. By the way, when talking about efficiency of solar panels, keep in mind that solar panel efficiency is still only about 13-18% efficient in turning sunlight into electricity. Often amorphous panels are less expensive than the crystalline panels. If space is not an issue, than an amorphous panel could be a great option. Additionally, amorphous panels perform better than crystalline panels in very hot temperatures and are also slightly more tolerant of partial shading.