Altenergy

More Top Quality Solar Panels

posted Sunday, 9 December 2007

Altenergyweb, LLC  Email inquiries to: Tom@Altenergyweb.com

Silicon Photovoltaic Solar Panels

 

Silicon Solar Panels

A (Short) Primer
Silicon photovoltaic cells are fragile pieces of crystal silicon glass about the thickness of a piece of paper. Each cell puts out only about a half a volt in sunlight. This is called the open-circuit voltage, and it drops when an electrical load is attached. To make a higher voltage that is more useable, individual cells are connected together in strings to make solar panels, also called solar modules. Thin metal interconnecting ribbons are woven over and under the individual cells in a string and soldered, thereby connecting the positive underside to the negative top surface, and so on. With each additional cell connected in series, the total open circuit voltage increases by half a volt. Solar modules can be made to be any voltage, but most commercial  modules are from about 12 volts to 48 volts.

Modules are usually made by encapsulating the array of silicon cells between laminations of transparent plastic, resistant to degradation due to ultraviolet light. This seals against moisture and adds strength to the fragile cells. A covering of high transmission glass  adds further rigidity and protection. A frame of extruded aluminum or other strong weatherproof material is added. The ribbon interconnecting material is brought out to a junction box that is mounted on the back side of the panel. This weatherproof  box contains diodes that prevent damaging current reversals that can occur when panels are mismatched or shaded unevenly. The junction box is where you bring your wires to send the solar power to other parts of your alternative energy system. Some panels offer "quick connect" terminals with mating cables that ease the connection of multiple panels. Other panels have screw type terminals inside the box, and the installer provides the interconnection cable.

Note About Efficiency
The output of a solar module depends on the amount of sunlight striking the surface, the size of the individual cells, the number of cells connected together, and the cell efficiency. Larger cells produce the same voltage as smaller cells, but larger cells produce more current. Efficiency can affect both voltage and current. A highly efficient cell, 17%, for instance, is not inherently superior to a cell with a lower efficiency of say, 14%. Efficiency gauges the area of collector surface that will be needed to produce the same electrical output. In other words, efficient cells make smaller panels that produce the same wattage as larger panels made with less efficient cells.

Altenergy web is proud to offer these fine silicon solar panels. Below you will see panels made using single crystal silicon cells and multi-crystal cells. These refer to two different manufacturing processes. Single crystal, also called monocrystalline cells, tend to have higher efficiencies, but are more expensive to make, than multicrystalline cells.

Solar Panels From Altenergyweb
The top quality panels here are manufactured by a division of the multinational manufacturer, JA Solar, based in China (watch their stock on the NASDAQ, symbol JASO). The 125mm and 156mm monocrystalline and multicrystalline cells are carefully sorted and matched according to efficiency. This results in finished panels that offer a wide choice electrical outputs.  These solar panels give you a number of important features:

  • Wide variety of electrical characteristics make matching to existing systems easier
  • Choice of two sizes of silicon cells: 125mm x 125mm   and   156mm x 156mm
  • Vacuum encapsulated cells within laminations of EVA and Tedlar
  • Blue nitride anti-reflection coatings on cells
  • Standard nominal voltages 12v/18v/24vdc
  • Tempered glass 3.2mm (1/8 inch) covering encapsulated cells
  • Heavy aluminum frame to increase resistance to wind/snow loads
  • Drainage holes in frame prevents damage due to freezing/thawing of water trapped between frame and laminations.
  • Quick-connect interconnection cables are built-in
  • UL listed
  • CE certifications
  • 25 year power warranty
  • Power tolerance of ± 3%
Panel diagrams


How to Estimate the Number of Solar Panels Needed

Try the Altenergyweb Solar Panel Estimator . Jump to the article that tells what you'll want to consider and what information you'll need.

 

Power Ratings
The power rating, measured in watts, is the product of the maximum working current and the maximum working voltage ( W = Imp x Vmp ). One thing to pay close attention to when shopping for solar panels, especially inferior panels, is a power rating calculated using the short-circuit current and open circuit voltage. This results in a claim that is considerably higher than the true power that the panel will be able to deliver.

Ordering Panels
Choose the model number that best meets your needs and send an inquiry . If you need advice, I will be happy to help you. I will respond promptly by sending you a pro forma invoice with prices, shipping cost, and availability for the model and quantity you need. In most cases, panels are shipped directly from the manufacturer to save on shipping and overhead, and it enables me to offer them at the lowest possible prices.

Altenergyweb, LLC can ship internationally by air, land or sea. Ocean transport is considerably slower than air, but it is vastly more economical. If you need large quantities of panels shipped internationally, you can significantly reduce your total costs by requesting ocean transport.

I accept payment in the form of check, money order, or electronic funds transfer (EFT). Credit card payment cannot be accepted for international orders or for domestic orders by new customers with whom I have not yet established a relationship. Please make payment in US currency. International checks must be payable on a US intermediary bank. Your order will be initiated immediately upon clearance. EFT payments clear upon receipt and are the fastest recommended mode of payment, especially for international orders. Bank information necessary for making an EFT payment is included in the pro forma invoice.

Click on the links below to view all models and specifications.

(all data under standard test conditions of 1000W/m2,  1.5 ATM, 25°C.)

125mm Multicrystalline Solar Panels

156mm Monocrystalline Solar Panels

156mm Multicrystalline Solar Panels

 

Altenergyweb, LLC looks forward to helping you get started on the road to energy independence and greener living. 

 

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1. Anwar Arnold left...
Tuesday, 27 January 2009 12:58 am

Thank you .What are advantages /disadvantages both technically and costwise of a solar panel with the inverter fitted directly on the back of the panel ? You will be producing AC directly from the solar panel , I undestand.


2. PETER CANDROS left...
Tuesday, 2 June 2009 12:04 pm

I'm first timer in your site.I have to say a big thanks for the informations and the way you explain them.I have to do my home work for the system before I come back to your site Peter