Facts About Solar

Archive for the ‘Used Solar Panels’ Category

Most consumers are not aware they could for instance be paying for 200 Watt solar panels while only getting 180 Watt out of those same solar panels! This discrepancy is known as “peak tolerance rating” (PTC Rating) in some cases known as “minimum warranted power “or” negative tolerance rating. When shopping for solar panels, what you want to look for is the highest minimum warranted power rating, the lowest negative tolerance rating or the lowest peak negative tolerance (PTC) rating.
A solar panel manufacturer may claim their panels have a high efficiency rating but their claim maybe worthless if the solar panel has a poor minimum warranted power or a low (PTC) rating. What all this means is that the solar panel manufacturer offers a warranty that states that their solar panel’s actual power rating will not be less than a certain rating out of the box. So, if a 200 Watt solar panel has a negative tolerance rating of 10% then their 200 watt panel is guaranteed not to have a power rating of less than 180 Watts right out of the box.
In my opinion 10% or even 8% isn’t really that great when there are other solar panel manufacturers who produce solar panels with a negative tolerance rating of only 5%. Therefore, remember while shopping for a solar system, you may hear solar dealers boast about their solar panel’s high efficiency or higher PTC rating or better performance in hot weather. Always ask what there panel’s negative tolerance rating is and if theirs isn’t less than 8%, consider another panel manufacturer.

PTC rating of solar modules

Here’s a Smart Tip! When shopping for a solar electric system, always insist on seeing the solar panel’s specification sheet and look for the minimum warranted power rating so you can accurately determine the power that panel is guaranteed to produce on an optimal day of sunshine.

Additional info:  http://solarutilitiesnow.com

It may seem like the whole world is turning towards solar for electricity generation for their homes and businesses.

For many people even though the price is coming down, it is still very expensive to install.  Finding a good source of used solar panels may seem like the best way to maximize your purchase power so that a solar generator can be installed in your home or place of business.

Here are some important facts. Solar panels (“modules” their technical name) lose their ability to perform over time. This is called degradation, which means simply that most modules loose a small percentage of their ability to turn sun light onto electricity each year, commonly known as “derating”.

Therefore, when buying used modules the buyer should know the derate factor of the module they are buying. Next the buyer needs to know how long has the module been in operation, so as a buyer you can determine how much of this modules production ability as been lost.  Example: a derate factor of 2% means the module will lose 2% of its production ability each year on average. So… if you are buying a 150 watt module that is 10 years old, you would subtract 2% a year for each year of its life. Example for year one (150 w x 2% = 3 watts).  So what will your 150 watt module produce today?  If you do the math it should be around 122.5 watts.

This is very important information when designing a solar system. Think of it like this, simply installing a few solar modules to your home or business without knowing how much energy they will produce may leave you well short of your expected goal of eliminating your current electric bill. If you need to produce 3000 watts of energy with solar and you buy 20, 150 watt modules to accomplish your goal, yet they only produce 122.5 watts each you would only produce 2450 watts or 550 watts short of your needed goal.

Stay tuned for more on solar system design. or visit my website site  http://solarutilitesnow.com