Doing your homework when choosing a photovoltaic system

By Hawaii Renovation Posted in: EnergyExteriorRoofing

There are many reasons to do your homework when choosing a photovoltaic system, and Pacific Islands Construction believes that an informed buyer is going to make the best decision for themselves.

The following information is provided to give some clarity to what you may be provided when looking at various equipment:

1.The PTC test indicating the efficiency of one manufacturer over another is unreliable and should be discounted. The testing does not truly reflect real-world conditions and is performed on modules hand selected by the manufacturers to reflect higher values or performance.

Under laboratory conditions, the equivalent of 100 candle lights is flashed on a module and a reading is taken to the efficiency of the module. The reading is then used by the manufacturer to determine how much power the panel will provide. The information would be useful if it truly reflected real-world conditions such as high module temperature, humidity, UV degradation, poor cell performance of the cells in the modules, and what the average module (not the hand selected) will perform at.

2.The Underwriters Laboratory (UL) approach of taking modules off the assembly line unannounced as much as four times a year is a better way to test a product’s true average performance. The UL seal of approval is given only if the UL can show up at the factories unannounced and pull products off the assembly line for testing. In their opinion this is the only way to ensure the product is continuing to be produced at acceptable standards they have previously tested for.

One thing they test for is the plastic backer material, which is one of the more expensive components of the modules. UL uses a spectroscope to compare the original composition to that being produced to ensure that the manufacturer has not substituted a cheaper plastic that can been seen under close scrutiny.

3.Roof flashings and securement of racking system to a structural element such as rafters is critical. Only allow roof flashing made for your type of roof and do not allow your roof to be punctured numerous times only to be flashed by installing sealant around the penetration. It will void your roof warranty and will eventually leak.

4.For every degree in Celsius the modules get hotter than 77 degrees F, the efficiency decreases by 1/2 a percent. How the modules are installed to promote ventilation is critical.

5.Modules should be cleaned from time to time to keep efficiency levels higher. The frames will also last longer if cleaned of possible contaminants.

6.Solar modules warranties are provided in two forms: one for the power efficiency, and the other for panel construction. Generally, consumers are told that solar modules come with a 25-year warranty. This is deceptive. Warranties are written for manufacturers, not the consumer, and they should not be construed as a guarantee.

7.Module efficiency can be lower than listed rating as shown by power tolerance, peak power or pmax rating. A negative value of plus (+) or minus(-) 5 percent could mean you are getting less power than the rating for the module or system as a whole.

8.Studies have shown that the energy produced by photovoltaic modules depreciate on average about .7 percent per year. Some manufacturers have a track record indicating a better performance than this average.

Pacific Islands Construction has initiated a program where it is donating some of the profits from every sale to support the “Book Trust” program. The program provides books selected by students to children from low income homes. This is an opportunity to provide a life-changing moment that encourages children to read at a younger age.

To contact Pacific Islands Construction or to find out more about “Book Trust,” call 8417756 or visit our website at pacificislandsconstruction.net.

Contact: 841-7756
Website: pacificislandsconstruction.net