When discussing prices, an essential point is often ignored: How do the modules perform in reality?
Although different modules may have equal power ratings (at STC = Standard Test Conditions, Irradiation on module surface 1000W/m² with spectrum AM 1.5 and cell temperature 25°C), they can differ substantially in their energy yield.
By comparative monitoring of various photovoltaic installations, it has been shown that systems based on large-area modules of the type ASE-300 achieve exceptionally high yields in energy.
This fact is particularly obvious in the RWE Environmental Tariff program. Within the scope of this program, 25 photovoltaic installations with a total power of more than 1 MWp have been built by different manufacturers.
The energy yields of the installed systems are continually recorded and the data is available. We have evaluated these data. The following graph shows the annual amount of kWh fed into the grid with respect to the kWp, the installed rated power of the generator.
All the grid-tie installations in operation since August 1997 have been incorporated in this comparison. Photovoltaic installations based on the ASE-300 are distributed through the entire electric utility region of RWE and, therefore, are located at sites with higher as well as lower solar irradiation.
The above chart illustrates that installations based on ASE-300 modules achieve energy yields which are approximately 20 to 25 % higher than average. Taking into account the higher efficiency of the inverter (Sunways) used here, we can expect the performance of the modules to be 15 to 20 % higher.
*performance measurements based on international standards (3 % more than the 1997 module based on ESTI/ISPRA standards)
*large modules with 216 closely selected cells resulting in installations with fewer modules and wiring losses.
*minimized deviation of nominal power (± 4 %) through serial connection resulting in lower mismatch losses.
*Multi-Contact plugs that allow fast installation as well as safe low-loss connection.
The large ASE-300 module (2.4 m²) also reduces support structure costs and installation time.
Remember these advantages when you compare prices!
Dear Building Owner,
You may have heard that solar electric (photovoltaic) systems are increasingly finding their way onto rooftops across the United States. The President has called for solar systems to reside on top 1 million roofs by the year 2010 as one goal towards addressing global climate change. Fortunately, the solar industry in general and RWE SCHOTT Solar in specific have been working with related standards to ensure that the photovoltaic (PV) systems are safe.
ASE's PV modules are fully covered by Underwriters' Laboratories UL 1703 (Flat-Plate Photovoltaic Modules and Panels)-- standard for the PV modules -- and the Institute for Electrical and Electronics Engineers IEEE 1262 (Recommended Practice for Qualification of Photovoltaic Modules) for performance and reliability.
UL 1741 (Static Inverters and Charge Controllers for Use in Photovoltaic Power Systems) is the proposed standard for PV inverters (the devices that convert the DC from the Module to the AC of the grid). The electrical systems should comply with National Electric Code NEC article 690 and the structural designs should comply with the Uniform Building Code (UBC). There are a number of commercially available products and system designs from the PV industry that comply with most of these standards.
Fire is a major concern among building inspectors. PV modules placed on roofs are required to carry the same, or higher, UL fire rating as the roofing material itself. There are three classes of rated roofing, Classes A through C; Class A being the highest rating. Therefore, Class C roofs only require modules with Class C or higher. Class B roofs can carry Class B and higher and so on. It's our understanding that, according to the Uniform Building Code, most commercial roofs in the U.S. should use Class B or higher roofing material.