Selecting Photovoltaic Modules and Inverters

Considerations for Selecting Photovoltaic Modules and Inverters


With so many different types of products on the market today for the solar electric (PV) industry, selecting the right module or inverter can be the difference between a successful system and a failed one. With the fast growth of the US market and other parts of the world, it seems that almost overnight the PV market has hundreds of companies to choose from when selecting product. Being that longevity is one goal in providing an extended return of investment (ROI) for projects, it is important to select the products from companies that you can trust will be around into the distant future.

Research can be a daunting task in regards to finding the balance of quality, longevity, and price — your distributor can be a great source of information when considering products for a PV systems. Your representative should be able to provide you with information about product warranty, quality of the product, price (often reflected in dollars per watt), and any technology implemented into the product.

As it relates to solar modules, the most expensive side to the system, a low priced module can get very tempting. While important, price should be weighed in conjunction to a manufacturer’s longevity; after all how good is a 20-25 year warranty when the company no longer exists? Additionally, there is a common miss-conception that module efficiency should be the deciding factor — efficiency generally only affects a systems size not performance. Efficiency reflects a modules ability to convert the sun’s energy into electrical power. For example a 200 Watt 16% efficient module vs. a 200 Watt 20% efficient module reflects a reduction in the system physical size by 20% but this will also most likely increase the cost of the module and therefore the length of ROI on the same 200 Watts of power. Until just recently, module technology was mostly based only on efficiency and material type, but now some electronic technology is implemented into the modules themselves increasing the modules energy yields, and power output.

Inverters are also a key function to the PV system and also typically the second most costly item of the system. Inverters contain many electronic components and over the years can be stressed to their limits, so selecting a manufacturer that has proven technology and a solid warranty can help save the installer a problem down the road. In the past the PV market has seen typically a 10 year inverter warranty and a fail period on the inverters in the first 15 years, however with today’s leading manufacturers these numbers are progressively getting better with 15+ year warranties and a fail period after the first 20+ years.

Product selection can take a significant amount of time, but with a good distributor relationship, on-going training, and a focus on longevity you can become a better installer with better projects and happier customers.

04/02/10,Michael Harvey- Able Energy Co.

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