How can you best quantify the financial value of a module with a better warranty?

Southern Solar,

It seems like the answer, from a financial standpoint, is pretty straightforward: You simply change the degredation rate in your financial model and then you'll have approximately 3% higher production at year 25 for the QCells. That being said, there are two more factors to consider:

• How do the other terms of the warranty compare? For instance, is PID or Potential Induced Degradation, which is affected by climatic factors, specifically excluded from the warranty?
• Will the manufacturer or an underwriter of the warranty be in business in 20 years to honor a warranty claim?

Here is a useful paper from NREL which makes some very good points about average degradation rates of PV products over the years: http://www.nrel.gov/docs/fy12osti/51664.pdf

The first thing to consider, which Q Cells stresses, is that quality is the best warranty, and Q Cells's quality is really unsurpassed in the industry.  They use best practices in manufacture, stringent quality controls, and their ultimate product reflects that leading quality.  Their 0.0025% claim rate since 2010 further supports their reputation for quality.  With this commitment to quality, Q Cells is confident in extending an industry-best warranty.  

Turning to your question directly, the ultimate math and resultant risk profile will obviously be project- and location-specific.  Nonetheless, using averages and some assumptions, we can begin to distill the dollar value of Q Cells quality.

A 2013 NYTimes article cited Chinese failure rates at between 5% and 20%.  Assuming a 5% failure rate over a 25-year life, and a 100kW system, that's about 20 modules failing during the generator's life, or roughly one per year.  Using a Q Cells module, with its 0.0025% warranty claim rate, one can expect dramatically reduced ongoing O&M and module replacement costs.

As to Q Cells modules' superior longevity and reduced degradation, we can similarly divine the monetary value of Q Cells quality over the life of the generator's energy production.  Assuming a 1MW system, and assuming it receives 4 solid sun hours per day, it can be expected to produce ~1,460MWh/yr.  Given that the Q Cells will degrade at a 0.1% slower pace than the competition, we can find the value of the spread.  The 0.1% spread on 1,460MWh/yr is 1,460kWh.  Assuming a retail cost of $0.10/kWh, the Q Cells excess production is worth about $150/yr, or about $3,750 over the life of the system.  Not insignificant!