Does more efficiency actually pay

Paying Less and Getting More

Consumers have many different solar panels available to use under the CSI (California Solar Initiative). With so many different solar products available, it is easy to get confused on which panels to purchase. Several factors need to be incorporated into the final decision on which solar panels to use.

What is the efficiency of the panels? This is important because efficiency translates into more annual killowatt production versus a less efficient system.
This also translates into a higher rebate due to CSI's policy to base rebates on estimated energy production.

Do more efficient solar panels translate into higher overall pricing? Yes it does. However where it really increases in pricing is from panel efficiencies from 15% to 18%.

Do the extra costs incurred upfront pay additional benefits over a 5 to 7 year period. The answer is no. The following breakdown is of a Sanyo hybrid HIT210 watt panel (17.1% panel efficiency) and a very good Schuco 210 watt SMAU1 panel (14.9% panel efficiency).

The major deciding factor on the two panels is the pricing. Sanyo with its hybrid panels cost more than the Schuco panels. When the dust settles after pricing, rebates and annual KWH production, the customer's can realize the following:

Number of Panels 42 Sanyo 210 HIT versus Schuco 210 SMAU1
Internal Rate of Return 32% versus 39.7%
Pay back in years 6 years versus 4.8 years
Total Annual KWH 14,106 versus 13,970
Total CSI Rebate $5,108 versus $4,932
Total System Price $59,535 versus $48,510

Finally the warranties. When warranties are compared, Sanyo is less confident with their product as it only has a 20 yr warranty versus a 25 year warranty with Schuco. The tolerance rating for Sanyo is -0 to +10% which is excellent. However, after the first day on the roof, the warranty drops off to -5% to +10%. The -5% now makes this warranty less than average. Schuco has a -0% to +5% tolerance. Their warranties start at the panel rating while Sanyo starts at -5% (after day 1)from the panel rating. Sanyo guarantees 90% output up to 10 years from installation while Schuco offers 90% up to 12 years from installation.

Based on the internal rate of return, the payback, the small differenct in overall KWH production and rebates, and the much smaller price and better warranties, it is easy to see why most people would choose a very efficient panel like Schuco versus a super high efficient Sanyo panel.

The bottom line is more efficiency is a good thing to have, but if pricing is not competitive and or the warranties are not as good as most other panels, then the extra efficiency may very well not equate into a better "value".