The Cost Of Clean Power
Of the three distinct formats of marine solar panels, the aluminum-framed glass panels are the least expensive, as they use a standardized construction process. The semiflexible and walk-on panels are highly specialized items made in small quantities, so they're more expensive. Genuine high-grade SunPower back-contact monocrystalline cells are currently the most efficient ones available and give a higher daily yield, but at a premium price. Amorphous panels are relatively inefficient panels and command a high dollar-per-watt price for their ability to be placed on rounded surfaces.
"There's a world of difference between true high-performance marine solar panels and those used on residential and commercial properties. Prices reflect that. While a small system designed just to stop a battery self-discharging will cost less than $300, a higher-capacity setup will cost in the thousands.
A good rule of thumb? Buy the most efficient panel you can afford. Many environmental conditions (fog, smog, clouds) can reduce the efficiency of solar panels, and if you start with a low-efficiency panel and experience less-than-perfect conditions, you may be unhappy with its performance.
Current output is determined by the quality of the available sunlight. Manufacturers provide efficiency ratings for their panels; be sure the numbers are derived following standard test conditions (STC), which represent the "ideal solar conditions" for maximum performance, so that you can accurately compare one panel to another.