We get asked a lot why your solar panels cost Rs. X when so and so in the market is selling it for so much less at Rs. Y.
The simple answer is – Not All Solar Panels Are Equal.
So when you compare prices for solar panels (and we do encourage you to shop around), you do need to pay attention to 2 key aspects of the panel’s quality – GRADE and MANUFACTURER TIER.
GRADE refers to the quality of solar cell used in the solar panel, and are categorized as A, B, C, or D. Grade A cells are the highest quality,in that they are tested against highest quality criteria to ensure there are no micro-cracks in the solar cell, and all the cells are of the same type. The quality diminishes for grade B, which may have micro cracks and not all cells are of the same type (they sometimes mix and match). Grades C and D are much worse quality with larger cracks and chips, and the cell mismatch is even worse.
A typical solar cell will be exposed to sunlight throughout its lifetime. Sunlight contains harmful ultraviolet (UV) light that deteriorates all materials, including solar cells. The tiny flaws in the material become worse after prolonged exposure to sunlight, and its power output reduces over time.
As a grade A cell has the least flaws to start with, its deterioration will be the slowest.
MANUFACTURER TIER refers to how automated a manufacturer is in its manufacturing process, its manufacturing volume, how long it has been in the industry, and how much it invests in R&D. There are 3 tiers to classify this:
- Tier 1 manufacturers are the top 2% of solar manufacturers, normally producing over 1 GW of solar panels in a year. They are vertically integrated meaning they make their own cells and wafers. They invest heavily in R&D, and have advanced robotic processes for manufacturing. They have been manufacturing panels for longer than 5 years.
- Tier 2 manufacturers are small to medium scale manufacturers, with little or no investment in R&D. They only use partial robotics in their manufacturing process, and rely more on manual work from human production lines. They have been producing panels for 2 to 5 years.
- Tier 3 manufacturers are actually just Assemblers – i.e. they assemble other manufacturer’s cells into a panel. This is 90% of the new solar PV companies, with no investment in R&D, and they use human production lines for manual soldering of solar cells instead of advanced robotics. They have been assembling panels for 1-2 years. (source: http://www.energymatters.com.au/choosing-solar-panels.php )
You get best (and consistent) results from Grade A panels manufactured by a Tier 1 manufacturer. They may cost a little more on a per-watt basis, but when you consider the energy output and the longevity of their panels, you actually get more energy out of Tier 1 / Grade A panels than anyone else. And ultimately, you have to ask yourself what matters to you more — the total number of watts of a solar panel, or the actual kWh (units) of energy produced by the panel?
That’s why we at Gham Power use Grade A solar panels from Tier 1 manufacturers like LDK Solar, which ensures the best overall value in terms overall electricity output and long-term high quality.
Here’s a more detailed video from Energy Matters site that explains this further: