I’m signing my contract with Solar Liberty tonight so as far as I’m concerned it’s done. No need for anyone from CIR to call me. I’ll keep updating this thread with my experience though. I will say I’m not at all impressed by Seraphim’s sales guy saying they make their panels in Japan where there is NOTHING online to back that up.
I’ve also been playing with the PVWatts calculator.
My raised ranch has a standard 4/12 roof (learned all about this when I put a roof on in 2013) so 18.43 degree roof angle, 270 degree orientation (west). The array would be a fixed roof mount for any installation. Almost zero shading issues (no shade until shortly before sunset when the power from the sun is really low anyway).
When I plug in the numbers for the Solar Liberty quote, 9kW system, even when selecting standard module type vs premium (the Hanwha panels they’re installing are 18% efficient, which is much closer to the calculator’s premium of 19 vs it’s standard of 15). I’m not touching the 14% system loss which I know is probably high for a brand new system. The result? 9444 kWh annual production. Solar Liberty says it will produce 9158 kWh but they said they estimate low because they want to make sure a year from now I’m not going back to them saying, “You said it would produce X but it only produced Y”. I respect that.
When I run these the same calculations (using a standard panel) for the CIR 8.64 kW system? 9067 kWh per year. CIR says it will produce 9633 kWh. Bumping the calculator to a premium panel (which it’s not, the PDF from Seraphin says their 320 cell is only pushing 16.5%) only gets me to 9103 kWh. To get to their 9633 kWh number I have to select a premium panel and drop the system loss down from 14 to 9. The numbers don’t seem to add up.
If I give the Solar Liberty system the same premium panel selection and only 9% loss the production jumps to 10,043 kWh.
PS… when the Seraphim sales guy says, “Ours have higher module efficiency and are made in Japan. Theirs’s have lower module efficiency and are made in Malaysia” uhe might want to get a PDF up online that proves it. This is the only 320w panel Seraphim has specs for online and it’s 16.5%
VS the 300w Hanwha panel I’m going with that has an 18% rating: