Should I care about payback period?

[jboy210]

how has your production been compared to their estimate? I’m in Texas with an east facing roof at 23 degrees slope with no shade and pvwatts estimates production much higher than what Tesla estimates. My electricity is through a co-op at a flat 9¢ (No TOU) with net billing (not net metering). They buy it back at about 50% of what they charge. Anyway, I’m doing all this math and using the info from our smart meter also, but I’m trying to figure out if Tesla just low balls their estimates or if their set ups are just less efficient than PVWatts’ default efficiency.

Tesla leaves themselves some margin to ensure they can met the warrantied performance. Also, they do package systems they can install quickly. People have ordered the larger package and cut back to what actually fits on their roof.