TIL. Just sharing. I think I worried too much about the importance of the panel angle to the sun. I'm stuck at a fixed 20 degree angle with worst-case azimuth 225 (south-east).
The DoE calculator enabled me make the financial case using real-world yearly data.
US Department of Energy PV Watts calculator: https://pvwatts.nrel.gov/pvwatts.php
Article explaining the PV Watts calculator: https://www.thesolarnerd.com/blog/optimal-solar-panel-tilt-most-calculators-are-wrong/
So... in ~43 degree latitude Boston azimuth 225 the yearly difference in generated power seems to be negligible between 20 and 45 degrees.
20 degrees, yearly kWh = 14,341 Dec 635kWh Jul 1579 kWh
45 degrees, yearly kWh = 14,447 Dec 781kWh Jul 1441 kWh
Azimuth 180 (South) only makes a 5% - 7% yearly difference:
20 degrees: 15,028 kWh ~= 5% better
45 degrees: 15,605 kWh ~= 7% better
Better tilt angles would be nice, but the main thing is that putting solar above my patio seems financially feasible.
I can actually build something with a 20 degree slope over my patio!
Anyone come to a different conclusion?
The DoE calculator enabled me make the financial case using real-world yearly data.
US Department of Energy PV Watts calculator: https://pvwatts.nrel.gov/pvwatts.php
Article explaining the PV Watts calculator: https://www.thesolarnerd.com/blog/optimal-solar-panel-tilt-most-calculators-are-wrong/
So... in ~43 degree latitude Boston azimuth 225 the yearly difference in generated power seems to be negligible between 20 and 45 degrees.
20 degrees, yearly kWh = 14,341 Dec 635kWh Jul 1579 kWh
45 degrees, yearly kWh = 14,447 Dec 781kWh Jul 1441 kWh
Azimuth 180 (South) only makes a 5% - 7% yearly difference:
20 degrees: 15,028 kWh ~= 5% better
45 degrees: 15,605 kWh ~= 7% better
Better tilt angles would be nice, but the main thing is that putting solar above my patio seems financially feasible.
I can actually build something with a 20 degree slope over my patio!
Anyone come to a different conclusion?