The practical challenges of solar power
Okay, so there’s some obvious challenges, such as when the sun don’t shine. But beyond that, getting the optimum potential out of solar is something of a black art, as this post highlights.
“So the ‘100-watt module’ output, reduced by production tolerance, heat, dust, wiring, AC conversion and other losses will translate into about 68 watts of AC power delivered to the house panel during the middle of a clear day (100 watts x 0.95 x 0.89 x 0.93 x 0.95 x 0.90 = 68 watts).” From A Guide to Photovoltaic System Design and Installation (PDF) by the California Energy Commission. If you are interested in solar, you need to read their report.
But this 68 watts is only part of the story. If you have battery storage on the system they say it could reduce the power another 6-10 percent. They then stated that poor installation layout problems–including shading can take an additional toll. Another big issue is the angle of the roof and the direction it faces (in California, where your roof faces can affect the power output up to another 15 percent for many roofs).
