Solar panel positioning

Re: Solar panel positioning

dgassett wrote: »

How much power loss is there in positioning solar panels flat on a ribbed metal roof compared to a 25 to 30 degree angled using a racking method? I live in the DFW Texas area. Thanks Doug

Assuming a 30 degree tilt with a 180 degree azimuth for your tilted array and the same size array at 0 degrees tilt, PVWatts (http://rredc.nrel.gov/solar/calculators/PVWATTS/version1/US/Texas/) says you would lose approximately 11.2%.

Re: Solar panel positioning

Also consider dirt buildup and cleaning if installed flat. If at an angle, rainwater will wash off. As mentioned, hot panels = reduced output. They most certainly should be raised off the roof to allow air to cool the back of the panels. An angle would help that air movement.