South or West ?

billybob9

If your on the Grid and your Electric company is charging you EXTRA from 4pm to 9pm wouldn't it be better to face your panels west where the sun goes down to get that extra power from your panels ? If someone did the math this might be the way to go and decrease the need for a battery back up. When I did one of my "how low can you go" tests I was getting power till the sun set. BG

BB.

Yeap... Local weather conditions (cool mornings, clear air, good harvest; vs summer afternoon thunder storms)... Or live in an area with morning fog/marine layer that burns off for clear afternoons.

You can play with PV Watts and The Solar Electric Book calculators--Especially useful if the monitoring sites are near your location/have similar weather patterns. PV Watts allows you do download into a spreadsheet so you can play with the numbers.

https://pvwatts.nrel.gov
http://solarelectricityhandbook.com/solar-irradiance.html

My theory--Unless you see a >10% difference between "good" and "bad" predictions--Then don't sweat the small stuff.

-Bill