It can definitely make a big difference. DC’s latitude is 38 degrees. That’s about the same gap to Miami (25 degrees). Think about shining a flashlight perpendi

It can definitely make a big difference. DC’s latitude is 38 degrees. That’s about the same gap to Miami (25 degrees). Think about shining a flashlight perpendicular to the ground vs at an angle. Beyond the dynamics of direct irradiance, there’s also weather to consider- if you live in a significantly cloudier area (which might be possible, assuming you live in Canada or Germany/netherlands/etc based off that latitude), that will obviously affect output. And then there is also things like building-to-building shading, in case you live in a dense area… lots of things can affect this kind of calculation. Try playing around with the National Renewable Energy Laboratory’s PVWatts calculator: https://pvwatts.nrel.gov/pvwatts.php https://pvwatts.nrel.gov/pvwatts.php