The NECA-IBEW Electrical Training Center, maintained by IBEW Local 48 and the Oregon-Columbia NECA Chapter, is located on Airport Way in Portland Oregon, just a short distance south of the Columbia River.

On the south and west sides of the building are photovoltaic arrays. The arrays have the same number and type of modules. The arrays were installed at the same time, wired by the same people with the same methods, and tests indicate they have the same efficiency. Both are in good working order.

As expected, the west array generates about 90% of the south array's output on a sunny summer early afternoon.

Here's the puzzle: Annual average output of the west array significantly exceeds that of the south array. I know why. Do you?

 

Got me, I grew up in Sandy (western side of Mt. Hood), seemed to be raining or snowing most of the year. Just a few months of daily sun during the summer. Would think solar a good investment. Portland was only 30 or so miles away...

 

Hint: has to do with location.

 

Plane of the elliptic, how the sun swings across the sky?

 

Don't tell me its down in the Columbia River Gorge.

 

Also, there is the odd tree or two in Oregon.

 

Or Mountains.

 

I'm guessing it has to do with fog and overcast which I believe is very common in the Portland area, especially near the river, and typically burns off in the afternoon.

 

I'm guessing it has to do with fog and overcast which I believe is very common in the Portland area, especially near the river, and typically burns off in the afternoon.

Ron knows his meteorology!! The morning fog along the river is indeed the culprit.

 

They need to build a huge dehumidifier so their solar panels work!

 

I wonder if we could build a solar-powered dehumidifier...

 

You'd have to, otherwise it wouldn't be a "Green Project".