I was recently contacted by Andrew Mackenzie about the iPhone app he created called the Sun Tracker. I downloaded the app and I'm extremely impressed. (he gave me a free trial license but regular cost is $14.99) With just your iPhone you can get an excellent idea if solar will work in your location.
From the Sun Tracker user manual, which is an in-depth overview of how the product works:
By utilizing the compass and inclinometer functions of the iPhone, together with the built in GPS and sun positioning algorithms, Sun Tracker can perform shade analysis in seconds. It is fast simple to use, and quick to deploy, with no alignment or set-up time.
The Sun Tracker is a great example of how powerful the iPhone can be and shows that not only can this device play games, music, and phone calls, it can also help clean energy! Disclaimer: I am a big fan of the iPhone.
After about 15 minutes of looking at the user manual, I was able to go out and do a quick 5 minute survey with my iPhone and the Sun Tracker app during part of my lunch break! As you can see it looks like a pretty good spot for solar! An image from the Sun Tracker site survey that I emailed myself from the app can be seen below:
The vertical lines at the bottom that range from 90 - 280 degrees (the X-axis is in degrees) represent the outline of the skyline that I did with the app. You use the built in camera on the iPhone 3Gs to trace a view of the horizon, starting in the east (90 degrees) and rotating your body 180 degrees to end up in the west: east-->south-->west. There is only a small period of time in the morning during winter that the skyline blocks the sun. You can see this around 120 degrees. Other than that the solar panels would have an unobstructed view of the sun!
One of my only complaints would be the heads up display (h.u.d.) - that you use to trace the outline of the skyline - does not have a display of a compass on it. It does show degrees on it as you rotate, but I wasn't absolutely sure that the degrees displayed on the h.u.d. corresponded with degrees displayed on the iPhone's compass.
To ensure I was actually facing due east, I used the iPhone's built-in compass to first align myself due east, then opened up the Sun Tracker app and pulled up the h.u.d. just to guarantee I was in the right starting spot.
There are other devices out there that do the same function. One is called the Solmetric Sun Eye. While the Sun Eye may have a little more functionality, it is also about 20 times more expensive than the Sun Tracker iPhone app! This would be a great application for a solar company to give to their iPhone-enabled sales staff to do a quick assessment on-site.
Great job Andrew!