Satellite/Google Maps Roof Online Calculators?

[Noob]

Most of the online satellite/Google Maps calculators seem to require personal information and/or a phone call / site visit / sales pitch. (1bog's lets you in, if you skip Facebook, but it doesn't actually tell you anything in the end.)

I found one that doesn't require info, at www.solarroofcalculator.appspot.com , but it's geared to Australia and calculates from the Southern hemisphere, in square meters, etc., with a fixed pitch value.

Are the results from there valid for my US home?

Are there any other online satellite map based tools we can use without registering (or more simple roof measurements/estimates I can take by hand, maybe up on the roof)?

Also, should I be concentrating entirely on the portion of my home facing south, and only deal with that "quadrant", not even bothering to consider covering (or drawing in with the tool) the other areas of the roof? My street/house/roof run at a 45 degree angle to the latitude, with the "back left" corner of the house pointing south. So the pitch across the south/southwest zone changes across the roof, and in fact I get clearer sun more towards the North, East/Southeast, and West portions.

More simply, is it a waste of resources to have panels facing anywhere but southwest?

I know installers can tell me all this but I'm trying to do my own research so I have some idea what they're talking about before I get overwhelmed with salesmen.

Thanks in advance.

Yours noobly,

Noob

[Naptown]

If the roof pitch is known and no shading exists google earth is a good resource as you can measure on the ground.
I do most preliminary estimates from there before going out and verify in the field.
Can't get roof pitch from google earth but there are smart phone apps that will do this (level by stanley is pretty good and free.)

[russ]

Try PV Watts http://gisatnrel.nrel.gov/PVWatts_Viewer/index.html

You can play with the orientation, pitch etc

[Noob]

If the roof pitch is known and no shading exists google earth is a good resource as you can measure on the ground.
I do most preliminary estimates from there before going out and verify in the field.
Can't get roof pitch from google earth but there are smart phone apps that will do this (level by stanley is pretty good and free.)

Neat, thanks. But again, should I be discarding any portion of the roof that is pitched/faced north or east? Maybe do separate calculations for multiple sections of the roof, treating them as separate entities at PVWatts et al., and then add them together? Or maybe it doesn't matter and I can tilt up the north leaning panels enough to make up for that portion of the roof's suboptimal angle. The peak of the roof's really safest from buildings and trees anyway.

Without installing Google Earth again I found https://www.daftlogic.com/projects-g...lator-tool.htm isn't bad for getting area; there are others. solarelectricityhandbook.com/solar-angle-calculator.html gives me a better idea about how the optimal angle changes through the year.

I gotta find me an old sextant.

Edit: whoa, thanks, Russ. The only PVWatts site I had been using was the old fashioned text calculator at http://rredc.nrel.gov/solar/calculat...atts/version1/

[Naptown]

The draft logic link is cool and already added to the bookmarks.
Solmetric has an app for the Iphone that will also give you an idea of what it will do for you. It's $40.00 but does almost every thing the $3000 version I have does.

[Noob]

The draft logic link is cool and already added to the bookmarks.
Solmetric has an app for the Iphone that will also give you an idea of what it will do for you. It's $40.00 but does almost every thing the $3000 version I have does.

Looks very cool, thanks. Too bad there's no Android version... but I just found https://play.google.com/store/apps/d...=search_result which is 16 bucks. (Found through the googles via a solar survey page at http://rimstar.org/renewnrg/solar_si...g_location.htm ). But it just uses compass/GPS/accelerometer, not camera, so I've no idea how it detects shade.

I didn't realize how deep this rabbit hole goes.

And oh my gosh what the heck is this thing?

https://play.google.com/store/apps/details?id=com.szlab.solarcharger&feature=related_apps#?t=W251bGwsMSwxLDEwOSwiY29tLnN6bGFiLnNvbGFyY2hhcmdlciJd

(hint: for best effect, read the comments and then read the description)

[Noob]

Try PV Watts http://gisatnrel.nrel.gov/PVWatts_Viewer/index.html

You can play with the orientation, pitch etc

Strange behavior on that map GUI version. No matter where in LI or NYC I click it keeps sending me to a cell in NJ.

But Version 1 of the site allows me to pick something like http://rredc.nrel.gov/solar/calculat...York_City.html

Was there a new solar survey that rendered the V1 site obsolete?

[Naptown]

Strange behavior on that map GUI version. No matter where in LI or NYC I click it keeps sending me to a cell in NJ.

But Version 1 of the site allows me to pick something like http://rredc.nrel.gov/solar/calculat...York_City.html

Was there a new solar survey that rendered the V1 site obsolete?

It is probably locating to Newark Airport or the closest weather reporting station to you