Calculate your roof's potential solar power output with RoofRay

RoofRay is a fantastic new Google Maps hack that allows you to zoom in on any American address' rooftop, specify the surface area available on that roof for solar panels and then calculate the potential power of the system, in total and per square foot. You need to know some arcane details — I just guessed at the degrees of my parents' roof angle — but it's an excellent resource if you're trying to get a rough independent gauge on whether an investment in solar power would pay for itself any time in your lifetime.

RoofRay [Official Site via Treehugger]

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  1. Most solar installs use a rack system to optimize the array for the roof it is on. You can use your latitude, or if you are going for solar hot water, latitude +5 or 10 degrees to get more direct exposure in the early to late winter months. Latitude will give the best exposure for PV.

  2. Strange, the map near my home has an extra road that definitely doesn’t exist. The road isn’t in regular Google maps.

    Also, in areas where you can’t zoom in the last notch, it is impossible to mark the roof accurately.

  3. Not very accurate using Google Maps.
    I tried 2 homes and a parking garage.
    Calculation seems to be 35% overstating.
    Tried same building twice with different numbers
    Nice concept but not very useful.
    Suspect that the Google images are to crude

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