my plan on growing a green curtian for high sun windows

We have several windows that face the sun most of the day without any shade, and unfortunately we can't plant any trees there to shade them.  In the summer this side of Washington gets HOT so I want to shade those windows to save energy and keep the rooms cool.

Here's more info on growing a green curtain:

http://lifehacker.com/5635574/grow-a-green-curtain-to-cut-down-on-cooling-costs

I have a nice old window box and I'm going to plant pole beans all through it and place in front of the windows.  They will grow up a wire trellis and cover the window in nice green leaves.  You can use any vine plant but I want something that produces food. 

I will post pics when it actually warms up enough to plant my beans.