Will the screens darken the room?
They still allow plenty of light to come in. As a bonus the light that comes thru is much softer on your eyes and
reduces that awful glare on your television set.
Plants do well in the softer light as well.
How much money will I save with the screens on?
Some studies show up to 50% on your cooling portion of the elecrtic bill. Usually screens pay for themselves
in 2 years or so. It will be tough to find a home improvement that will pay for itself and not cost thousands of dollars.