I've never heard that Solar Shades are to be used on the exterior only and I've seen plenty of use on double pane windows within the house. If a shade had an insulating effect and was sealed along the edges or had sealed side tracks, then that would not be safe to use with double pane. Solar screens are just that.....screens. They go outside the window just as any other type of screen is used. Roller shades can be decorative lightweight window coverings, but the term 'roller' is also used for the Solar Shades since they are usually on some type of roller system. It sounds like Solar Shades will fit your need. Here is a link that might be useful: Interior Shades

We are planning solar shades (designer screen shades I think Hunter Douglas calls them) for our Master bedroom. We put them in recently in the guest bathroom and the office without a liner/second shade, but the window treatment guy suggested "micro-pleats" to use behind the solar shade in the bedroom. We're not worried about privacy there (windows are in the back and driveway side of the house, upstairs), rather, we want the ability to darken the room/prevent early-morning sunlight from coming in through the solar shade. HTH!

slowjane, we have a retractable awning for an east facing room on our house in Northern California and we love it. We were using the room as a nursery and in the summer it would be uncomfortably hot by late morning just when the baby wanted a nap -- the awning solved that. As a bonus, our patio is now useable in the summer. Ours was probably around $1000? ordered through Costco, but it is motorized and I'm guessing it's 12-15 ft wide (it spans a set of French doors and two additional windows). I'd guess you might get a manual retractable awning for a single window for a lot less? Good luck.

I recently installed them along with UVA blocking film on the window. I wanted to preserve the view and not feel that I was in a tomb when they were down so mine aren't massively opaque and the film is not apparent at all from exterior or interior. I have a very strong Eastern exposure and without the shades/film the morning would be unbearable even with the A/C running full blast. I am in Los Angeles so even in the WINTER if there was strong sun and moderate temperatures, it would heat up like a greenhouse almost. With the installation, temperatures remain moderate even when the direct sun is pouring in and based on tentative comparisons to prior electric bills in the same months, I appear to also be saving some money on energy costs. I installed the film because I wanted to protect my stuff from as much sun damage as possible as some of my stuff had "fried" in the direct sun prior to the remodel.