I was reading about solar drapes while researching my other big solar air heater project.
Solar Heating Drapes, Solar heating drapes - Solar Electric
So I thought I'd try using some materials I had lying around on some windows that catch alote of sun.
Too bad I only have two small windows that face south.
In one room we use for storage I coverd a double window that faces east with some black plastic weed control fabric. Also, on the stationary part of my patio door that faces west I put up a big piece of leftover pet screen material that I used for the seat of my recumbent bike project. Both set-ups seem to warm up nicely when getting full sun. The weed control fabric doesn't allow a view though.