In 2012, expect to see ordinary windows being converted into solar panels with the application of a film from 3M.

According to 3M, the see-through film is arrayed in narrow, translucent green strips with gaps between them. They are then glued to windows.

The film is made from an organic photovoltaic material which is printed in sheets. While it is transparent, the film blocks or absorbs about 80% of visible light and over 90% of infrared light, providing a degree of shade.

A square metre of the film can generate roughly enough electricity to charge an iPhone under peak sunlight, but still allows for high visibility.

The efficiency of the film is fairly low, generating only about 20 percent of the electricity that a traditional silicon solar panel does. Initially, it will also cost about half as much as a real panel. As production ramps up, the cost will come down.

An advantage is that the film is easier to purchase and install and takes up no additional space.