Today many window coverings offer homeowners a variety of sunning and shading options to make a living space look nice while saving on heating and cooling costs.
Energy-efficient window shutters have insulating values of R-2 to R-4, possibly doubling the insulating value of a standard, premium vinyl window with double-pane glass and a low-E coating (low-emissivity). Energy saving shutters are excellent insulators as well as perfect for redirecting sunlight.
Installing mechanical shutters that open and close automatically will keep sunshine from heating up your house in the summer and provide warmth when open in the winter.
Find more information at the U.S. Department of Energy website