Does painting your roof white offer significant energy savings?

I wasn't able to find any significant data, but one thing to keep in mind would be how you're defining "savings". What you probably want to look at is the annual net savings in energy costs (or carbon emissions, depending on what your goal is), which needs to offset the energy savings in the summer against the (hopefully much smaller) increase in winter heating costs due to the significantly decreased conversion of sunlight to heat energy.Whether painting a roof white will make sense overall depends on the climate, but also on the comparative cost/benefit of more traditional energy-saving improvements, such as upgrading the home's insulation, windows, and heating/cooling appliances. These types of upgrades will offer energy savings throughout the year, as opposed to the white roof which is only beneficial in warm months and actually detrimental to the home's energy efficiency in the winter. For new construction, the options become even greater.(One additional caveat: Snow completely changes the equation as well, as the roof effectively becomes white, thereby absorbing less sunlight to convert to heat, but the snow also acts as a layer of insulation that slows the loss of heat from inside the home through the roof.)