Consumer Reports asks, “What if the lightbulb you put in your baby's nursery didn't have to be replaced until Junior is off to college? That's the promise of LED lightbulbs.” According to the US Department of Energy “residential LEDs use at least 75% less energy, and last 25 times longer, than incandescent lighting.” On a national scale, “by 2027, widespread use of LEDs could save about 348 TWh (compared to no LED use) of electricity: This is the equivalent annual electrical output of 44 large electric power plants (1000 megawatts each), and a total savings of more than $30 billion at today's electricity prices.” https://www.energy.gov/energysaver/led-lighting
The variety of available LED lighting has never been greater, and prices have come down in recent years, so that switching from incandescent to LED quickly pays for itself. Some of the major manufacturers of LED bulbs provide online calculators that give an indication of potential savings. Here’s an example:
http://creebulb.com/calculator