15 percent of all worldwide electricity use goes into lighting and there are several billion sockets around the globe that still contain an incandescent light bulb. One of the best investments that developing and emerging economies can make is to switch from the inefficient incandescent light bulb, which is a technology that hasn’t changed much in the past 125 years, to super-efficient LED light bulbs. While these old-fashioned bulbs will still be available for purchase in developing countries, in developed countries of Europe and North America these energy-guzzling bulbs are due to be phased out in mid-2018 and 2020
LED bulbs are amazing products as they use 85 percent less energy to produce the same amount of light as the old incandescent did. So instead of using the old 60-watt incandescent bulb, one can switch to a 10-watt LED bulb. The energy-saving bulbs come in numerous shapes and light output levels, are dimmable, more shatter-resistant, and last up to 25 years under normal operation of three hours per day.
Shifting to more efficient appliances and air conditioners can take more than a decade for the existing stock to turn over, or for the switch to electric cars which will take even longer, installation of more energy efficient lighting can happen far more quickly as the old incandescent bulbs burn out within a year or two.