The cost of efficient yet pricey LED light bulbs could fall by 50 percent in the next five years, according to the top Philips Lighting executive in the U.S.

Because of the efficiency and other features LED lighting offers, Philips Lighting is rapidly pushing into LEDs for both commercial and residential lighting, Zia Eftekhar, the CEO of Philips Lighting North America, said today in an interview from the LightFair industry conference in Philadelphia. The company projects that by 2015, 50 percent of its sales will be from LED lighting. It projects that figure would grow to 75 percent by 2020, a rate that's higher than the rest of the lighting industry, he said.

Philips EnduraLED A21

To bulk up its competence in LED lighting, Philips has acquired a few companies, including Color Kinetics and Lumileds. Yesterday, Philips Lighting said that its EnduraLED A21 bulb, designed to replace a 75-watt incandescent bulb, will be available in the fourth quarter this year for a price between $40 and $45.

The EnduraLED A21, which consumes 17 watts, offers energy savings and is projected to last 25,000 hours, or 25 times longer than an incandescent bulb. Over the life of the bulb, those savings make LEDs a better deal financially than incandescent lights, said Eftekhar.

Because residential LED bulbs are still relatively new, the price will fall as manufacturing volumes ramp up and the technology improves, he said.

"Take a look at what happened in commercial areas where the prices for outdoor LED lighting fell by 50 percent. If you asked me would those types of savings be a reasonable projection for (all LED lighting) over the next five years, my answer would immediately be 'Yes,'" Eftekhar said.

LED adoption will happen quicker in businesses because they typically spend more money on lighting and are more willing than consumers to consider the total cost of ownership, he said. Utility and municipal incentives for energy efficiency help lower the purchase price, too, he added.

"Clearly as we move forward, the cost will move downward. It comes from the quantity and the manufacturing experience and the technology breakthroughs that come with it," he said.

LED light quality as rated by the color rendering index, which is generally better in commercial situations such as retail, is projected to improve as well over time, he added.