Credit: Wikimedia Commons.
An estimated 12 percent
of the electricity consumed in this country is used for lighting. This represents a huge opportunity since, until recently, most lighting was based on incandescent technology, which depends on heating filaments until they are white hot to produce light, a process that is very inefficient. Newer technologies, such as CFLs (compact florescent lamps) and now LEDs (light-emitting diodes), offer far more efficient light production as well as substantially longer life. But prices are still high. The bulbs do pay for themselves over time, and sales have been steadily growing. But the pace could be quicker.
Based on a new report
by the U.S. Dept. of Energy, LED lamps and fixtures installed in the United States have increased 10-fold over the last two years -- from 4.5 million units in 2010 to 49 million units in 2012. These new installations, including everything from recessed lighting to streetlights, are projected to save about $675 million in annual energy costs. At the same time, the cost of an LED replacement bulb has fallen by about 54 percent. DoE estimates that switching entirely to LED lights over the next two decades could save the United States $250 billion in energy costs and reduce electricity consumption for lighting by nearly 50 percent. By 2030, LEDs could come to represent 75 percent of all lighting sales. The resulting energy savings would be enough to fully power approximately 26 million U.S. households.
Based on the DoE's lifecycle assessment, an incandescent bulb, over its useful life burns 350x the amount of energy required to produce it. For LEDs, the number is 40 today, and is expected to drop to 28 in the next five years.
Much of the installations to date have been in commercial and public buildings rather than homes. Point of fact, the Mona Lisa
is currently being lit by LEDs, part of a multiyear lighting contract that Toshiba has with the Louvre.
Still, according Reuters
, even though LEDs are eight times more efficient than conventional incandescent bulbs, they are still ten times more expensive.
Global consultant McKinsey estimates that an LED bought for home use in 2011 will take until 2025 to pay off. Lighting companies are trying to cut LED prices by a number of methods, including using silicon instead of sapphire and rare earths and using electronics to compensate for the resulting difference in performance.
In order to help achieve the desired level of penetration in homes as well as businesses, last week the DoE announced
$10.1 million in funding for five companies working on efforts to further improve LED efficiency while bringing down their cost to make them even more attractive to consumers today. All of these awards involve matching funds from the recipient companies.
This funding round exceeds last year's $7 million
, which came in the midst of efforts on the part of conservative lawmakers to roll back new standards for lighting efficiency.
In fact, one company, Cree Inc.
of Durham, N.C. received funding in both rounds. Last year the company was awarded $2.344 million to improve and cost-reduce its existing technology, which relies on fewer raw materials. This year, Cree will receive an additional $2.3 million to develop a modular design, encompassing electrical, mechanical, and optical elements to enable modules to be linked together to illuminate areas of almost any size. This will help reduce assembly cost and ensure strong performance.
Cree's LED bulbs
, available at Home Depot for under $10, can pay for themselves in a year or less, depending on the application and local electric rates. Cree, which is the parent company of Ruud Lighting in Sturtevant, Wisc., also makes a direct LED replacement for linear fluorescent tubes
that are commonly used in many commercial and industrial applications. Cree's project in North Carolina will create a scalable light module for low-cost, high-efficiency LED luminaires.
Phillips is working a method of manufacturing its Lumiled LEDs that won't require the costly removal of the sapphire substrate. Credit: Phillips.
. received $2.4 million to streamline its LED manufacturing process with an eye towards reducing cost. The-Cleveland-based company will develop a new light fixture design fixture design that allows the LED chip to sit directly on the heat sink, eliminating unnecessary parts and thereby improving heat transfer within the fixture while increasing LED efficiency. The research will take place at Eaton's Menomonee Falls, Wisc. plant. According to Kathleen Hogan
, who heads the DoE's energy efficiency program, "If heat builds up around the bulb, it can interfere with the efficiency, so one of the things you want to do is build the bulb so that heat can be shepherded away from the lamp itself."
When Eastman Kodak decided to get out of the business of producing organic LEDs (OLEDs), a technology that originated in their labs, they let go of 50 of the world's top experts in the field. A number of them decided to get together and form OLEDWorks to continue the development of this technology.
OLED is a solid-state lighting (SSL) technology composed of thin organic layers sandwiched between two electrodes. They are typically assembled through transfer or screen printing. When DC current is applied, electroluminescence
occurs and visible light is emitted. OLEDs are configured as two-dimensional panels that glow. This creates uniform areas of low-energy soft emission rather than the point sources we are accustomed to using today. OLEDWorks received $1 million from DoE to "develop and demonstrate new spray printing equipment that reduces overall manufacturing costs and could help support cost-competitive mass production. This technique will give manufacturers greater spray control to take full advantage of expensive organic materials and maximize the visible light produced from this material."
Also funded in this round was Phillips, which makes "the brighter LEDs" known as Lumileds
. Phillips is taking a different approach to reducing the cost of LEDs. Most LEDs are grown on a sapphire substrate that must be carefully etched off the device before light can shine through it. DOE has awarded $1.8 million to Phillips to "develop an alternative to the standard flip-chip device that grows an LED face-down on the sapphire substrate. The Philips Lumileds device will treat the sapphire substrate so that removing the substrate is not necessary-reducing manufacturing costs without compromising lighting quality."
Finally, Pittsburgh Paint and Glass, also known as PPG
, received $2.3 million to develop a cost-effective manufacturing process to help commercialize an integrated substrate that includes the glass foundation as well as the other necessary layers for OLEDs. The project will also use standard-grade glass, lowering costs while maintaining performance. Commercially-available and low-cost integrated substrates will help build a reliable, high-quality supply chain for this emerging industry. OLEDs have the potential to produce four times as much light per watt as incandescent bulbs.
DOE expects this round of funding, its fourth overall, "to accelerate domestic manufacturing and technical leadership in energy-efficient technologies, helping to create jobs, boost exports, and strengthen America's role as a global leader in the clean energy race."