DOE studies estimate savings potential of LEDs
According to the studies, energy savings to date from LEDs exceed the power produced from one large electric power plant — more than 8 billion kW-hours. If solid-state lighting achieves its price and performance targets over the next two decades, this will remove the need for more than 30 percent of the estimated lighting energy consumption. In turn, this will represent billions of dollars of savings for consumers.
The studies were released to coincide with the DOE’s workshop on Solid State Lighting, which was held in Washington, DC on November 13-14. Through the Building Technologies Program of the Office of Energy Efficiency and Renewable Energy, the DOE has launched a solid-state lighting (SSL) R&D program that encompasses both core technology research and industrial product development.
The DOE has set aggressive goals for the SSL program; by 2015, it plans to develop advanced SSL technologies that, compared with conventional lighting technologies, are much more energy efficient, longer lasting and cost competitive. DOE is targeting a product system efficiency of 50 percent with lighting that accurately reproduces the full spectrum of sunlight.
A number of projects have already been funded, and DOE hopes to secure a budget of $7.75 million for the current financial year. Further, it is hoped that the Energy Bill currently making its way through the US legislature will provide strong backing for SSL, which will in turn result in substantial increases in funding for SSL in future years. The studies are intended to justify the need for this funding.
Niche applications
The study titled “Energy Savings Estimate of Light Emitting Diodes in Niche Lighting Applications” finds that LED traffic signals use only 10 percent of the electricity consumed by the incandescent lamps they replace. In other words, 90 percent of the electricity bill that municipalities pay can be eliminated. Moreover, LED signals last several times longer, allowing for additional savings through reduced maintenance costs.
Exit signs are identified as another important niche application, where an estimated 80 percent of the US installed base of exit signs now use LEDs.
LEDs have also made inroads into mobile applications such as brake and signal lights on trucks, buses and automobiles. In the report, the energy savings of these applications are reported in gallons of gasoline and diesel fuel because the electricity is generated on-board. To date, 41 million gallons of gasoline and 142 million gallons of diesel fuel are saved annually because of LED use on these vehicles.
If the entire fleet of automobiles, trucks and buses were to convert to LED lighting, 1.4 billion gallons of gasoline and 1.1 billion gallons of diesel fuel could be saved each year. In gasoline, that is the energy equivalent of 30 days of oil flow in the Alaskan pipeline at full capacity; and, in diesel, that represents 12 days of national consumption.
General illumination
The study titled “Energy Savings Potential of Solid State Lighting in General Illumination Applications” estimates the energy savings potential if solid-state lighting can achieve certain price and performance criteria.
The report considered two scenarios – one where the technology receives a moderate national investment of $50 million per year and an accelerated scenario based on an investment of $100 million per year. Solid state lighting achieves different cost, efficiency and durability targets under each scenario.
Under the moderate investment scenario, in 2025 the energy saving associated with solid-state lighting will total approximately 114 billion kW-hours, or the equivalent electrical output of about 14 large power plants.
Under the accelerated investment scenario, in 2025 the total energy saving is nearly three times higher – reaching 326 billion kW-hours, representing more than 40 large power plants. Over the analysis period of 2005 to 2025, the cumulative energy savings under the accelerated investment scenario total nearly 1,850 billion kW-hours, which equates to more than $120 billion in electricity bill savings for the United States over that time period.
