It is official. The Department of Energy’s latest report, Energy Savings Potential of Solid-State Lighting in General Illumination Applications 2010 to 2030, codifies the savings potential of solid-state lighting over the next 20 years. With massive amounts information and graphs enough to satisfy the most data-hungry lighting insider, the report is further validation of the direction the LED industry is taking. The rigor and deep analysis should be applauded.
The industry has known that solid-state lighting – or LEDs to the rest of us – will have a profound impact on the lighting market. Vendors have been readying products for all applications, striving to improve raw LED output, maximizing, and matching the fixture design to the application. And the work is set to pay off as LEDs move into mainstream lighting; ready to bring a surge of energy savings along with them.
What is remarkable, and what the report does an excellent job of showing, is the mind-boggling impact that LEDs will have on the country’s lighting-related energy use (see chart on p. 34, Figure 7-4. National Energy Consumption for Lighting through 2030 for Each Scenario). Even this incredible impact may be conservative given two other characteristics of LED lighting, besides raw efficiency, that will amp the savings up even further:
- The first is the directionality of LEDs. Traditional lighting sources shoot light everywhere and it is the job of reflectors and optics to attempt to rein the light in. LEDs are very directional and well-designed fixtures can put the light exactly where you need. We have found that users can see equivalent light from an LED fixture (measured in foot-candles) for one half to one quarter of the lumens from a traditional fixture. The report mentions the possibility of savings from directionality, but takes a wait-and-see approach before baking it into the savings numbers. Our work suggests that directionality can account for a 10% to 25% additional savings.
- The second is the controllability of LEDs. LEDs are a semi-conductor technology that is amenable to being controlled digitally by computer technology. And this control can be implemented with no loss in performance measured in either light level or lifetime. This is in direct contrast to traditional lighting technologies that are infamously hard and expensive to control. Our work, as well as the work of others, shows that using light only when you need it can reduce energy use by another 25% to 50%.
The DOE’s report does a great job of laying out the impact that LED will have on the world. But, I believe there is another 50% more savings still available for the nation.