Lighting by Example
Lighting by Example
Governments are among the largest single energy users in their countries. The sheer volume of their purchasing means that a purchasing policy emphasizing efficient products would have a great influence on national aggregate energy use.
However, equally important is their ability to lead by examle.
This article examine the United States, which spends $10-20 billion per year on energy-using equipment.
Governments often encourage the citizenry to save energy. But, do they practice what they preach? Given the sheer size of governments, in terms of numbers of buildings and the energy-using devices in them, their potential to create market demand for new technologies and save energy by focusing on their own operations is immense. In some cases, governments are the largest single users of energy in their countries! This article presents the case study concerning the United States, which spends a whopping $10-20 billion per year on energy-using equipment, plus an additional $4 billion per year on energy in the non-defense sector. Lighting is an important piece of the puzzle.
Most efforts by the US Federal government to save energy can be traced back to the Energy Policy Act (EPACT) of 1992, which encouraged a host of activities. This was followed by a 1994 Presidential Executive Order No. 12902 requiring that Federal facilities reduce their energy use by 30% (on a square foot basis) by the year 2005.
Identifying Best Practices
FEMP:s Luminaire cost-effectiveness example
An overarching part of the Federal Energy Management Program (FEMP) initiative is to specify performance targets. Rating specific lighting products and components has been relatively easy. Specific recommendations exist for Exit signs, fluorescent lamps, and fluorescent ballasts. In the case of Exit signs, there was a pre-existing Energy Star criterion which FEMP could adopt.
In the case of fluorescent luminaires, the problem is more challenging. Desired performance levels were defined using the Luminaire Efficacy Rating (LER) (See IAEEL Newsletter 1/94). The LER was developed in response to a particular EPACT objective for launching a public sector in-house information program on luminaire energy performance. To our knowledge, FEMP is the first entity to formally incorporate the LER into procurement guidelines.
The LER describes the efficacy of the entire luminaire, per guidelines set out by National Electrical Manufacturers Association (NEMA) Standard LE-5, in terms of rated lumens of total light output per watt of input power. The LER is thus very specific to a given luminaire since it incorporates the individual and combined effects of lamps, ballasts, and fixture optics. FEMP stresses that a good LER is not the whole story. Good lighting design and controls are also essential elements of a truly efficient solution.
The LER is not without its weaknesses: When visual tasks are considered, it becomes clear that all luminaires are not created equal. Where VDT tasks are concerned, for example, the imperative to ensure visual comfort can require some trade-off in terms of luminaire efficacy. For purposes of the Federal purchasing program, the LER targets are stipulated according to fixture type. The LER would be further improved if it were to accommodate other metrics of lighting quality.
Similar efforts are considered in Europe; for instance, a labelling system based on methods similar to the US LER system have been discussed. However, there is still no consensus on how a rating system should accommodate various lighting quality criteria and the complexity of different lighting applications.
Purchasing Power
The aforementioned Executive Order also called explicitly for Federal agencies to limit their purchasing choices to the most efficient products available (i.e. within the top 25%). To support these goals, FEMP issues a range of product efficiency recommendations. Recognizing that identifying efficient products isnÕt in itself a complete solution, the recommendations also
- identify Federal supply sources that offer efficient products.
- suggest ways for buyers to identify efficient products when purchasing from commercial sources.
- present a cost-effectiveness example in order to help buyers judge whether a price premium is really Óworth itÓ.
- offer tips to help buyers and users save energy without sacrificing comfort or performance.
- provide leads to other useful sources of information on product energy efficiency.
In their capacity as Federal supply agencies, the General Services Administration (GSA) and Defense Logistics Agency (DLA) work with FEMP to clearly identify supplied products meeting the recommended efficiency levels. In their catalogs and on-line systems, GSA and DLA use an ÓEE symbolÓ or the Energy Star label to identify those products that meet or exceed the energy efficiency criteria for government purchasing.
One early sign of success is that the two largest construction agencies within the Federal government (Army Corps and Navy) have incorporated the recommended efficiency levels for some products, including lighting, in their design guidelines.
Tools & Training
Examples of recommended efficiency levels for federal purchasing (USA FEMP)
FEMP also recognizes that evaluating efficient lighting opportunities can be complicated. Software tools are offered to energy managers to help them evaluate the economic and technical performance of efficient lighting solutions. FEMP offers eight software tools, including the Federal Lighting Expert (FLEX). These can be downloaded directly from the FEMP web site.
Training is essential to the successful implementation of energy savings, and lighting is no exception. FEMP addresses this through an extensive educational offering for energy managers. Taking advantage of the new generation of on-line "distance learning" courses, students can proceed at their own pace, using the Internet to communicate with instructors and fellow classmates in a virtual classroom. The course covers fundamentals, measurements, technology, economics, applications, audits, and implementation issues.
Test Beds for New Technology
New technologies are always in the pipeline. Here again, governments can lead by example when it comes to demonstrating the merits of newly emerging technologies. Perhaps the most prominent example of this in the US was the demonstration of the then-new sulfur lamp technology and light-guide systems by the US Department of Energy (See IAEEL Newsletter 4/94). Although the technology has thus far failed to take off in the market, the demonstration project has provided very useful experience.
Another example focuses on advanced lighting controls for office environments. In this project an advanced control system was installed at the San Francisco Federal Building, governing over 800 fixtures in 174 controllable zones throughout an occupied area of 18 000 square meters. Data are being collected from nearly 200 meters. A range of control strategies Ñ representing products from eight different manufactures Ñ were implemented and are being evaluated. Early results indicate that energy demand has been reduced by 25 percent, saving $450 000 per year (lighting and non-lighting end-uses combined).
The US Post Office, in collaboration with Lawrence Berkeley National LaboratoryÕs FEMP-support program, has recently developed a new lighting system for mail-sorting workstations. The design, currently being tested as a prototype at one post office, includes modified task and ambient lighting systems plus lighting controls. Worker visual comfort is a key determinant of mail-sorting error rates. The new design reduces energy use as well as glare. If test results are positive, the system may be adopted nationwide.
Although we focused on examples in the United States, government energy management programs exist in numerous countries. Many of them have recognized that lighting is a good place to start. Although a number of countries, including the Netherlands, Denmark, Finland, and Sweden, have implemented extensive demonstration programs, they have yet to combine these efforts with an extensive procurement program like the the US FEMP program.
Evan Mills
References:
- FEMP Procurement website
http://www.eren.doe.gov/femp/procurement/ - NEMAÕs Procedure for Determining Luminaire Efficacy Ratings for Fluorescent Luminares, LE5-1993. http://www.nema.org
- Advanced Lighting Controls Demo
http://eande.lbl.gov/CBS/femp/450GG/450gg.htmlFEMP Contact Info:
Katie Kroehle McGervey, Program Manager
Office of Federal Energy Management Programs
U.S. Department of Energy, EE-90
1000 Independence Ave., SW
Washington, DC 20585-0121
Tel: +1 202 586 4858, Fax: +1 202 586 3000
Email: Katie.McGervey@hq.doe.govFor information on government energy management programs in other countries, see Borg. N, Mills, E., Martin, N., and Harris J. 1998. "Energy Management in the Government Sector: An International Review" Lawrence Berkeley National Laboratory Report No. LBNL-40403. Berkeley, CA. Also in Proceedings of the 1997 ECEEE Summer Study, Prague, Czech Republic Panel 4, ID 150, pp. 1-24. European Council for an Energy-Efficient Economy (Copenhagen). Available at www.eceee.org
For a paper on a proposed luminaire rating system for Europe, see Axel Stockmar, Proposal for a Luminaire Specific Index for the Description of Photometric Properties of Interior Luminaires Taking into Account the Efficient Use of Energy, on www.iaeel.org, Right Light 4 Proceedings.