FEMP:s Luminaire cost-effectiveness example
Performance	Base model	Recommended level	Best available
Luminaire efficacy rating (LER)	32	62	73
Luminaire light output	3 600 lumens	3 700 lumens	4 150 lumens
Power input	113 W	60 W	57 W
Annual energy use	407 kWh	216 kWh	205 kWh
Annual energy cost	$24	$13	$12
Lifetime energy cost	$240	$130	$120
Lifetime energy cost savings	-	$110	$120

Cost-effectiveness assumptions:

• Lifetime energy cost is the sum of the discounted value of annual energy costs based on average usage and an assumed luminaire life of 15 years. Future electricity price trends and a discount rate of 4.1% are based on federal guidelines (effective from April, 1998 to March, 1999).
• This example shows the cost effectiveness of energy-efficient 2'x4' recessed, lensed luminaires. The Base Model uses three 34 watt T12 lamps, while the Recommended and Best Available models, despite providing greater light output (lumens), use only two 32 watt T8s.
• Usage assumption: 3 600 operating hours per year.
• Three sets of lamps would be used over the assumed luminaire lifespan of 15 years.
• Assumed electricity price: $0.06/kWh, the 1996 federal average electricity price in the US.