For 755 troffers in a new IT office space, MGM Resorts evaluated three lamp options:
■ A code–mandated minimum of 2x4 linear, 30,000-hour fluorescent T8 lamps (96 watts)
■ Extended-life, 75,000-hour, 2x4 linear fluorescent T8 lamps (84 watts)
■ 2x2 LED, 50,000-hour lamp fixtures (44 watts)
Both fluorescent options assumed three lamps per fixture, while the LED option had one module.
Each lamp option was evaluated with and without controls. The additional installation cost for controls with each lamp option was roughly $47. The analysis assumed that occupancy controls would decrease consumption for the two fluorescent lamp options by 30%. For the LED option, a roughly 42% usage decrease for controls was projected due to dimming and daylight dimming capabilities as well as occupancy sensors.
The 10-year cost of ownership was projected for each system (see table below). For the 30,000-hour fluorescent option, the projection included the cost of one lamp replacement.
MGM ultimately chose the LED upgrade with full dimming controls. The breakdown of cost and benefits over the baseline option included:
■ $165,000 lighting spend ($69,000 incremental)
■ 68% energy reduction totaling 125,000 kWh saved annually
■ 33.9% ROI