Swapping out light fixtures and types has been an easy choice for most older facilities looking for energy efficiency increases. This often benefits office spaces and similar facilities greatly, as light sources use the second or third most energy in a typical building. For a data center, because of the amount of energy used for the IT equipment, the amount of energy used for lighting is often an afterthought. However, with today’s lighting technology (such as LEDs) and the need to save every kWh, the lighting systems should be among the most efficient on the market. Occupancy sensors and timers should be added to the data center spaces to turn off lights when not needed to save energy. Depending on the sophistication of the data center, lighting controls can also be added to the rest of the facility while still meeting minimal security needs. The payback for these extras might seem long when compared to other systems, updates or advancement, but the ability to visually demonstrate how you are able to lower energy waste is an added benefit. Also a lower PUE, even if only marginal, is a bonus for the entire facility.