Which of the following is NOT used to calculate energy savings?

To determine energy savings, it is essential to calculate the various components associated with energy consumption and cost. Fixture wattage is crucial as it indicates how much energy the lighting system consumes; operating hours are necessary to understand how long the fixtures are in use and therefore how much energy they consume over time. The electricity rate is significant because it tells you the cost of that energy, which is integral in calculating total savings.

Lamp life, while important for understanding replacement schedules and overall system longevity, does not directly factor into the calculation of energy savings. It pertains more to maintenance and operational costs rather than the immediate consumption of electricity or its associated costs. Thus, lamp life does not influence the energy savings calculation itself.

Therefore, the choice that does not serve a role in calculating energy savings is lamp life.