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PACIFIC GAS & ELECTRIC has been investigating the
advantages of utilizing emerging technologies, and performing an
analysis of their associated energy savings. Upon being
approached by Kaiser Permanente & Petaluma Valley Hospital for
the installations of operating room LED (Light Emitting Diode)
lighting fixtures a study was commissioned to determine the true
savings of this application, and the associated economic benefits.
The LED’s would replace their existing halogen surgical lights in the
hospitals’ operating rooms. This study captured both the direct
savings from the lower electrical demand equipment and the
indirect savings from the associated HVAC loads.
THE PROPOSED LED surgical lights would consume 54% of the
energy required by halogens. Other significant benefits of the LED
fixtures are an adjustable beam temperature (i.e. color), they are
not subject to immediate burn out and the bulbs have a longer
useful life.
Executive Summary
ADDITIONAL ENERGY BENEFITS to the direct power reduction for the LED lighting is in the reduced HVAC load for the
associated hospital’s equipment. However, because of the way each of the hospital’s HVAC systems is currently controlled, the
controls would require a minor setpoint adjustment to realize these additional savings. The HVAC system in both facilities is a
constant volume system with reheat, which has constant supply air temperature setpoints. With the removal of the lighting’s heat
load the reheat will increase in gas load of 1 therm/10 kWh of direct savings in lighting, unless the supply air temperature setpoint is
raised to compensate for the reduced heat from the light fixture. By changing their associated setpoints the available indirect
energy savings can be realized. The associated savings are 1 therm in gas and 17 kWh in HVAC savings for every 24 kWh of direct
lighting savings.
OPERATING ROOM LED FIXTURES have high first costs: $20,000 for each Halogen fixture and $27,000 for each LED fixture and
have a lifespan of 15 years (for the fixtures). Because of the high cost of the fixture, the benefits associated with replacement based
on just energy savings are not economically viable. However, if a replacement is performed there are real savings. LED
Replacement savings are summarized as follows for Kaiser’s 12 Operating rooms, which are proportional to Petaluma:
Table E1 – Savings Summary Per Year – Total of 12 OR LED replacement
Figure E-1: Kaiser Operating Room & OR Lights
Figure E-1: Kaiser Cardiac Operating Room with Halogen OR Lights
No Control Changes Modify AHU Setpoint
Direct Indirect Total Direct Indirect Total
kWh 11,673 0 11,673 11,673 8,070 19,743
Therms 0 -1,248 -1,248 0 481 481
$ $1,051 -$998 $52 $1,051 $1,111 $2,161
PG&E Incentive $584 $0 $584 $584 $0 $584
Payback (Early Retirement, Avg.) 308 6,185 150
Payback (Incremental) 79 1,595 39
*This model is conservative because other areas would also have savings due to less reheat. PG&E does not pay an incentive for indirect savings.
Salas O’Brien Engineers | expect a difference | Project No. 09104
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