Up to 25% of energy use in labs is attributable to lighting; a higher percentage than lighting uses in the typical office setting. This is due to both the type of work that is carried out in laboratories and the additional hours laboratories are occupied each week1. Decreasing demand for power by decreasing lighting demand in laboratories can go a long way in reaching our overall goal of a 15 percent reduction (or more) in power usage. Some suggestions for curbing our energy usage related to lighting are discussed below.
Have you heard the myth that it uses more energy to turn a light on and off frequently than to just leave it on? MythBusters set out to bust this myth and were successful! Turning off lights is the way to save energy, even if the room is unoccupied only for a few minutes. Click Here to get Mythbusters' details on how "lights off" trumps "leave lights on".
Decreasing lighting levels by turning off unneeded lights during summer afternoons is especially important, when the demand for electricity is at its peak. Turning off lights and utilizing day-lighting strategies can reduce energy demand by up to 50 percent during these times2.
In fact, daylighting is the most efficient light source for labs. Daylighting provides the most light for the amount of heat gain occurring in the lab (see figure below)1. Excess heat from artificial lighting has to be counteracted by air conditioning (which increases energy demand)1, so increasing the use of daylight is a smart and energy-efficient way to illuminate research areas.
Other energy reduction strategies for lighting in labs include:
--switching to Compact Fluorescent Light (CFL) bulbs wherever possible. Energy Star-rated CFLs use 75% less energy than normal light bulbs and last up to 10 times longer3. There are many different kinds of CFLs available, and Vanderbilt has a CFL Recycling Program for the bulbs that (eventually) burn out.
--turning off task and desk lights when they are not in use.
--reducing or eliminating the use of halogen floor lamps. Halogen floor lamps can be dangerous because they operate at very high temperatures; they also use two to three times the energy of a traditional fluorescent bulb4.
If Vanderbilt decreases its lighting demand by 15%, it would avoid consuming almost two megawatt-hours of electricity in a day!
But what does this mean?
Two megawatt-hours of electricity is the same amount of power consumed by 46 average-sized homes in Nashville in a day. That's a lot of juice, Commodore Fans.
Check The Math
22% of power for lighting x 60 megawatt-hour consumption per day = 13.2 megawatts
15% of 13.2 megawatt-hours = 1.98 megawatt-hours
Energy consumption of one average house in Nashville for a day = 0.043 megawatt-hours5
1U.S. Environmental Protection Agency (USEPA) Labs21 Program, “Efficient Electric Lighting in Laboratories”, August 2006
2 Energy Center of Wisconsin, “Energy Savings from Daylighting: A Controlled Experiment”, Report No. 233-1, May 2008.
3 Energy Star™ web page “Compact Fluorescent Light Bulbs”, 2008 .
4 California Energy Commission web page “Lighting Efficiency Information”, 07/01/08.
5 Nashville Electric Service web page “Residential Rates”, 2008.