In a recent Plant Engineering column, David R. Laybourn of Lime Energy discusses how a lighting retrofit for a company with multiple manufacturing plants works.
Laybourn writes that the first step of a project is to conduct lighting audits of each building, which act as blueprints in the redesign process. The audit includes data on the existing lighting fixture type, lamp and ballast from every room in each building. The audit also identifies opportunities to turn off lights.
Then the audit is turned into a formal proposal where alternate fixtures are identified and installation costs are prepared. The proposal should include detailed calculations of energy savings projected from the new fixtures based on reduced energy use, fewer operating hours, or both.
Laybourn says motion sensors and photocells are good for controlling lighting. This strategy helps to keep lights off when they are not needed and can add to energy savings and result in more reduction in CO2 emissions.
The savings can be large. Laybourn writes that recent lighting retrofits for eight plants belonging to a global food products company are projected to save nearly 4 million kilowatt hours annually and reduce CO2 emissions by more than 5.4 million pounds each year. At the time of the audits and proposal, savings were estimated to be around $400,000 annually.