You probably already have the most efficient lighting....
http://en.wikipedia.org/wiki/Luminous_efficacy
Back in April, I reported about some data that showed lighting efficiency projects are proving to be some of the best green technology investments that a facilities manager can make. But how much money will the investment ultimately save your organization? One of the “intelligent” lighting technology providers, Digital Lumens, has created an Energy Savings Calculator to help shed a little more light on the equation.
Like most of the energy efficiency calculators that have been created over the past several years (notably the ones focused on carbon footprint metrics), this is a rather simple engine. The sorts of data you submit include type and number of fixtures at the location, the square footage, the zip code (for the electricity rates), and operating hours.
The results are a five-year analysis for three different scenarios. What you are using now, simple LED retrofits, an LED retrofit that is connected via an intelligent network for tighter controls. You can also test the impact of an expansion or a rate increase.
