For example, say you have a 1 million sqft distribution center that has 2,500 metal halides(1000w) and operates 80 hours a week. Thats about 11,440,000 kilowatts per year. Lets say the the utility rate is .15 a kwh. That comes to about $1,738,000 a year in lighting cost. If you were to retrofit them to a 6 lamp T5HO Hibay fixture(360w), your kilowatts per year would be about 4,433,000 x .15 kwh comes to a total of $540,000 a year in lighting cost. A savings of about $1,300,000 million a year.
The difference is like night and day. Not only will most states pay you to do this type of lighting retrofit, you will end up seeing a pay back in less than a year and in some cases less than 6 months. Take a look at the chart below to see how the savings add up.