As a brief intro, we essentially have 5 warehouse areas built over the last 20 years or so, of different heights, lit by fluorescent tubes for 24 hours a day, 7 days a week; such is our working pattern.  In addition, we have a few office areas that are, in the main, occupied only during office hours. 

Whilst I will admit there is plenty we can do to cut our lighting bill, I think those auditing the site are under the impression that it is a bigger problem than the data actually suggests. The Carbon Trust report estimated that lighting accounted for 27% of our electricity consumption, and this is what I have discovered to date.

1. We have over 500 tubes of varying sizes on site.
2. If a room lit by fluorescent tubes is unoccupied for more than 9 minutes it is more energy efficient to turn the light off.
3. Getting people into the habit of turning off lights when leaving a room is difficult, but not impossible – I deem this a work in progress.
4. Two of our warehouses which were built in the last 10 years were fitted with daylight sensors – these warehouses have higher roofs and are generally lighter.
5. These sensors are in an unsuitable place, and in failing to control the lighting acceptably they have been covered up.
6. There are no light switches for these warehouses; the lights are on all day, every day.
7. Indoor lighting is responsible for approximately 11% of our consumption, with outdoor lighting on a sensor and adding about another 0.5-1%.

As stated at the beginning, there are measures we can take, but at only 11% of consumption, they will have a limited effect. I will update you with the results of these efforts at reducing our lighting bill in a later post.