As mentioned in a recent article, we have had a couple of surveys conducted on the site, and both immediately singled out lighting as an area where we can cut our expenditure / consumption. This is an obvious place to look really as we are a large warehouse with a lot of lights.
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.
- We have over 500 tubes of varying sizes on site.
- If a room lit by fluorescent tubes is unoccupied for more than 9 minutes it is more energy efficient to turn the light off.
- 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.
- 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.
- These sensors are in an unsuitable place, and in failing to control the lighting acceptably they have been covered up.
- There are no light switches for these warehouses; the lights are on all day, every day.
- 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.