In my building there are 18 rows and each row has 21 (6+8+1+6) fluorescence tubes in doublet (i.e., 42 in numbers) for lighting. All the tubes are covered with screen and therefore total 756 tubes are used everyday for lighting. The cover reduce the intensity of light, therefore, if we remove the cover it will increase the intensity of light and then reduce the number of tubes to be used. By this way, we can convert the doublet into singlet and the number will be half = 378 tubes.
We can also reduce some tube in between that and it will not reduce the intensity. There is symmetric pattern of distribution of tube and it cause same number of tubes in the area where no-one works like instrument or freezer area. There we can put less or 1-2 tube. I feel it will bring the number of tubes used to 300-310.
Again each sitting table and working bench does not need such tube, but there is tube and people use, which is unnecessary wastage of electricity. We should remove these. I have not added these numbers in above calculation. There will be no affect on work because I never used this.
People should remove the curtain from the window in daytime while they work. It will allow the sunlight to come inside. There is no need to open window.
It is good to advise people to switch of the light whenever it does not require and before leaving but we cannot force them. It will be better to keep someone to switch off light whenever there is no one present in both day or night times. The expenditure on the salary of such person will be far less than our saving.
Use of new compact fluorescence tube will also save energy consumption.
I am not calculating how much energy it will save by doing mathematics but whatever it is, it is good to save energy.