Computers: Notebooks are very different from desktops.
Air conditioning: according to the power, but also related to the month of opening, the time of opening every day and the adjusted temperature.
If you sometimes switch to electric fans in summer, you will also save a lot.
Light box: this also depends on the power of the light, but it can be large or small.
There are also drinking fountains, audio equipment and so on.
This can only be calculated by considering specific aspects, I think.