Remove or reduce unnecessary lighting

Why

Lighting not only is a significant part of your electricity consumption, it adds to your base demand, costing you more on your electricity bill.

How

Start in areas that you know are over lit, or in spaces where people are not doing detailed work – such as hallways and lunchrooms.  If you have multiple-tube fluorescent fixtures, disconnect one or two tubes,  or replace tubes or bulbs with lower wattage ones.  Do this outside work hours, and don’t announce it.  Our eyes notice a change if we see it happen, but as long as light levels are appropriate for our tasks, we are not likely to notice the new light levels when we enter a space.
Alternately, you can hire a lighting designer to assess the light levels throughout your space.  You may find that some spaces are under lit, and you need to add brightness.
As we age, we need more light.  A 60 year old needs three times the light to do a given task that a 20 year old needs.  Make sure you have suitable light levels for your employees.