Great question! You will find a few things on Google and the from the block-stores, however you will need a knowledgeable electrician to make it all happen correctly.
- With a large project such as yours I would demo one floor first!
- Check with a local electrician and wholesale electrical supply store that only sells to contractors.
- I use City Electric in Florida and they are great at re-searching what type of motion configurations options I may need.
With that type of energy bill, you could also check with your local power company and schedule a commercial energy audit/ survey. California has some very nice incentives from the power companies to reduce kWh and demand. I highly recommend you complete this step first before spending any money!
Some other ideas:
- Reduce the wattage at each fixture by changing the bulbs to LED
- Motion sensors will work--- however you will need them at the entry and exit of each hallway. They will be wired into the line side of the circuit to control the lighting load (20 lights).
My favorite which lasts a long time is a timer.
- Locate the breaker/ circuit that controls each floor hallway lighting and put it on a timer for a majority of the lights.
- You could leave two lights or more on 24/7 for safety in the middle of the hallway if the indirect lighting is not enough.
For more information:
Read "Would hallway lighting that uses motion sensors reduce costs in a 288 unit coop?" a Q&A answered by David Bergman.