Costs of Lighting

Last summer, our group wired a downtown Hamilton office building with the new technology. We hoped to save the company 50 per cent on its energy bill. This estimate was based on experimental studies we conducted. The actual saving was 78 per cent.

Here is an example to demonstrate the cost of operating fluorescent fixtures - with and without the use of our dimmer. A typical fluorescent lamp fixture uses 80 W (Watts) of electrical power and provides lighting for 100 ft² or 9.29 m².

The energy required for continuous operation for 1 day is (80 x 24) 1920 Watt-Hours or 1.92 kWH. The corresponding cost (at 8.5 ¢/kWH) is 16.32 Cents or $ 0.1632 (per day).

For one fixture the cost for a full year, lights always on (no dimming) is $59.57
but with managed levels (using dim&save):
--- 254 days with 11 hours at 60% level = $11.40 (daylight harvesting)
--- 254 days with 13 hours at 32% level = $ 7.19 (maintenance level)
--- 111 days with 24 hours at 32% level = $ 5.81 (maintenance level)
--- the total cost is $24.40 per fixture, saving is $35.17 or 59%

For a building with 12 floors, each with 10,000 ft² and 1200 fluorescent lighting fixtures:
---The lighting cost with no dimming is $71,484 annually.
---The lighting cost with dim&save is $29,280 annually.
---The saving of 59% corresponds to $42,204 annually.