Calculated energy savings

I want to know – how much money would I save if I turned off my lights in my office, every time I left?  This is a fairly simple calculation.

First – let’s figure out how much it cost for electricity in my office space:

4 fixtures x 3 lamps x 32 watts per lamp / 1000 watts per kilowatt = .384 kw

hours of operation – 8am – 5pm (9 hours) x 260 days per year [for the calculation I am ignoring my vacations] = 2340 hours/year

cost of operation – .384 kw x 2340  hours/year x $0.08/kwh – $71.88

The cost to operate the lighting is much higher that I would have thought.

Now – let’s calculate how much I can save by turning the lights off when I leave my office space:

4 fixtures x 3 lamps x 32 watts per lamp / 1000 watts per kilowatt = .384 kw

hours I am typically out of my office – about 3 hours per day x 260 days per year [for the calculation I am ignoring my vacations] = 780 hours/year

savings – .384 kw x 780  hours/year x $0.08/kwh – $23.96

The savings is also much higher than I thought.

Now this assumes that I turn my lights off every night when I leave work and over the weekend (which I do). But what if I didn’t:

So now – let’s figure out how much it would cost for electricity in my office space:

4 fixtures x 3 lamps x 32 watts per lamp / 1000 watts per kilowatt = .384 kw

hours of operation – 24 hours per day x 365 days per year  = 8760 hours/year

cost of operation – .384 kw x 8760  hours/year x $0.08/kwh – $269.11

The cost for leaving the lights on all day and night is significantly larger than if I turn them off at night.

So what would the total savings be if I switched to turning the lights off:

4 fixtures x 3 lamps x 32 watts per lamp / 1000 watts per kilowatt = .384 kw

hours I would have the lights on – about 6 hours per day x 260 days per year [still ignoring my vacations] = 1560 hours/year

cost for lighting- .384 kw x 1560  hours/year x $0.08/kwh – $47.92

Total potential savings – $269.11 – $47.92 =$221.19

Now that is a huge savings.

So what is the moral of the story?  Don’t discount minor changes you can make to save money. In the case where someone leaves their lights on and then chooses to turn them off, there is a huge impact. Try this simple calculation for your space – at work or at home.

Related articles

• Hot Tips on How to Save Energy On Indoor Lighting (energyguard.wordpress.com)
• How much does it cost to run a 5 watt bulb (wiki.answers.com)