4 - 40 watt bulbs = 160 watts per hour

160 watts per hour x 24 hours = 3,840 watt hours

3,840 watt hours divided by 1000 = 3.84 Kwh per day (1000 watts = 1 Kwh)

3.84 Kwh x 30 days (1 month) = 115.2 Kwh per month

115.2 Kwh x $0.06050443 hydro rate = $6.96 per month

So by going with this math (I hope it is correct)I am spending an extra $6.96 per month on my hydro by just leaving the lights on in my garage. If I did turn them on and off just when I need them do you think it would cost me more or less than what I am spending now, and how much more wear and tear am I causing the electrical components of the lights ? If anybody has any ideas about this I would love to hear them, also if my math is wrong please tell me the proper formula I would need to figure this out, I have always wondered about this and I am just trying to figure it out. I have asked people at work about it and they are pretty evenly split as to weather I should leave them on or off, so I am now turning to all the smart people here on M&M to set the record straight. I am looking forward to hearing all of your responses.

You are right about the ballast drawing more power at startup than when it is "warmed up".

I would have to do a lot of math to find the difference. It would be dependant alot on how many times you switch them on/off.

I have four - 2 bulb flourescent fixtures(4ft) in my garage, all 40W bulbs, and one single bulb fixture(4ft,25W) over my workbench. There isn't very much difference in how bright they are between 25W and 40W and if you get the right "color temperature" bulbs, you probably couldn't tell the difference.

What I'm getting at here is, a lot of those fixtures will run either wattage bulb and 25W would cost less to run.

I keep the lights on when I leave the garage if I plan on being back within an hour to work again, but otherwise, I turn them off.

If you still want me to figure the difference, I could do that also.

Your figures are right except for the amount the balast uses..

That's why the compact florescents are so good.. A 15 Watt CFL replaces a 75 Watt Incandescent bulb..

A 100 Watt INCAN. Bulb takes 10 hours to use 1 kwh.. A 15 watt CFL takes 66 hours to use 1 kwh.. Take that times all the bulbs in your home for a year..

And the CFL's will last at least 8 times longer.. The ones they sell at CostCo are really bright and one of the best values I've seen.. Like 6 bulbs for $12 ..

quote:

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Originally posted by 68F100:
40 watts is 40 watts.
The reason flourescent is cheaper than incandescant is because it runs on much less amperage(ratings should be right on the ballast). More light with less power consumption = more efficient.

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Dave

If youve been looking for an excuse to paint the floor with that nice 2 part epoxy (with flake) coating then this adds an extra dimension. When I painted my floor (its a light pewter color) the whole room brightened up significantly. In one house I lived the walls were bare drywall, and if they had just been painted white it would have really brightened it up.

its $100 to cover the floor in a 2 car garage (using the rustoleum epoxy kit).

I have 2 hanging flourescant fixtures, each one has a pair of 40W bulbs and with my white ceiling, painted walls and shiney floor its like summertime in there. Im also considering putting in some tracklights with spots shining into the middle where the hood of the car is

Here at work in the test cells they also have "waist" that are in the wall about 3 feet up - lights that help illuminate the engines from the side. when the light is coming from every angle you can always see what your working on.

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oddly obsessed with big scoops on little Mustangs

65 coupe 351w C4 Big Boss 429 hood scoop,8" 3.40 TracLoc.