# When Should You Turn Off Your Lights?

When Should You Turn Off Your Lights?

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1. Should you turn off your lights every time you leave the room? How much energy does turning your lights off every time you leave a room save? Does turning your light off save you money or does turning your lights off cost you money? The answers to all these questions depend on the lights involved.

Turn Off Incandescent Lights When Not Being Used.
The number of hours before burn out for any light bulb is shortened every time you turn it on and off but incandescent light bulbs are relatively inexpensive. The cost of the energy that you will save will outweigh the cost of replacing them more often. Incandescent light bulbs waste 85 to 90 percent of the electrical energy that they consume, only 10 to 15 percent is converted to useful light energy, the rest is wasted as heat energy. Turning off incandescent lights reduces the cost of cooling your home.

Turn Off Fluorescent Lights When Not Needed For Fifteen Minutes Or Longer.
Fluorescent light bulbs are more expensive to replace than incandescent bulbs; therefore, it is a trade off between energy savings and the cost of more frequent bulb replacement. It is a myth; fluorescent lights do not consume more energy when starting then they consume when running. The high inrush current that it takes to fire the bulbs last for one half cycle or 1/120th of a second. Turning off fluorescent light for more than 5 seconds saves energy.

How Much Money Will You Save?
Calculating the exact amount you will save by turning off a light is simple math. Simply divide the wattage rating of the bulb by KW to determine the energy consumed in an hour’s time e.g. 40W/1000W=0.04W per hour for a 40W bulb. To convert to dollars, multiply by the cost per Kwh. If your energy cost is 10 cents per Kwh multiply 0.04W X 0.10 = \$0.004 per hour. A single 40 Watt fluorescent light fixture with four bulbs would cost 4 X 0.004 =\$0.016 per hour.

The best way to save energy and money is to switch to Light Emitting Diodes (LEDs) lights. The initial cost of an LED bulb that screws into an incandescent lamp socket is greater than the cost of an incandescent bulb but they have a life expectancy of 50,000 hours compared to 100 hours. Light Emitting Diodes generate no measurable heat and consume a fraction of the energy consumed by an incandescent bulb of the same wattage.