watt
The basic unit of electric, mechanical, or thermal power in the SI and MKS systems, equal
to one joule per second or 10 ergs per second ( of a horsepower): for electric power it is
equal to one volt-ampere.
Now, that's the official definition; why dont we focus on a definition that makes more sense to you and me.
The watt is the starting point for how you are charged for energy, so a watt is tied directly to your wallet.
Taking a few minutes to learn about how watts relate to energy efficiency is an important exercise for those of us who don't understand electricity. Counting watts is thek ey to lowering the cost of energy in your home or place of business.
Most people don't realize that energy efficiency is as simple as a mathematical subtraction problem. Determining the difference in wattage can have a significant impact. Understanding this concept will help you make more informed buying
decisions when purchasing products that use electricity in your home or business.
For an example, we are going to compare two bulbs. The image above shows a 100 Watt standard incandescent bulb. And Below a 23 Watt compact fluorescent bulb.
Both of the bulbs above are suitable replacements and can be utilized for the same application. While the old style 100 Watt bulb will likely be cheaper to purchase upfront, over time the compact fluorescent will save you money. How much difference?
This is where the simple subtraction problem comes in. Using the two bulbs above, we utilize the wattages to do a simple mathematical problem.
Take the 100 Watt incandescent and Subtract the 23 Watt Compact Fluorescent and you find a difference of 77 Watts.
(100 Watts - 23 Watts = 77 Watts Difference).
With this information we can now determine how much each of the bulbs will cost us annually. You’re likely saying to yourself "but my electric company charges me per kilowatt hour (kwh)". Now the math gets a little more complicated, but still manageable.
In order to determine the cost difference between the two, we utilize the wattages to determine the kwh.
We do this with the following equation:
Fixture Quantity x Fixture Wattage = Total Watts
Total Watts / 1000 = Kilowatts
Kilowatts x (Hours of Usage) = Kilowatt/Hr
Kilowatt/Hr x (Cost of Energy) = Annual Cost
Let's assume you have the following:
You have 10 Lights (Fixture Quantity)
The 10 lights have 100 Watt Bulbs (Fixture Wattage for Each) and you want to replace them with 10- 23 Watt Bulbs (Fixture Wattage
for Each) 2000 Hours (Hours of Usage)
$.10 Per Kilowatt/Hr (Average Energy Rate Charged)
How much does it cost annually for 10 - 100 Watt Bulbs?
10 (Fixtures) x 100 (Watts Each) = 1000 Watts
1,000 Watts / 1000 = 1 kw
1 kw x 2000 hrs per year = 2000 kwh (Kilowatt)
2000 kwh x .10 = $200 to operate 10 lamps with 100 Watt Bulbs
$200 to operate 10 100 Watt Incandescent light bulbs
So how does that compare to operate 10 - 23 Watt Bulbs?
10(Fixtures) x 23 (Watts Each) = 230 Watts
230 Watts / 1,000 = .23 Kw (Kilowatt)
.23 Kw x 2000 hrs per year = 460 kwh (Kilowatt Hour)
460 kwh x .10 = $46 to operate 10 lamps with 23 Watt Bulbs
$46 to operate 10 23 Watt Compact Fluorescent light bulbs
"Watt's" the difference?
100 Watts - 23 Watts = 77 Watts
-Or-
$200 - $ 46 = $154 Annual Savings
$154 / 10 Bulbs = $15.40 per bulb
You could spend up to $15.40 per bulb and get 100% payback in the first year.
Many of the bulbs last up to 4 years. If the bulbs pay for themselves in year 1, that gives you 3 more years of savings, or $462 of savings from years 2, 3 and 4.
You invest $154 and in 4 years you get $462 in return.
That is a 300% return on your money.
How much would you have in a bank account if you placed
it in a regular savings account? I can guarantee you it won't
return 300%, maybe 3%.
"Watt" are you going to buy next time?
P Scott Rayburn can be reached for further information
Email: ScottR@LPSolutions-Inc.com
Phone: 901-834-8141
