You are here

Ever Wonder...What's in a Watt?

Friday, April 8, 2011

Just flick a switch and let there be light (or boiled water, or Blu-ray, or a night’s charge for your smartphone): 

A lifestyle that would have seemed like magic to many people even 100 years ago is now something we pretty much take for granted.

In all your daily hustle (and – likely – bustle) have you ever stopped to wonder what it takes to keep you in the electrified, digital lifestyle to which you’ve become accustomed? 

One of the easiest ways to see it all in action is to uncover just what’s in a watt…

Electricity unraveled

To put it most simply, the watt (W) is a standard unit which you can use to measure your personal power consumption. 

Named after James Watt (1736-1819), the Scottish inventor who refined the steam engine, a watt (W) is a unit of power that describes the rate at which energy is converted (i.e. the rate at which you are using energy). 

As you may remember from high school physics:

     1 watt = 1 joule per second
     (note: energy is measured in joules)

     1 watt = lifting 1 deck of cards from the ground onto a poker table

So what about 100 watts?

     100 W = lifting 100 decks of cards from the ground onto a table in 1 second

     100 W = the power of the incandescent light bulb that’s illuminating my 
     workspace as I write this (I know, it needs replacing)

We may be most familiar thinking about watts in terms of light bulbs, but not all of our power consumption comes conveniently stamped with a wattage number. So how do we determine the rate at which we are using energy?

Your monthly energy bill could be a place to start. It provides you with a measurement in kilowatt hours (kWh). Note that a kilowatt is simply 1000 watts. 

     1 kWH = wattage in kilowatts x hours used

So if I left the 100 W light bulb that’s shining on me right now burn all month (730 hours), it would require 73 kWh:

     73 kWh = 0.1 kW x 730 hours

If I replaced my 100 W incandescent light bulb with a 25 W compact fluorescent, I would cut down my electricity bill to 18 kWh: 

     18 kWh = 0.025 kW x 730 hours

Unfortunately, your standard energy bill doesn’t provide a detailed breakdown of where all your kilowatt hours are coming from.

Making the system work for you

Enter watt calculators: While these types of tools are still being refined, like carbon footprint calculators, they can provide a surprising perspective on the energy intensity of your lifestyle. 

For example, features a free tool to quantify your personal power consumption which uses crowd-sourcing to increase accuracy. It uses watts instead of kilowatt hours in order to simplify the calculations by taking time out of the equation.

You can use such online tools to get a sense of your own energy consumption and compare yourself to others to see how you fare. 

Energy reality

More than looking at the kWh total on your monthly energy bill, the specific outputs of power-consumption tools can provide you with a real sense of your actual power use. 

This sort of detailed understanding of your personal wattage can help you make more energy-efficient lifestyle choices when the wattage isn’t listed on the box.

What’s your wattage or your new wattage goal?

Figure it out using WattzOn and post to our Facebook page.


Written by: Lisa Lambert