The crucial first step in lower electric bills is finding out how much electricity is being used by various appliances and lights in your house. Just knowing this, most people change a few habits and end up reducing electricity bills by 5 to 10%. That can be another $100 in your pocket every year. Without even buying any energy-saving devices.

To reduce spending you first need to know where the money’s going. Until you track your spending, you really don’t know what are your biggest expenses and which are unimportant. When you do this there’s usually a few surprises. You’re likely to find you’re spending a lot on things that aren’t very important to you. So you prioritize, and realize some savings.

Saving energy is just like that. Tracking down all the electric loads in you home is a key part of any home energy audit (also called a home energy assessment). Once you have a list of electricity users, it’s easy to see which are the big items, and which surprise you. Often a few simple habits, like turning off lights and unplugging unused items, can result in big savings. That’s how most people save on electricity bills. A substantial purchase, like buying a new energy-efficient refrigerator, is at the other end of the spectrum. Knowing your actual energy use is a great help in going further. It gives you the knowledge and confidence that any purchases are worth their cost in energy savings. In most situations, you can easily cut your electricity bill by 10%, and sometimes as much as 30%.

You Need a Kilowatt Hour Meter

Basic energy audits usually just total typical wattage for each appliance times an estimated number of hours they’re used per day. Light bulbs and most appliances will list their wattage, but it can be hard to estimate how many hours per day they run. This can be especially important (and difficult) for major appliances like refrigerators, washers & dryers, microwaves, etc. Some appliances actual use is significantly less than the nameplate data, and some draw “phantom power” even when turned off.

The utility company has its kilowatt meter installed outside your house. So at no cost you can learn to read wattage and run back and forth turning appliances on and off to determine their wattage. Another type of home watt meter ties into the circuit-breaker of fuse box, and transmits to a portable display. But these usually require electrician to wire into breaker box. They’re more convenient (and fun), but can be rather expensive. But for both types the meter measures monitor the whole house not individual loads. Turning an appliance on and off identifies its wattage, but you still don’t know how many hours per day an appliance like a refrigerator is actually running.

But there’s an inexpensive tool to measure this.

What’s a Kill A Watt?

The aptly named Kill A Watt P3 is a great tool for cutting your electricity costs. The Kill-A-Watt model P4400 is a very easy to use electricity monitor that tells you exactly how much each appliance or lamp in your home is using. There’s no need for an electrician. You just plug it into the wall, then plug any 110/120 volt item you want to monitor into it.

P3 International makes several models. The P4400 has long been the “standard” home watt meter. Although the list price is around $50, you can find them for $30 or less, so it usually pays for itself several times over in just the first year of savings. Although inexpensive it’s quite accurate, specified as 0.2%. All the Kill A Watt models actually make several measurements. You can display voltage, amperage, wattage, power factor, and line frequency. And of course it’s a power usage monitor. As soon as you plug it in it automatically starts totaling watt-hours used and how many hours its been measuring. The P4460 is a bit more expensive but retains it’s power usage data if power is turned off and will convert its readings into daily, weekly, monthly, and annual costs.

Ready? Go!

Knowing your home’s “energy budget” is the key to lower electricity bills. All the Kill A Watt P3 models provide accurate measurements of the electrical power actually drawn by plug-in appliances. This is particularly important for appliances such as refrigerators (one of the largest home electricity users) where you don’t know exactly how many hours they run each day. A new energy-efficient appliance will save on electricity bills, and a home watt meter will tell you if the savings are worth the cost. Many home devices such as TVs use “phantom power” even when you think they’re off. The only way to find this for sure is to measure it. If it’s significant, then you’ve found an easy opportunity for reducing electricity bills.

I’ve always been a geek doing “science projects.” The Kill A Watt P3 power meter is one of my favorite toys. Er, tools.