The Power Panel Profiler is a comprehensive MS Excel Workbook designed to tabulate and analyze all of the electrical loads in your home. If you have not already done so, please sign up for our E-zine called the Meter Messenger to receive your FREE Profiler download:
The Power Panel Profiler is a tool you can use to become your own energy auditor. It is built around a 40 circuit, 200 amp electrical panel typically found in most homes. If you have a larger home with 400 amp service coming in through two 200 amp panels, simply analyze each panel with a separate profile.
The same is true for larger sub-panels carrying more than 8 circuits. The goal is to identify and measure every load on each circuit down to the last outlet. This is where home energy monitor systems and plug-in meters are put to work to reduce your energy bill.
By measuring or estimating the average amount of time each load runs per day, the software will calculate the kilowatt hours flowing through each breaker. This individual breaker information rolls up to create the total electrical load for your home. When matched with your electric bill, it itemizes usage in very fine detail.
Gathering and loading this information into the worksheet will take some effort but the benefit will be worth it. You will gain a thorough understanding of how electricity is distributed in your home. You will discover things that can be shut off, locations for power strip timers, dimmer applications and great places for all sorts of other energy saving ideas.
Once you have established a baseline, make copy of the Power Panel Profiler and update it with new data as you apply energy saving ideas. Compare the result with your original baseline and watch your energy bill savings mount up.
Note that data can only be entered into cells highlighted in color. All other cells are protected to prevent inadvertent erasure of formulas.
2. Evaluate your first circuit. Choose a simple one such as a set of outlets for one or two rooms. If you are not sure which outlets are on which circuits shut off the breaker. Go test each outlet with a test light. Flag the cold outlets with the breaker number written on a piece of tape.
Make a list of each device plugged into those flagged outlets and identify the load associated with it. Turn the breaker back on and use your plug-in meter to get an accurate wattage measurement of each device. Record the voltage, power factor and wattage for each device under the proper circuit number in the appropriate Power Panel Profiler worksheet. Measure or estimate the number of hours per day each device is powered on and enter it as well.
3. Evaluate the remaining circuits. Repeat Step 2 for each circuit in the panel and enter the information into the appropriate worksheet in the Power Panel Profiler. Realizing not all circuits will be as easy to measure as those you can plug in, here are some suggestions:
b. Refrigerator and Freezer - Measure for 24 hours using a plug-in meter to get kilowatt-hours per day. Divide the kilowatt-hours per day by instantaneous kilowatts of load to determine run time per day.
c. Hard-wired Appliances - (eg. dish washer, cook top vent, microwave) Use your home energy monitor system to measure the total load before and after the device is turned on. Take several readings to be sure another device does not interfere. Subtract to determine the difference. This will be the wattage for the device. This technique will require system accuracy to be within +/-10 watts for good results but +/-1 watt is better.
d. Home Entertainment Systems - Use a power strip meter. Turn components on and off noting the change in load and record the difference. Record actual usage over a week long period and divide by 168 (hours in a week) to get a good average of hourly system load. Pay particular attention to vampire loads that remain on all the time. This may be a good location for a power strip timer.
e. 240 Volt Loads (eg. range, hot water heater, heat pump) Use your home energy monitor system as noted under section 3.c. above to determine wattages by switching the devices on and off. Electric hot water tank placards are fairly accurate as the load is simply resistive. Wattage can be recorded from the placard and entered directly into the Profiler.
Another option is to use load profile software,
such as that offered with Energy Inc.'s TED 5000, to determine daily run time.
This software can also identify the wattage of specific loads such as air conditioners
or heat pumps by using the "Learn" feature. Once programmed, daily run times for
these devices can be captured as well.
Note: When entering 240 volt loads into the worksheet, set the voltage to 120 V. (line to neutral) for each line and enter the wattage as it appears on the meter for both A and B lines. Hours of run time should also be the same for both legs. This allocates the proper amount of connected load to each incoming line.
f. Obscure loads (electric heat strips, specialty equipment) Those loads that are difficult to to measure such as electric heat strips, the defrost cycle on a heat pump or special shop equipment may require individual breaker measurements. The extra channels, available on multi-point or circuit level metering systems, can be used to track these loads. However, an additional set of current transformers (CT's) will be needed.
If additional measurement points are not available, use your home energy monitor system as described in 3.c. above. As an energy auditor you may need to make a few assumptions to completely fill in all the blanks in the Power Panel Profiler. That's OK. We'll verify those assumptions in the next step.
4. When all the circuit data is loaded into the Power Panel Profiler worksheets, compare the total estimated kilowatt hours for the month with your electric bill. It should be within +/- 10% of what the utility is measuring. If not, go back and revisit the run time estimates you made on the larger loads.
Keep in mind that seasonal differences in the run times of HVAC equipment will be significant. You may wish to create a Spring/Fall, Summer and Winter profile by adjusting the daily run time on those breakers serving HVAC circuits. Treat other seasonal circuits such as pool pumps or holiday lighting accordingly.
5. From your electric bill enter the customer charge, the net cost per kilowatt-hour and the tax rate on the Home Page.
When you are satisfied your home energy audit is an accurate reflection of your electric usage you have a baseline! Save this file and do not change it. Make a copy of the file and use it to track changes as you implement energy saving ideas into your home.
For example, enter run time changes on circuits after installing power strip timers or smart switch strips. Enter lower wattage readings when compact fluorescent bulbs replace conventional ones. Click here for more energy saving ideas.
Compare your updated file to your baseline file and, over time, you will see your energy savings grow.