# Calculating the Costs of Electricity Consumption

## How to turn electricity usage data into dollar figures to help identify potential savings

Part of my job as an energy auditor is educating homeowners around electricity usage. Reviewing and analyzing past usage is part of my process. Checking service conductors and individual branch circuits in an electrical service panel is also sometimes needed. This information tells me if an appliance, motor, or other device is operating as expected.

Electricity usage of a single appliance over time is something to determine too. My energy assessement visits are usually under four hoursâ€”hardly enough time to figure out how often a unit operates. For this, we need tools that can record data.

Some questions I ask of customers include: Are there any new appliances? Is there electric space heating equipment in use? Are you using a vehicle block heater? Are there tank heaters for farm animals?

Then I test inside the electrical panel.

#### Electrical panel testing

When diagnosing a high electricity bill complaint, I have a few different methods at my disposal; testing inside the electrical panel is typically where I begin. First, I view the panel with my thermal imaging camera. If a circuit breaker is, or was recently on, often the breaker will be warmer than the surrounding circuits. This gives me a starting point of where to look.

Note that thermal imaging is effective when the electrical draw is constant. Sometimes loads are intermittent; those donâ€™t always present using thermal imaging, so you have to be lucky to catch the problem another way.

The next step is to use my clamp-on multi-meter to confirm electrical usage. I start by measuring the load on the two main service conductors. This will indicate the entire draw of the panel.

After measuring the load on the main service conductors, I measure the individual branch circuits, trying to determine if any are drawing an unexpected…

### One Comment

1. | | #1

The Sense Energy Monitor is okay - but still very useful. As Randy pointed out - it is still learning some new devices (like dessicant dehumidifier installed in the attic). ECM motors are not easily detected.

• ## Calculating Electric Service Needs

Measuring a home's electric demand determines if the existing service can serve additional loads, such as an EV charger

• ## Whole-House Electricity Monitoring

A look at the functionalities and applications of a newly installed home energy-usage monitor

• ## Data Logging: Types of Monitoring

A look at what can be measured and how to apply the data that loggers track

• ## Performing an Energy Assessment: A Case Study

This often-free service is invaluable when it comes to rooting out sources of extraneous energy usage

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