Part of an energy auditor’s job is energy analysis, which includes historical energy consumption data to determine if usage is as expected. One method is to compare a home’s energy use to some average—the local rural electricity provider I contract with calls this ‘compared to your neighbors’.” This average could be the national average, but it’s better to compare at a more local level, such as by state.

There are a few sources for this information including the U.S. Energy Information Administration – EIA – Independent Statistics and Analysis. This dashboard provides several energy consumption metrics, expressed in MMBtu and kWh, broken down by state; it also displays U.S. national averages. (Sorry, Canadian friends.)

Measuring energy use

Before we dive into the analysis, we should look at the two measurement units used to compare energy usage: Million British Thermal Units (MMBtu) and kilowatt-hours (kWh). One Btu is defined as the amount of energy required to raise the temperature of 1 lb. of water 1 degree; 1 MMBtu equals 1,000,000 Btu.

A watt is a unit of power, one joule (J) per second. As an energy auditor, I look for electricity consumed, which is billed by kWh, or 1000 watts per hour. We can convert kWh to Btu and vice-versa. One kWh equals 3412 Btu; 1 MMBtu is equal to a little more than 293 kWh.

Calculating energy use

Now that we have a basic understanding of the metrics we use for an energy analysis, let’s use the data to perform a basic energy assessment. We’ll use my home as an example (lead image). The house is located in northern Minnesota, Climate Zone 7. It has a conditioned floor area of 2054 sq. ft. It’s primary source of heat is a natural gas forced-air furnace (the only gas-burning appliance). There is also a central ducted…