Energy Benchmarking Process LL84

What Does the Energy Benchmarking Process Entail?

Energy benchmarking is a tool that enables one to use the energy information of a building similarly to the way a Miles Per Gallon (MPG) rating would be used to assess a car’s operating performance. A general overview of the energy benchmarking process is described below.

Utility Data Collection

Generally, energy benchmarking begins with the collection of a building's utility data for the most recent year in the form of energy bills or via access to the client's utility account. The information supplied will include location, size, number of occupants, hours of operation, number of PCs used etc. Once data has been obtained, it is converted into the correct format to perform a formal analysis.

Energy Assessment & Analysis

Before energy data can be analysed, baseline consumption is established by using energy data from a previous year. This allows for comparison among the current energy usage levels and the historical consumption of the facility. The data is input into an energy management and assessment tool such as EPA's online tool, Portfolio Manager. Source and site energy usage intensity (EUI) calculations are also performed for further analysis & comparisons. Energy usage intensity is the energy used per square foot; Source EUI is the most equitable unit of evaluation since it takes into account all energy use by incorporating all transmission, delivery & production losses.

Energy Star Scores & Ratings

An important goal & result of the energy benchmarking process is to compare energy & water usage of a building to that of its peers nationally. For commercial buildings, this is accomplished through  a 1-100 ENERGY STAR score that allows owners, managers & residents to understand how their building measures up against similar buildings nationwide. This score is calculated on the basis of actual, measured data. It provides information on the building's operations, assets & energy usage behaviour of its residents. For instance, the score indicates whether the building operates 24 hours, has a high density of workers, peak energy usage times, etc.  Additionally, all calculations are performed using source EUI and are normalized to account for weather variations in different regions.