How to measure your environmental impact at work: Electricity

measure your impact electricityThe Green Team ROI Tracker, True Impact’s latest web-based measurement tool, helps calculate the impact of employee-led sustainability projects. This series provides step-by-step instructions for how you can measure the impact of your own Green Team initiatives, using frameworks embedded in the ROI Tracker.

Green teams aim to reduce electricity usage in their corporate offices in order to reduce their  company’s greenhouse gas emissions, cut costs, and promote more responsible practices. This post will guide you through a range of energy reduction techniques -- including tactics for reducing power consumption of computers, monitors, and office kitchen appliances -- and then walk you through steps for tracking and measuring the impact of such practices.  Heating, cooling and lighting also contribute to electricity usage; those topics will be covered in other posts in the How to Measure Your Environmental Impact at Work series.

Ways to Conserve at Work

When seeking to reduce electricity usage in the workplace, consider the following best practices:

  • Create an Employee Energy Conservation Challenge L'Oreal's "I've Got the Power" program, for example, successfully reduced corporate energy consumption by appointing employee “Energy Champs” and leveraging social media.
  • Upgrade to ENERGY STAR products - ENERGY STAR a well-respected, government-backed symbol for energy-efficient products and practices, designed to help consumers save money and protect the environment.
  • Encourage employees to shut down computers - Ford Motor Company estimates that “powering down” computers not in use translates to more than $1.2 million in savings and a reduction in Ford’s carbon footprint by 16,000-25,000 metric tons annually.
  • Implement energy treasure hunts – First developed by Toyota, Energy Scavenger Hunts are hands-on events that turn energy audits (seeking opportunities to reduce energy consumption) and a scavenger hunt.
  • Use a power strip to avoid “Phantom Load” –  Phantom Load, also known as “vampire power” and “idle current,” describes electricity that electronics and appliances use while they are turned off or in standby mode. Unplugging electronics or using a power strip to turn off power can decrease this energy use.

Whatever approach(es) you choose, the best time to plan how to measure the impact of your efforts is prior to implementation.  The following sections provide some guidance.

Measuring Electricity Conservation

Determining the impact of your energy conservation efforts means evaluating the resulting change in electrical usage, measured in kilowatt-hours (kWh).  Note:

  • A watt is the electrical unit of power.
  • A watt-hour is equal to 1 watt of power supplied to an electric circuit for 1 hour.
  • A kilowatt-hour (kWh), the equivalent of 1,000-watt hours.

To determine the number of kilowatt-hours your Green Team has saved, do your best to determine how much energy usage has changed after the implementation of your initiative compared to beforehand (accounting for external factors such as time period and weather conditions). If your building and facilities managers do not have data on your electricity usage, here are two other ways to measure reductions in energy use:

Option 1: Manual Estimates

A quick internet search or review of device user manuals will give you the energy use for specific devices, or you may find any of a number of web-based calculators that will do this calculation for you, such as the kWh Energy Savings Calculator at Pays to Live Green. Note that some devices, like computers, use different levels of electricity based on their usage. Example ranges of device wattage include:

electricity wattage

Source: Estimating Appliance and Home Electronic Energy Use

Once you have the wattage of the device, determining how much energy it uses is straightforward arithmetic:

  • (Wattage × Hours Used Per Day) ÷ 1000 = Daily Kilowatt-hour (kWh) consumption

More detail on the application of this formula is available at

Option 2: Actual Tracking

Alternatively, use a power meter like the Kill a Watt to establish actual baseline usage (i.e., how much energy is consumed before your initiative), and then measure the change in energy usage after your initiative. Measuring unit change is ideal for a localized program like Energy Treasure Hunts and campaigns to power down computers when not in use.

Measuring the Impact of Electricity Conservation

Once you track or estimate your reduction in energy usage, you can translate this change into impact on greenhouse emissions and cost savings using various information sources:

Option 1: Manual Calculation

To most accurately assess cost savings, contact your building manager for your actual cost of electricity, and then multiply the amount of energy saved by the cost per kilowatt-hour.  The average retail price in the US in 2010 was 9.83 cents/kWh, with average state prices for electricity ranging from 6 to 25 cents per kilowatt-hour (source: the U.S. Energy Information Administration).

The majority of electricity in the United States is generated from fossil fuels such as coal, natural gas, and oil.  The burning of these substances emits CO2 into the atmosphere. By reducing your usage, you are decreasing your emissions at the average rate of 6.9 x 10^-4 metric tons of CO2/kWh. (Source: EPA).

Option 2: Automatic Calculation

A variety of calculators exist in the public domain that incorporate average values of electricity usage and cost to help you estimate your impact.  The EPA and ENERGY STAR have, for example, created a simple calculator (click here to download the Excel calculator) to estimate typical savings from ENERGY STAR qualified computers and/or power management features.

True Impact’s Green Team ROI Tracker uses a similar approach, but for a broader range of sustainability initiatives, converting them to metric tons of CO2 reduced and kilowatt-hours and dollars saved.

measure electrical conservation

For more measurement tips for Green Teams, see our comprehensive Green Team ROI Tracker Measurement Guide. To learn more about True Impact’s measurement work, get in touch.

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