Re-energizing Walkthroughs

Re-energizing Walkthroughs

Energy audits can identify low-cost opportunities to reduce waste.

When President-elect Barack Obama takes office in January, one of his priorities will be the implementation of an energy plan that is expected to include a carbon cap-and-trade program. Such a system would put a limit on how much carbon dioxide and other greenhouse gases could be emitted by industry.

Under a cap-and-trade system, energy-intensive manufacturers would be forced to identify energy-reduction opportunities. As part of their Energy Star program, the
Department of Energy (DOE) and the Environmental Protection Agency (EPA) have encouraged manufacturers to perform energy audits as a way to pinpoint energy waste sources.
Assessments can be conducted by the plant itself, an outside consultancy firm or plants selected for the DOE's Save Energy Now audits. (For information about DOE assessments, visit

The DOE recommends three types of assessments that vary from a basic walkthrough to a thorough long-term analysis. Energy audits can include:

  • A walkthrough that looks for the low-hanging fruit, such as idle equipment or inefficient lighting. These assessments are typically low-cost and may take two to three hours to complete.
  • A review of support systems such as compressed air, motors and steam. The audits could be conducted by a corporate team supplemented by experts for major support systems. They're slightly longer than a walkthrough and can provide specific findings for utility systems.
  • A process/yield study, which is a detailed, full-site review often used by companies to increase plant yield. These assessments can last months in duration and usually include external expertise on the audit team. They're more costly but typically provide greater savings potential.

Since 1995, Detroit utility company DTE Energy has worked with Ford Motor Co. on several energy surveys. Ford has realized energy savings of more than $40 million as a result of energy-savings initiatives implemented after the DTE assessments, according to an EPA case study. One of DTE's top priorities when assessing a plant is how a company is using compressed air, says George Biandis, principal supervisor for DTE. "The reason for that is it's usually your most expensive utility or process supporting plant operations," Biandis says. "Typically, upward of 20% of their electric bill can be dealing with compressed air."

In terms of the specific issues with compressed air, Biandis says he looks for how the company operates its compressors in relation to its demand. That's because for every 2 pounds per square inch that a manufacturer can reduce its pressure, it can reduce its electric costs by about 1%, Biandis says. Other contributing factors to compressed air waste include leaks and employee misuse of tools for applications that could be carried out with another less energy-intensive method.

In many plants, employee behaviors impact energy waste more than the equipment itself. "We can walk through most facilities and without any capital investment reduce their electric load or demand 10%, and that's just by a matter of manual intervention by the people -- shutting off lights, shutting off any kinds of personal fans they use," Biandis explains. "A lot of times we see, especially in the winter time, exhaust fans that are not process related where I don't have a problem with air quality issues. We see people run those fans, and it's just taking the heat right out of the building."

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